distribution and exploitation of the long-clawed crayfish

Distribution and Exploitation of the Long-Clawed Crayfishte
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Biology of Freshwater Decapods Frankfurt a. M.
December 8-10, 2010
PLENARY TALK
NEIL CUMBERLIDGE
Crab and Crayfish Specialist Group,IUCN Species Survival Commission
Freshwater ecosystems host a diverse endemic fauna including freshwater crabs, crayfish, and shrimps but freshwater habitats, and the animals that depend on them are now under imminent threat. Recent IUCN Red List assessments of the freshwater decapods around the world have revealed unexpectedly high threat levels with significant numbers of species threatened with extinction. The majority of imperilled decapod species are restricted-range endemics living in habitats subjected to deforestation, alteration of drainage patterns, pollution, and over-harvesting for human consumption. I review here the current strategies aimed at monitoring and quantifying the decline of the World’s threatened freshwater decapod species, and the efforts being taken to develop conservation measures to prevent further losses. Strategies for the sustainable management of inland aquatic resource depend heavily on baseline data on the diversity, conservation status, and distribution patterns of the freshwater decapod faunas. The growing pressures on freshwater habitats and their species make it a priority to understand the effectiveness of current conservation strategies at the global and national levels in protecting freshwater systems and their inhabitants. It is clear that we are rapidly losing a good part of the biodiversity of the freshwater realm worldwide, and trends indicate that this situation is becoming increasingly serious. Future challenges include an increasing human population placing pressures on water resources for food, energy, transport, and water supply, and by the emerging threats to freshwater ecosystems posed by global climate change.
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Oral presentations
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Astacus leptodactylus in Iran
Inland water Aquaculture research institute, P.O.Box 66, Bandar Anzali, Iran
The Long-clawed Crayfish (Astacus leptodactylus ) is the only crayfish species found in the freshwater environment of Iran. Astacus leptodactylus is a native freshwater crayfish, naturally distributed in some lakes, ponds, reservoirs and rivers of Iran. This species has also been stocked in some freshwater systems in Iran to establish new populations. In the years 2000-05 Astacus leptodactylus was introduced from Arass reservoir to 34 water bodies of 13 provinces.
At present, there is only one commercial crayfish harvesting area in Iran adjacent to Arass reservoir in the Northwestern part of the country in Western Azerbaijan Province. Between 1996 and 2007, the harvest of A. leptodactylus in Iran from the Arass reservoir has increased from 11.7 tonnes to 240 tonnes in 2007.But some sign of overfishing has been observed in this ecosystem.
Approximately 23.6 tonnes of A. leptodactylus were harvested from some lakes in Eastern Azerbaijan , Ardabil and Zanjan Provinces.
The stock of A. leptodactylus in Anzali lagoon has been damaged due to over-fishing, water pollution, water withdrawal for agricultural Irrigation and recent years of drought. In 1985 about 11 tonnes of A. leptodactylus have been harvested from Anzali lagoon and exported to Turkey.But after that there was very low harvest of this species from Anzali lagoon.The population of A. leptodactylus has been disappeared from some localities of this waterbody.
Pontastacus eichwaldi is distributed throughout the coast of the Middle and Southern Caspian Sea. Investigation showed that there is some population of this species in Bandar Anzali coastal waters in a depth range from 35 to 100 mm. Experimental harvest of Pontastacus eichwaldi from the Caspian Sea in Bandar Anzali was only about 700 kg in 2007 and 2008.
As crayfish are sensitive to water quality, For sustainable exploitation, the crayfish populations should be carefully monitored in introduced water body.
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Multiple Invasions of Freshwater by a Genus of Shrimp
Revealed Through Molecular Analysis
CHRISTOPHER W. ASHELBY1,2, TIMOTHY J PAGE3, SAMMY DE GRAVE4 & MAGNUS JOHNSON1
1CEMS, University of Hull, Scarborough Campus, Filey Road, Scarborough. YO11 3AZ. United Kingdom.
2Thomson Unicomarine, 7 Diamond Centre, Works Road, Letchworth Garden City. SG6 1LW. United Kingdom. 3Australian Rivers Institute, Nathan Campus, Griffith University, Queensland, 4111, Australia.
4Oxford University Museum of Natural History, Parks Road, Oxford OX1 3PW. United Kingdom
The transition into fresh water requires many physiological and life history adaptations
and is one that few faunal groups have made. Of those that have, crustaceans are amongst the most successful with the Decapoda being well represented in freshwater. Eight caridean shrimp families contain species found in freshwater, numerically dominated by the Atyidae and Macrobrachium. The subfamily Palaemoninae is widely believed to be radiating into freshwater from ancestral marine stock with the large genus Macrobrachium being essentially confined to fresh- and euryhaline water. Other species rich palaemonid genera in freshwater are Palaemonetes and, to a lesser extent, Palaemon. Although traditionally these two genera were separated only on the basis of the presence or absence of a mandible palp in Palaemonetes, several studies have questioned the utility of this character, although none have suggested merging both genera. Some previous morphological and molecular studies have also suggested that both Palaemon and Palaemonetes may be paraphyletic. A phylogenetic study of these two genera, based on 16S rRNA and Histone, recovered them as a single, monophyletic clade and revealed that the freshwater species are not closely related to each other, but instead group with geographically close marine species. This suggests multiple invasions of freshwater rather than a single colonisation event with subsequent speciation. In each geographic region the freshwater species are believed to be derived from one or more physiologically plastic ancestral species with the highest diversity of freshwater taxa occurring in eastern America where 62% of the species are found in freshwater. A review of other freshwater species across all invertebrates suggests that the situation in Palaemon/Palaemonetes may be unique in that they comprise a monophyletic clade with a worldwide distribution, but with approximately half the species being marine and half being freshwater and the freshwater forms resulting from at least 7 independent invasions.
Dosimetric Induction of N Acetyl Glucosamine Specific Hemagglutinin (HA) in the Crab Paratelphusa jacquemontii
MICHAEL RAJAM BASIL-ROSE, JOSEPHINE PRIYATHARSHINI CHELLAPPA
& VINOLIYA JOSEPHINE MARY JOHNSON
Department of Zoology, Holy Cross College, Nagercoil, Tamil Nadu, 629004, India.
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21st International Senckenberg-Conference: Biology of Freshwater Decapods
The hemolymph agglutinin of the fresh water paddy field crab Paratelphusa jacquemontii agglutinated rabbit erythrocytes much better than other erythrocytes. When the haemolymph is preadsorbed with erythrocytes of a particular species, its ability to agglutinate erythrocytes of any species is lost suggesting the presence of a single haemagglutinin in the haemolymph. The haemagglutination titer is enhanced when the surface glycoprotein of erythrocytes are cleaved with proteases suggesting that the receptor of the agglutinin may be masked by the surface proteins. However, the HA titer is significantly reduced after Clostridium perfringens neuraminidase (Type X) treatment of erythrocytes. The GluNac specificity is confirmed by inhibiting agglutination with sugar such as N-acetyl glucosamine>N-acetyl neuramininic acid> N-acetyl galactosamine> N-acetyl mannosamine. Of the sialic acid containing glycoconjugates, BSM was the potent inhibitor of hemolymph agglutination. The HA activity is optimal at pH 6.5 -7.5 and at 30 C. HA titer is enhanced by 10mM Calcium (Ca), while 10 mM EDTA decrease the same. Interestingly Magnesium (Mg) did not affect HA at any concentration. The hypothesis that the invading pathogens may induce HA was tested by inflicting injury and autotomy to the crabs as well as by injecting different concentrations of the erythrocytes. Strikingly, the HA titer was augmented by the injected erythrocytes or by inflicting injury but not by autotomy. Differences were observed in the level of induction with agglutinating and nonagglutinating erythrocytes. The HA production increased with increase in concentration of the injected erythrocytes provided the concentration of the injected erythrocyte is not fatal to the animal.
Chela Polymorphism in Adult Males of Aegla perobae (Anomura: Aeglidae)
SÉRGIO L. S. BUENO, BRUNO F. TAKANO, FELIPE P. A. COHEN
& ROBERTO M. SHIMIZU
Institute of Biosciences - University of São Paulo, Brazil.
Carapace length (CL; rostrum excluded) and propodus length (PL) and propodus height (PH) of the major claw were measured with a digital caliper to the nearest 0.01 mm. Separation of data into juvenile and adult groups was based on the average size at the onset of morphometric maturity (= 9.11 mm of CL) in males of Aegla perobae. Analyses of the lnPL vs. lnCL relationship in adults (K-means clustering analysis) allowed classification of data points into two sets that differed in CL but were overlapped through virtually all CL range. To clarify the biological meaning of this pattern, further analyses based on chela shape (PH vs PL relationship) were performed. Visual inspection of lnPH vs lnPL scatter plot of the overall adult dataset suggested a non-linear relationship which became more evident when residuals of the ln[PH] vs. ln [PL size classes] regression was against ln[PL size classes]. The same
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pattern was also observed in each of the previously separated adult groups. Subsequently, each previously separated dataset was further classified into two groups. The linear regression equation and coefficient of determination for each group of data points were: lnPH = 1.1074lnPL – 0.76; r² = 0.9746 (group I); lnPH = 1.082 lnPL – 0.6721; r² = 0.9682 (group II); lnPH = 0.9988 lnPL – 0.5022; r² = 0.9741 (group III); and lnPH = 0.907 lnPL – 0.216; r² = 0.9538 (group IV). All regression lines differed in slope, except between groups I and III which differed in elevation (ANCOVA). These four groups were interpreted as morphotypes characterized by a change in the relationship in claw dimensions. The temporal sequence of lnPL vs. lnCL plots in which morphotypes were distinguished suggested that there is an association between their sequential appearance in the population and the reproductive cycle of the species. Aegla perobae reproduces twice during lifetime and each reproductive period is markedly seasonal (5 months). Morphotype I males appear in the population after the puberty molt and later give rise to morphotype II individuals as the beginning of the first reproductive period approaches. Morphotype III males derive from the latter morphotype after mating and change into morphotype IV individuals in preparation for the approaching second reproductive period. Morphotypes I and III may thus be viewed as reproductively resting males while morphotypes II and IV may be regarded as functionally reproductive males. Research grants (SLSB): FAPESP (# 2008/57128-0) and CNPq (302663/2009-6)
Estimating the Population Size of Aegla perobae (Anomura: Aeglidae) by Mark-Recapture Technique
SERGIO L. S. BUENO, BRUNO F. TAKANO, FELIPE P. A. COHEN
Aegla perobae is a critically endangered species, with known geographic distribution
restricted to nine small streams in the County of São Pedro, state of São Paulo, Brazil. The estimated area of occupancy of the species is very small and fragmented, totalizing approximately 0.0135km². The population from the type-locality (22°31’26.6” S; 047°56’37.6” W) was selected for the estimation of population size by means of the Schumacher and Eschmeyer method for closed populations and the use of mark-recapture technique. Four quarterly estimations were performed (from austral autumn 2009 through summer 2010), each of them based on data collected during 7 consecutive days. During each 7-day working period, a section of the stream was isolated with fishing net to prevent migration of aeglid specimens. These anomuran decapods were collected with the aid of traps baited with commercial cat feed pellets and randomly distributed within the working area late in the afternoon and checked in the following morning. Classification of captured individuals into juveniles or adults was based on the average size at the onset of morphometric maturity (= puberty moult) for each sex: 9.11 mm and 7.80 mm of carapace length for males and for females, respectively. Population size estimation results refer to adult individuals only. All
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adult unmarked individuals were sexed, measured (carapace length, rostrum excluded) and marked on the carapace with a mixture of super glue (cyanoacrylate) and commercial dye (fine powdered silver purpurine). Previously marked (recaptures) and newly marked (new captures) adult individuals were randomly released back to the isolated area soon after all measurements and observations were complete. Position of marks on the carapace was standardized for each estimating period, but differed from one season estimate to another to avoid biased data collection. Results of the first three estimations are shown in Table below. Table: Aegla perobae. Three population size estimations from an isolated area of the stream from the type-locality.
Season/Year
section
Density (Indiv./m²)
Lower and upper limits of confidence
level (95%) Autumn/2009 1286 142.05 9.1 1176 - 1420 Winter/2009 698 164.76 4.23 666 - 732 Spring/2009 365 165.50 2.21 318 - 430
The population size of Aegla perobae adults decreased alarmingly at each successive
estimating event. By the fourth estimation event in the summer of 2010, aeglids were sampled in such low numbers that estimation of the population size by was not possible. The main cause of the observed population decrease was attributed to abnormal high rainfall regime recorded for the area during early 2008 and 2009, causing great disturbance in the stream and may have affected negatively the successful recruitment of two successive cohorts that were born in 2007 and 2008, respectively. Research grants (SLSB): FAPESP (# 2008/57128-0) and CNPq (302663/2009-6)
Reproductive Biology in Females of Aegla perobae (Anomura, Aeglidae)
SÉRGIO L. S. BUENO, BRUNO F. TAKANO, FELIPE P. A. COHEN
Determination of the reproductive pattern is an important information for animal population management concerning the preservation of endangered species. Aegla perobae Hebling & Rodrigues, 1977 is endemic to Brazil, with known geographic distribution limited to nine small streams, including the type-locality (22°31’26.6” S; 047°56’37.6”W), in the County of São Pedro, state of São Paulo. The population from the type-locality was selected for a 2-year study on reproductive biology, based on female specimens. Samplings were performed monthly from July 2008 through June 2010 with the aid of plastic traps baited with
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commercial cat food pellets and distributed randomly in the bottom of the stream. Captured animals separated according to sex and had their carapace length (CL; rostrum excluded) measured. The definition of reproductive period was based on the observation of ovigerous females sampled during the 2-year study period. Average size at the onset of functional maturity and fecundity were estimated from data obtained from the complete reproductive period observed in 2009. Average size of functional maturity was determined as the CL size at which 50% of the females sampled during the reproductive period were considered sexually functional adults (observation of late ovarian development or the ovigerous condition), by interpolation of the logistic equation PAF=1/1+e(-a-b*CLC) fit on plots of proportion of adult females (PAF) vs. CL classes (CLC) mid-points. Determination of fecundity was based on eggs at early embryonic stage, counted from live specimens without removing them from the pleopods. All sampled individuals were returned alive to the stream after all measurements and biological observations were complete. The reproductive pattern of Aegla perobae is markedly seasonal, taking place from April to August (5 months) or from mid-austral autumn to late winter. Average size at the onset of functional maturity was estimated as 10.46 mm of CL. Number of eggs (NE) at early embryonic stage varied from 30 to 166 (10.26 and 15.74 mm of CL, respectively), with mean fecundity of 91.86 eggs (n = 21), which corresponded to a female with 13.52 mm of CL. The relationship between fecundity and CL size was described by the equation: lnNE = 2.3378lnCL - 1.5671 (r² = 0.48). Research grants (SLSB): FAPESP (# 2008/57128-0) and CNPq (302663/2009-6)
Chinese Mitten Crab and Chips
PAUL F. CLARK
Crustacea Research Group, Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD, England
The invasive Chinese mitten crab, Eriocheir sinensis MILNE EDWARDS, 1853, in the Thames continues to increase in numbers and expand its distribution westward. This brachyuran species is considered to be a delicacy in many SE Asian countries when its gonads are ripening and fully developed prior to mating. Maturity occurs during the autumnal months when mitten crabs migrate in large numbers from freshwater streams to higher salinity brackish waters of the estuary where mating occurs. Up to $40 can be paid for a single mature mitten crab in the right condition at high-class restaurants. Consequently commercial exploitation of mitten crabs may be a viable method of reducing the population size in the Thames catchment. A recent study undertaken by members of the Zoology Department would indicate that Thames mitten crabs are fit for human consumption and that the population is large enough to exploit. However there are still many major issues that need to be discussed - basically do we really want to start a mitten crab fishery in the Thames?
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Population Structure of Aegla paulensis
(Decapoda: Anomura: Aeglidae ).
FELIPE P.A. COHEN, BRUNO F. TAKANO, ROBERTO M. SHIMIZU & SÉRGIO L.S. BUENO
Specimens of Aegla paulensis were sampled monthly from a small creek at Jaraguá State Park, São Paulo, from September 2007 through August 2009. Traps were used to capture over five thousand individuals, which were sexed, measured (carapace length = CL) and inspected for reproductive traits (females only), and then released back to the sampling site. The pattern of the reproductive cycle is strongly seasonal (austral mid autumn through late winter), with one single recruitment pulse per year. The obtained von Bertalanffy growth equations were CL=21.25[1-e
-0.041(t+1.250) ] and CL=16.52[1-e
-0.049(t+1.823) ] for males and
females, respectively. Males (mean CL ± s.d = 11.86 ± 2.79 mm) attain larger sizes than females (mean CL ± s.d = 10.84 ± 2.36 mm). Aegla paulensis reproduces twice during an estimated life span of 40.2 months for females and 33.9 months for males. Temporal variation of sex-ratio showed a distinctive pattern characterized by a sequence of three distinct periods that repeated from one year to another, and which suggested that a behavioural component influences the proportion of sex in adult specimens during reproductive and non-reproductive periods.
Biology and Ecology of Freshwater Decapods of Southern South America
P. COLLINS1,2,3, V. WILLINER1,4 & F. GIRI1,4
1Instituto Nacional de Limnología, (CONICET-UNL), Ciudad Universitaria, Pje. El Pozo s/n, CP 3000, Santa
Fe, Argentina. 2Facultad de Bioquímica y Ciencias Biológicas (UNL). 3Facultad de Ciencia y Tecnología (UADER). 4Facultad de Humanidades y Ciencias (UNL). Santa Fe, Argentina.
The decapod fauna in southern of South America (Atlantic slope) is characterized by species of five families: Sergestidae, Palaemonidae, Parastacidae, Aeglidae, and Trichodactylidae. Some species, genus and/or family are endemic, showing a strong relation with the geo-climatic history of the continent and the hydrography. The diversity, and species distribution is the product of millions of years of evolution, together with the strong relation of different geological and hydrological events that occurred in South America. Instability is a constant in this land, frostbite, heat, flooding, drought, low and high salt concentration, pH change are any of the conditions that governed the different systems. The aim of this presentation is to give a synthesis of the work about the biology and ecology of continental
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decapods in this region of the world. Prawns live in ponds and rivers and are associated to aquatic vegetation or to specific benthos communities, crabs below rocks, in caves, on the bottom and among vegetation, pseudo-crabs below rocks and crayfish in caves or below rocks. In different works, we discussed the growth and their relation with abiotic factors, due to some species of prawns that have populations that live in environment in where the conductivity oscillates between 20.5 and 5600 uhms/cm2 (e.g. Ibera, Salado River), temperature oscillates between 1 to 44 °C (mountain rivers, rivers with floodplain), the pH between 6.1 to 8.25 and the dissolved oxygen vary between 2 to 12 mg/l. The osmoregulation is a principal factor that permits that the individuals can inhabit these systems, and become more independent of osmotic relations. Some species of crabs burrow into the bed of rivers and lakes and by this maintain the humidity when the rivers or ponds are dry during certain times of the year. We observed that the reproduction has similarities in all groups, the seasonality of the events, diminution of egg numbers, the ecclosion in late stages are some of these. Moreover, the parental care or relation between juvenile and mother during a restricted period occurs in brachyurans, and anomurans. Another subject is the interaction within the systems, directing the food matter cycle and energy flux towards different communities that characterize the freshwater environments. The feeding activities vary with the different rhythms that govern the ecosystems. This causes qualitative and quantitative changes in the food chains. The decapod crustaceans are an important and interesting group for understanding the trophic webs of aquatic environments, because of their high density and nutritional quality. The dynamics of decapods in the food web and communities is regulated by the rhythms of exogenous factors such as abiotic (e.g. flood pulse, temperature, seasonality, light hours, conductivity, pH) and biotic parameters (presence of predators, competition, trophic situation). Moreover, the activities are coupled to endogenous rhythms of each species (e.g. molting, reproduction, nutrition requirement). All these rhythms that influence trophic relationships corresponding to the evolutionary interaction for many years between environment and species. Freshwater prawns and crabs are considered to be not only predators but also prey, being important elements in the food chain. These crustaceans take part in the matter-of energy exchange between aquatic and terrestrial systems. The information obtained shows that the hydrological regime, and the connectivity degree among different environments influence the refuge and food availability modified the intra- and interspecific relationships.
An Overview of the Afrotropical Freshwater Crab Fauna: Diversity, Evolution, Biogeography, and Conservation
NEIL CUMBERLIDGE
Chair, Freshwater Crab and Crayfish Specialist Group,IUCN Species Survival Commission
The Afrotropical zone includes 137 species of freshwater crabs in 18 genera that belong to two families: the Potamonautidae and Potamidae. The Afrotropical freshwater crabs are found throughout sub-Saharan Africa and on the islands of the western Indian Ocean
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(Socotra, the Seychelles, and Madagascar). The Afrotropical freshwater crab fauna is highly endemic at the family, genus, and species levels and is distinctly regional in character, with distinctive species assemblages in the west, east, central, southern, Madagascan, Seychellian, and Socotran regions. The total taxonomic diversity of the Afrotropical region (18 genera, 137 species, 2 families) is markedly lower than that seen in the freshwater crab faunas of the Neotropical (50 genera, 298 species, 2 families) and Oriental/Palaearctic (154 genera, 849 species, 2 families) regions. The evolutionary relationships of the Afrotropical freshwater crabs indicate at least three different lineages within the region. The recent IUCN Red List conservation assessment found 20% of the Afrotropical species to be threatened, with another 20% of species biologically unknown (data deficient), making the number of threatened species likely to be an undercount. Threats from habitat destruction and pollution are a major concern due to the rapidly growing economy and massive developments taking place in the Afrotropical region. There is a need for more species exploration and for the development of a conservation strategy for Africa and Madagascar’s threatened (and potentially threatened) endemic freshwater crab species.
The Virtual Library of Biology (vifabio): Subject Portal for Biodiversity and Other Facets of Biology
JUDITH DÄHNE, GERWIN KASPEREK, & JASHAR REXHEPI
University Library Johann Christian Senckenberg, Bockenheimer Landstrasse 134-138,
60325 Frankfurt am Main, Germany
The Virtual Library of Biology (vifabio, www.vifabio.de/?lang=en) combines high-
quality scientific sources from libraries, article databases and the Internet. vifabio’s goal is to cover biology in its entire breadth and to meet the different requirements of users demanding a good library service: not only molecular biologists, who want to search the latest journals, but also taxonomists, who require species descriptions from the 18th century, should be able to find what they need.
The central element of vifabio is the Virtual Catalogue: multiple library catalogues with important biological collections, bibliographic data of the Biodiversity Heritage Library and Animalbase, several article databases and the vifabio Internet Guide can be searched with a single query. Links to the electronic journals library and delivery services simplify access to full-texts or hard copies. In the presentation examples showing use cases of freshwater crab carciniologists will be given. Modules like the Internet Guide or the Database Guide open up further research options. vifabio offers additional services such as lists of new titles and subject dossiers e.g. “Internet sources for the International Year of Biodiversity” (www.vifabio.de/iyb2010/?lang=en).
vifabio is a project of the University Library, Frankfurt am Main (Germany), in conjunction with further libraries and biological organisations. vifabio is on the Web since 2007 – worldwide and free of charge.
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Demographic History and Colonization of the Seychelles by a Freshwater Crab Species
SAVEL REGAN DANIELS
Stellenbosch University, Merriman Avenue, 7602 Stellenbosch, South Africa
In the present study, the endemic monotypic freshwater crab species Seychellum alluaudi is used to examine the initial colonization route of the species and its subsequent evolutionary history among in the Seychelles Archipelago. Five major granitic islands including Mahé, Praslin, Silhouette, La Digue and Frégate were sampled. Two partial mtDNA fragments, 16S rRNA and cytochrome oxidase subunit I (COI) was sequenced for 83 specimens of Seychellum alluaudi collected from 15 localities on the five granitic islands. Evolutionary relationships were inferred with the use of Maximum Likelihood, Maximum Parsimony, Minimum Evolution and Bayesian inferences, using bootstrap and posterior probabilities to determine statistical robustness of the clades. Analyses of molecular variance (AMOVA) was used to examine genetic variation among and within clades detected from the phylogenetic analyses, while mismatch distributions were also undertaken for each of the observed clades. A haplotype network was constructed using TCS for the entire data set, while a Nested Clade Analyses (NCA) was performed on a subset of the samples in the largest and most well sample clade, to examine the factors causal to the phylogeographic patterning. Divergence time dating using PAML was employed to date the colonization of the species on the granitic island. Phylogenetic analyses of the combined mtDNA data for the 83 specimens and retrieved a monophyletic Seychellum alluaudi group comprised of three statistically well supported clades. Clade one was exclusive to Silhouette Island and basal, clade two included samples from Praslin Island sister to samples from La Digue Island, while clade three comprised samples from Mahé Island sister to samples from Frégate Island. Within Mahé Island the largest granitic island, substantial phylogeographic substructure was evident within the island and three additional subgroups were detected that included a southern, central and northern cluster. Divergence time estimations predate the Plio/Pleistocene sea level regressions and indicate a mid Miocene divergence between the three clades evident within S. alluaudi. Furthermore divergence time estimation suggest the granitic islands were first colonized as a result of transoceanic dispersal from East Africa, a result that is corroborated by paleo oceanographic modelling. While the predominant oceanic current is currently in a western direction, recent counter current over water-mediated dispersal between Mahé and Frégate Islands suggest that current exchange have also changed in an easterly direction. Three distinct allospecies are present within Seychellum alluaudi on the granitic islands / clades of the Seychelles underscoring the importance of systematic studies in biogeographic studies.
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Phylogeography and Genetic Diversity of Neotropical Freshwater Shrimp of the Family Atyidae (Decapoda, Caridea)
SUSANNE FÜSSEL1, LUCAS TORATI2, FERNANDO L.M. MANTELATTO2 & CHRISTOPH D. SCHUBART1
1Fakultät für Biologie I, Universität Regensburg, Regensburg, Deutschland.
2University of São Paulo (USP), Brazil
Freshwater shrimp belong to eight families within the Caridea, numerically dominated
by the Atyidae (359 species), an old group of decapod shrimp with highly diverse morphological forms, comprising a wide distribution on almost all continents and mostly occurring in freshwaters. They can be characterized by their unique feeding chelipeds equipped with complex brushes on the first and second pereiopods which are used for a filtering or brushing feeding mode. The Atyidae are mostly tropical to subtropical species with few representatives in the Neotropics. In the Caribbean they are particularly diverse with genera occurring in surface rivers, i.e. Micratya, Jonga (Caribbean endemics), Atya and Potimirim (also in South America), and one subterranean genus (Typhlatya). Certain atyid species, such as P. americana and A. lanipes are restricted to the Greater Antilles.
The present study investigates intraspecific diversity of P. potimirim from Brazil and the Caribbean in order to reconstruct the geographical distribution and genetic divergence among populations and to estimate the gene flow potential. Intraspecific comparisons are carried out with DNA sequences of the mitochondrial Cox1 gene, while 16s ribosomal mtDNA and histone 3 nuclear DNA is used for species identification and higher level phylogenetics. Our results indicate the existence of two currently undescribed cryptic species within Micratya and Potimirim.
Morphology and Molecular Biology of Freshwater Decapod Populations in
a Biogeographicalical Context from Argentina, South America
F. GIRI, V. WILLINER, P. A. COLLINS, E. C. RUEDA, P. AMAVET, P. GALARZA & G. OJEDA
INALI (CONICET-UNL). Facultad de Humanidades y Ciencias (UNL).
Departamento Ciencias Naturales (FHUC-UNL)
In Argentina freshwater crustaceans decapods are grouped into 4 families: Sergestidae,
Palaemonidae, Parastacidae, Aeglidae, Trichodactylidae. The diversity and distribution of these families is the results of evolution where intrinsic and/or extrinsic factors have “acted”.
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This work is presented as a synthesis of morphology and molecular studies in a biogeographical context of different taxa to elucidate the actual evolutionary situation. All these aspects continued being studied (morphological) and new (molecular) evidences are added with the objective of finding new pieces of the puzzle concerning the evolution of the freshwater decapods. The geometric morphometrics is a relatively new tool to study shape and size. This technique combines the geometry, the statistics and the biology, allowing the traditional methods based on distances and measures to be replaced by geometric approaches. The analysis of the populations genetic structure has become an useful tool since the existent genetic variability is related to the dynamics of ecological and behavioral variables in wild populations. The measurement of variation at DNA level may allow us to predict the behavior of local populations over time since a considerable level of variation increases the ability of the species to adapt to environmental changes. Populations of Aegla platensis, A. scamosa, A. riolimayana, A. uruguayana, A. neuquensis, and A. affinis (Family Aeglidae) and Trichodactylus borellinauns and T. kensleyii (Family Trichodactylidae) were studied. The geometric morphometrics approach was carried out, exclusively, using landmarks and semilandmarks. Then, the analysis of the shape was carried out principally using the TPS software package. The selection of the landmarks was different for each species, so that different configurations of landmarks and semilandmarks were explored and used. For each analysis relative warps were obtained in an exploratory way. Finally the analysis of shapes of the cephalothorax was conducted as a whole and for some species of Aeglidae considering it as a modular structure. The statistical methods used were uni- and multivariate. It is well known that a population can present an unique gene combination and the genetic structure of a set of reproductively isolated populations can mutually diverge. In this way we have analyzed the genetic structure of different populations of Aegla singularis and Aegla uruguayana. The genetic variation between populations was assessed by using RAPD analysis. The results showed that the populations exhibited different shape patterns. A. scamosa, A. riolimayana and A. uruguayana presents clinal patterns while in A. platensis this pattern was not observed in relation to the distribution of populations. A. riolimayana and A. neuquensis populations presented distributional patterns associated to pseudo-crabs inhabiting rivers vs. those living in lakes. Regarding crabs, T. borellinauns presents different shapes considering a metapopulation structure and environmental parameters in the ventral region but not in the dorsal. T. kensleyii specimens from different basins did not exhibit statistical differences in shape. Molecular analyses considering two populations of A. singularis (from the different basins) showed no population differentiation. However, high levels of polymorphism were found in one population (Pesiguero stream) unlike an other (Coaty stream). The same analysis was performed considering 3 populations of A. uruguayana from the same metapopulation. In this case, we found significant differentiation among populations. Genetic distance is possibly due to, a clinal pattern related to colonization events. In this context, through interpretation of data which have long been working together with the incorporation of new tools we began to reinterprete the evolutionary aspects of the freshwater decapods from Argentina and South America.
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Global Trends in the Description of Freshwater Decapoda, 1758-2010
SAMMY DE GRAVE1, DARREN C. J. YEO2, CELIO MAGALHAES3, NEIL CUMBERLIDGE4, KEITH A. CRANDALL5 & PETER K.L. NG2
1Oxford University Museum of Natural History, Parks Road, Oxford OX1 3PW, United Kingdom.
2Department of Biological Science, National University of Singapore, 14 Science Drive 4, Singapore 117543. 3Instituto Nacional de Pesquisas da Amazonia, Coordenação de Pesquisas em Biologia Aquatica,
Caixa Postal 478, Manaus, Brasil. 4Department of Biology, Northern Michigan University, Marquette, Michigan 49855, USA.
5Department of Biology, Brigham Young University, 401 WIDB, Provo, UT 84602, USA
Species descriptions for the 2845 species of freshwater Decapoda (20% of global
diversity in Decapoda) named during the 252 year interval from 1758 through to 2010 are analysed in regard to species descriptions per year as well as cumulative discovery curves. The data are analysed on a global scale, as well as for seven major zoogeographical regions and are further broken down for Caridea, Brachyura and Astacidea.
The results reveal that the taxonomic inventory has accumulated at a progressively faster rate over time, through a combination of episodic bursts of activity of several workers, often spanning decades, as well as a steady increase of descriptions by numerous other authors. Peaks of high activity can be clearly linked to several key workers, as well as the appearance of large monographs. These are often followed by periods of relative inactivity.
When examined at the level of individual zoogeographic regions, the accumulation of taxonomic knowledge is particularly contingent upon the productivity of a few regional experts. Although for some taxa, the accumulation curves flatten out (for instance Palearctic crayfish) thus demonstrating near completeness of the inventory, the majority of accumulation curves in other zoogeographical regions as well as for individual taxa, demonstrate that we are some way off completing a full biodiversity inventory of the world’s freshwater Decapoda.
Molecular and Morphological Evidence for Allopatric Differentiation in Potamon persicum at Different Time Scales
ALIREZA KEIKHOSRAVI & CHRISTOPH D. SCHUBART
Fakultät für Biologie I, Universität Regensburg, 93040 Regensburg, Deutschland
Biodiversity assessment is a key instrument to understand relationships between diversity and ecosystems, especially in times of climate change and habitat destruction. To uncover the real biodiversity, taxonomic problems in species complexes and delimitations
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need to be clarified. One of the key processes driving freshwater crab diversification is allopatric differentiation resulting from geographic isolation. It has been shown that morphological differences among some species of Potamon of the family Potamidae are not always reliable and do not necessarily reflect actual species boundaries. Therefore using genetic information in parallel with morphological techniques is an accurate way for improving this. The current study focuses on intraspecific differentiation among populations of Potamon persicum, a species with a wide distribution in Iran, with molecular and morphological methods to understand initial steps of regional differentiation.
For reconstruction of phylogenetic relationships among selected populations, two different mitochondrial regions markers (16S_NDH1 and Cox1) were sequenced. The results suggest that some populations of Potamon persicum are more divergent than others and do deserve recognition as full species. Our results also show that P. persicum radiated recently, over time becoming restricted to different watersheds.
Issues in the Phylogeny and Phylogeography of Selected American Freshwater Prawns (Caridea: Palaemonidae)
ALEXANDER MEE-WOONG KIM
Harvard University, 4661 Buckhorn Ridge, 22030, Fairfax, Virginia, USA
Though the Neotropics are an important secondary center of freshwater diversity for the
family Palaemonidae, intrageneric relationships between the freshwater prawns of this region and those of the Old World remain poorly characterized. Furthermore – while the importance of marine larval dispersal for Macrobrachium in particular is attested to by the geographic breadth of many species’ distributions (often including oceanic islands) and the existence of amphi-Atlantic sister species – the degree of connectedness between populations of very wide-ranging amphidromous species represents another point of contention. Through multilocus genetic analysis, we investigate inter- as well as intraspecific relationships amongst a number of American freshwater Palaemonidae (mostly Atlanto-Pacific sister species of the genus Macrobrachium), with a special focus on vicariant speciation following the formation of the Isthmus of Panama. In doing so, we attempt both to situate New World Macrobrachium in the context of inter-continental dispersal and to examine genetic structure at much finer geographic scales. Comment is also made on the systematic positions and phylogenetic affinities of a number of poorly sampled taxa, including a subterranean North American species and the broadly distributed M. ohione.
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Island Radiations and Geology
1Dept. of Ecology and Evolution, Goethe University, Frankfurt am Main
5Dept. of Biological Science, National University of Singapore, Singapore
Primary freshwater crabs are generally considered as good biogeographic indicators with a high potential for endemicity. Here I present several examples that support this view: (1) Disruption of gene flow between populations and subsequent speciation caused by a narrow marine barrier during the Early Pleistocene (Eastern Mediterranean area); (2) origin and early evolution of the Asian family Gecarcinucidae, (3) dispersal from the Sunda shelf into Wallacea despite the presumed absence of terrestrial connections; (4) island radiations and dispersal of the sundaic genus Parathelphusa H. Milne Edwards 1853; (5) preliminary data on Neotropic freshwater crabs.
Freshwater Crayfish of Mexico: Taxonomy, Biogeography, Phylogeny and Conservation Status
MARILÚ LÓPEZ MEJÍA
Laboratorio Biología Evolutiva y Genética de Poblaciones, Universidad de Quintana Roo,
Unidad Académica Cozumel, Av. Andrés Quintana Roo con calle 110 s/n, Cozumel 77600, Q. Roo, México
Mexican crayfish inhabit freshwater and salt marsh waters. They have been subjects of a number of zoological and biomedical studies. Not long ago, the study of the Mexican crayfish was focused on taxonomical analysis and new species descriptions. However, recent studies have widened the knowledge about these crustaceans in terms of their morphological and molecular phylogenetic relationships, distribution and diversification. This study presents the status of Mexican crayfish showing the current number of species, increased distributional ranges, phylogenetic relationships and the efforts for their conservation.
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The Distribution of Freshwater Decapods on Papaloapan River, México
LUIS M. MEJIA-ORTÍZ
Lab. De Biospeleology & Carcinology; Universidad de Quintana Roo, Campus Cozumel.
The Papaloapan river, an important basin in Mexico, is located on the Gulf of Mexico
slope and includes different states in Mexico (Veracruz, Oaxaca & Puebla). In this ecosystem there are several areas inhabited by different crustaceans groups. The freshwater decapods in this system comprise shrimps and crabs. We made several surveys in the area in order to identify the different taxa and their distributions within the basin. The decapods were sampled using traps with bait and also we collected by hand. We found exclusively freshwater crabs of the families Pseudothelphusidae and Trichodactylidae; also we registered in the estuarine zone crabs belonging to the Ocypodidae; Portunidae; Grapsidae; Xanthidae. Of the shrimps we collected several species of Palaemonidae; Atyidae; Alpheidae and also crayfishes of the family Cambaridae. It is evident that there are some areas where we can find Natantia and Reptantia together, normally we collected one group of decapods (shrimps, crabs or crayfish) using microhabitats but with different role in the benthic rivers and streams. We discuss the distribution of these species and their roles and possible competition among them.
The Freshwater Crabs of Lake Kivu with Comparisons to the Faunas of Other Central African Rift Valley Lakes
(Decapoda: Brachyura: Potamonautidae)
Department of Biology, Northern Michigan University, Marquette, MI USA
We present here the results of a taxonomic revision of the freshwater crabs
(Potamonautidae) of Lake Kivu, a volcanic barrier in the East African Rift Valley that lies partly in the Democratic Republic of the Congo and partly in Rwanda. The study revealed four species of freshwater crabs from Lake Kivu itself: Potamonautes idjwiensis (CHACE, 1942), P. mutandensis (CHACE, 1942), P. lirrangensis (RATHBUN, 1904), and P. bourgaulti, sp. nov. Four additional species were identified as belonging to the drainage area of Lake Kivu: P. gonocristatus (BOTT, 1955), P. minor (BOTT, 1955), P. perparvus (RATHBUN, 1921), and P. semilunaris (BOTT, 1955). The taxonomic status and distribution of each species is discussed, and the freshwater crab fauna of Kivu is compared to that of the other African great lakes.
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Assessing Environmental Impacts of Shrimp Effluent Expressed by Biological Indicators
MARYAM MODANLOW & HAMED AZARBAD
Faculty of Natural Resources, Karaj, Iran
Aquaculture is a rapidly expanding industry, and its effluent can be a major source of pollution in marine ecosystems. Environmental studies into the effects of shrimp aquaculture are limited and have mostly focused on in-pond water quality, with little research conducted into the ecological impacts of wastewater on receiving waters. Shrimp pond effluent has higher concentrations of suspended solids and phytoplankton, but lower concentrations of nutrients than sewage effluent. Dissolved nutrients in shrimp effluent are predominantly NH4, whereas sewage effluent is proportionally higher in NO3 and PO4. These differences may have a considerable impact on the fate of organisms in the receiving waters when effluent is released into shallow tidal estuaries. Both sewage and aquaculture effluent can be discharged intermittently, resulting in large dial fluctuations in water quality. Difficulties in monitoring these variable discharges can be overcome by the use of biological indicators, which integrate the impacts of these effluents over time. Unlike traditional chemical analyses of water column nutrients, these biological indicators reflect the availability of biologically available nutrients which provides more ecologically meaningful information. The aims of this study were to assess the influences on the receiving environment of wastewater discharges to a shallow estuarine system. Changes in receiving water and sediment quality analyses were compared with biological impacts measured as a consequence of shrimp farm and sewage effluent discharges. Water quality and sediment parameters measured included chlorophyll a, total suspended solids, volatile suspended solids, dissolved nutrients, salinity, and sediment organic content. Biological indicator monitoring consisted of analysis of amino acid composition, tissue nitrogen (N) content and stable isotope ratio of nitrogen in sea grasses, mangroves and macro algae.
Distribution of Native and Alien Freshwater Decapod Crustacean Species in the South of Iraq
MURTADA D. NASER, MALIK H. ALI & AMAAL G. YASSER
Department of Marine Biology, Marine Science Centre, University of Basrah, Basrah, Iraq
Six species of freshwater decapod crustacean species have been found in the Shatt Al- Arab waterways in southern Iraq. Four are native (Atyaephyra desmaresti mesopotamica,
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Caridina babaulti basrensis, Chiromantes boulengeri and Potamon mesopotamicum) and two are alien (Macrobrachium nipponense and Eriocheir sinensis). Atyaephyra desmaresti mesopotamica and C. babaulti basrensis are the most widespread species in the south of Iraq. The distribution of Ch. boulengeri and P. mesopotamicum is restricted to the upper stream of Shatt Al-Arab river with salinity less than 0.7 ppt, both species are missed at the main stream south of Shatt Al-Arab where the salinity range to be 1.2 to 2.5 ppt. The presence of alien species is an increasing problem: M. nipponense was found at new sites, reaching the upper part of Shatt Al-Arab while E. sinensis recorded in Shatt Al-Basrah in 2006, extending its distribution recently to the upper stretches of the Shatt Al-Arab river.
Genetic Diversity of Freshwater Crabs of the Genus Ptychophallus (Brachyura: Pseudothelphusidae)
in the Cordillera Central in Costa Rica
THEO POETTINGER & CHRISTOPH D. SCHUBART
Fakultät für Biologie I, Universität Regensburg, 93040 Regensburg, Germany
For the identification of the genetic-geographical structure and the documentation of possible cryptic endemism, the DNA from the mitochondrial CO1 and 16S rRNA genes of 65 Costa Rican freshwater crabs of the genus Ptychophallus was sequenced. 62 animals of the species Ptychophallus montanus were collected from the upper regions of the Río Barranca river system (Alajuela/Puntarenas) in Costa Rica and examined and compared molecularly- genetically. For phylogenetic reconstructions, additionally numerous 16S-sequences were obtained and evaluated from further neotropical fresh water crabs of the family Pseudothelphusidae. The analysis of the CO1-region showed an amazing uniformity of the individual sequences, with exception of a population from a small brook in the proximity of the Quebrada Palmital (N 10° 09,320´ W 84° 37,150´), which very probably represents another species. In addition, with the sequences from the 16S rRNA a consistent partitioning of the individuals of the Río Barranca into two genetically different subpopulations became evident based on a single point mutation. The possibly endemic character of the population at the Quebrada Palmital would have to be further examined, before possible preventive measures are postulated for these waters.
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Differences in Population Genetic Structure of Freshwater Crabs (Brachyura: Pseudothelphusidae) from two Caribbean Islands
NICOLE T. RIVERA & CHRISTOPH D. SCHUBART
Fakultät für Biologie I, Universität Regensburg, 93040 Regensburg, Germany
The Greater Antilles are classified as a biodiversity hotspot due to their high species richness and increased endemism. Within islands, isolated freshwater systems can be considered insular systems, in which morphological convergence or stasis may result in cryptic speciation. Freshwater crabs are thus great model organisms to investigate the biodiversity of the Greater Antilles or other islands. Nevertheless, the three islands Puerto Rico, Hispaniola and Cuba only exhibit one to four described, endemic species of the genus Epilobocera of the family Pseudothelphusidae. The Pseudothelphusidae represent a family of real freshwater crabs inhabiting mostly mountain streams in the tropical belt of the Neotropics. The genus Epilobocera is said to be early derived within the Pseudothelphusidae, which may suggest that the Greater Antilles are the cradle of these freshwater crabs.
In this study we compared the phylogeography of two species of the genus Epilobocera: E. haytensis from Hispaniola and E. sinuatifrons from Puerto Rico by analyzing the mitochondrial gene NADH 1 of over 300 individuals from both islands. The results show poorly structured intraspecific diversity and thus widespread gene flow for both species and lack of cryptic speciation. Consequently these species do not seem to be restricted to their watersheds and their distribution is not limited by terrestrial barriers. This is supported by the presence of a perforated area, a so-called “pseudolung” which is an obvious adaptation to a semi-terrestrial life. It can be recognized that most differences in population genetic structure are caused through isolation by distance.
Phylogeography and Postglacial Dispersion of the Noble Crayfish
(Astacus astacus)
Institute for Environmental Sciences, University Koblenz-Landau, 76829 Landau, Germany
Severe climatic oscillations during the Pleistocene resulted in great changes in species distribution areas characterised by contractions and expansion of geographical ranges. Southern Europe, especially the Iberic peninsula, Italy and the Balkans, served as a refuge during cold periods for many animal groups. Under temperate conditions a northward spread
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of many species was possible. In general, the centres of range expansions or glacial refuges are characterized by higher levels of population differentiation and more recently colonised areas by a rather homogenous gene pool.
To obtain a picture of large-scale differences and to reconstruct the phylogeography of the endangered European crayfish species Astacus astacus, we analysed partial sequences of two mitochondrial genes (16s rRNA, COI) from specimens of the main European river basins. Among 60 crayfish stocks and 300 specimens 12 haplotypes of 16s rRNA and 25 haplotypes of COI could be identified. One haplotype of each gene was dominant whereas all other haplotypes were less frequent in the studied populations. Resulting phylogeographical patterns were in accordance with the following expectations: 1. A glacial refuge in the Balkans served as source for postglacial recolonisation of central
Europe. 2. A north- and westward spread after the last ice age took place along the Danube basin. 3. Due to repeated founder effects, haplotype diversity was reduced from southern to northern
Europe. Furthermore, we assume a second refuge, but a more detailed study is needed to
confirm this assumption. An additional attempt to identify autochthonous noble crayfish populations in central
Europe turned out to be difficult due to a high rate of artificial translocation of stocks for hundreds of years.
Testicular Yellow Pigments in a Freshwater Crab: an Ultrastructure Study
A. SHYLA SUGANTHI1, G. ANILKUMAR2 & V. GANAPIRIYA3
1Department of Zoology, Holy Cross College, Nagercoil, Tamil Nadu, India.
2School of Biotechnology, VIT University, Vellore, Tamil Nadu, India. 3Department of Zoology, Khadir Mohideen College, Pattukottai, Tamil Nadu, India
The reproductive system in the freshwater crab Parasesarma sp. appears lemon-yellow in colour all the way through, from the testicular lobes up to the ejaculatory duct, excepting the accessory glands that appear milky white in colour. Smear preparations of the seminal plasma show the presence of a yellow hue, apparently due to the presence of pigmentation. Our histological studies reveal that the colouration seen in the seminal plasma is caused by the presence of crystalline structures that are secreted by the inner testicular lining. The epithelial lining shows the occurrence of yellow granules within its cytoplasm. As these granules reach the testicular lumen, they are supposed to be transformed into flakes which display its presence in the close proximity to the spermatocytes, spermatids and spermatozoa; rarely though, these flakes are seen also in association with the spermatogonial cells. At the anterior vas deferens (AVD), the pigments are seen aggregated into groups along with the spermatozoa. In the middle vas deferens (MVD), the pigments are encased within the
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spermatophores, seen interspersed among the spermatozoa; the pigments appear hardly in the seminal plasma. It is obvious that these structures impart yellow colouration to the semen. Under electron microscope, the spermatophores exhibit the presence of electron dense filamentous structures, apparently representing the pigments. Interestingly, the spermatozoa are also seen surrounded by a thick layer of electron dense material, possibly derived from these pigments. Existence of pigmentation, to our knowledge, has not been reported in any of the crustacean seminal plasma so far. The semen from a number of Friesian bulls, however, has been reported to be yellow and the pigment responsible for the yellow hue has been identified as riboflavin that produced a green fluorescence. The occurrence of flavins has been reported in human seminal vesicular secretions as well, the exact function of which is not clear. However, with its probable role as constituent part of the coenzymes (FAD, FMN), the riboflavin’s are believed to take part in (seminal) metabolism.
A morphological phylogeny of the family Pseudothelphusidae
JOSE LUIS VILLALOBOS & *FERNANDO ALVAREZ
Colección Nacional de Crustáceos, Instituto de Biología, Universidad Nacional Autónoma de México, Circuito exterior s/n, Cd. Universitaria, Delegación Coyoacan Apartado postal 70-153,
C. P. 04510, México, D. F., México.
Among the freshwater decapods that are distributed across America, the crabs of the family Pseudothelphusidae constitute one of the most important groups due to their distribution and diversification. More than 280 species of pseudothelphusids are now recognized, organized in 41 genera, five tribes and two subfamilies. Although the taxonomic studies on this family began early in the XIX century with the description of Thelphusa dentata LATREILLE 1825, until now there isn’t a study analyzing the phylogenetic relationships among the tribes, genera and species. A recent study on the phylogeny of the tribe Pseudothelphusini shows a paraphyletic structure. Other tribes in the subfamily Pseudothelphusinae, Hypolobocerini, Potamocarcinini and Strengerianini, that include a large diversity of morphologies of the first male gonopod, with a wide geographical distribution from southern Mexico to central South America, have not been either the subject of a phylogenetic analysis. Our study is a preliminary cladistic exercise to establish homologue characters that support the cohesion of the tribes as monophyletic taxa inside the subfamily Pseudothelphusinae. The morphological revision of the type species of each one of the 41 genera in the subfamily produced 64 characters and 248 character states. The majority of those traits were obtained from the complex gonopod morphology, and additional characters were derived from the outline of the merus of the third maxilliped and the length of the exopodite. Preliminary results show that several genera from southern Mexico and Central America are not correctly assigned to a tribe and the relationships between taxa in those areas and in northern South America need to be re-evaluated.
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Ageing in decapod crustaceans, with Particular Emphasis on Freshwater Crayfish
GÜNTER VOGT
University of Heidelberg, Germany
The Decapoda include more than 10.000 species, have maximum adult sizes of ~1 cm to 4 m, inhabit many different habitats and display a broad variety of life styles. Accordingly, they have developed many different life history and ageing patterns. Life span ranges from ~1 year in some natantian shrimps to ~100 years in the American lobster. In wild populations, age determination is quite difficult because decapods have no durable growth-ring bearing structures like bivalves or fishes that could provide exact information on their age and life- history dynamics. At present, the most reliable ageing method is determination of the lipofuscin content in specific areas of the brain, which has been shown to be superior to body size-based techniques like analysis of length-frequency data. However, precise data on longevity in decapods can only be obtained in captivity or by mark and recapture.
The Decapoda offer suitable research subjects for almost all topics of biogerontology. For instance, indeterminately growing species, which account for the majority of the decapods, show negligible senescence. Therefore, they are suitable to investigate how to escape from senescence, the age-related decline in structural and functional status. In contrast, determinately growing species like some spider crabs are suitable to study organismic, tissular and behavioural senescence in detail. All decapods can escape from mechanical senescence by moulting, which not only renews the cuticle but also enhances the efficiency of the external sense organs and the masticatory and filtering structures of the stomach. Comparison of cold adapted species from polar regions with their closest tropical relatives enables studying of the influence of temperature on longevity, and comparison of troglobionts and their epigean relatives provides information on the relationship of caloric restriction and longevity. The long-lived lobsters are suitable to search for genes promoting long life.
The clonal marbled crayfish proved particularly suitable to investigate the dependency of ageing and longevity from non-genetic factors like stochastic developmental variation, allocation of metabolic resources, damage and repair, caloric restriction and social stress. This crayfish was detected in the mid 1990s and is a parthenogenetic form of Procambarus fallax native to Florida and Georgia. It is an emerging laboratory model for development, toxicology and epigenetics that can produce up to 400 genetically identical siblings per batch. It is easily cultured, has an adult size of 4-9 cm, a generation time of 6-7 months and an average life span of 2-3 years. The marbled crayfish is also suitable to examine alterations of the epigenetic code with increasing age and to identify mechanisms that keep stem cells active until old age.
Indeterminately growing decapods are highly resistant to age-related diseases inclusive of cancer. This property is probably related to their ability to maintain stem cell activity until old age, to isolate pathologically transformed and neoplastic tissue areas by melanization and encapsulation and to effectively detoxify environmental toxicants and toxic metabolites by metallothioneins, cytochrome P450, anti-oxidative enzymes and free radical scavengers. In the protected environment of the laboratory, more than 80% of the mortality in adult marbled crayfish is attributable to unsuccessful moulting.
Knowledge on ageing in decapods is not only of academic interest but also of practical relevance. In crustacean fisheries, it helps to correctly estimate the fishery potential of wild
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populations, and in aquaculture, it is useful to optimize grow-out and reproduction strategies of highly valuable strains. Some of the ageing phenomena recorded in decapods may even have a good potential for the development of anti-ageing interventions in humans, for instance, the use of astaxanthin as a highly effective scavenger of free radicals.
Offspring Production of Freshwater Crabs from Amazon Region and Central America (Brachyura: Pseudothelphusidae)
INGO S. WEHRTMANN1,2, CÉLIO MAGALHÃES3, PATRICIO HERNÁEZ2,4,5
& FERNANDO L. MANTELATTO6
1Museo de Zoología of the Escuela de Biología, Universidad de Costa Rica, 2060 San José, Costa Rica. 2Unidad de Investigación Pesquera y Acuicultura (UNIP) of the Centro de Investigación en Ciencias
del Mar y Limnología (CIMAR), Universidad de Costa Rica, San José, Costa Rica. 3Coordenação de Pesquisas em Biologia Aquática, Instituto Nacional de Pesquisa da Amazônia, Manaus, Brasil.
4Museo del Mar, Universidad Arturo Prat, Casilla 121, Iquique, Chile. 5Program of Post Graduation on Comparative Biology – FFCLRP (USP), Brazil.
6Laboratory of Bioecology and Crustacean Systematics, Department of Biology, FFCLRP – University of São Paulo (USP), Program of Post Graduation on Comparative Biology – FFCLRP (USP),
Av. Bandeirantes – 3900, 14040-901, Ribeirão Preto, São Paulo, Brazil.
Freshwater crabs constitute an important component of the fauna of limnic environments, and thePseudothelphusidae are the most diverse of the two true freshwater crab families in the Neotropics. Considering the lack of information regarding reproductive features of neotropical freshwater crabs, we studied egg production and the presence of juveniles carried by females of two pseudothelphusids from the Amazon region (Kingsleya latifrons, K. ytupora) and one of Central America (Potamocarcinus magnus). The two Kingsleya species produced relatively few (56-114) and large eggs (1.9 – 3.7 mm), typical for species with an abbreviated or direct development. Recently-produced eggs were substantially larger in K. latifrons (mean 2.83 mm) when compared to those of K. ytupora (mean 1.87 mm); however, at the end of the embryogenesis, mean egg diameter was similar in both species. Therefore, it is assumed that hatchlings in both species should have a similar size. A brief description of attached juveniles of K. ytupora is provided. The number of eggs increased significantly with female size in both pseudothelphusids crabs; however, the mean egg number was higher in K. ytupora (80 ± 18.1 eggs) than in K. latifrons (73 ± 10.6 eggs). The number of juveniles carried by the females varied between 30 (K. ytupora) and 179 (P. magnus); two size groups of juveniles were found, which indicates that the offspring cling to their mother for a prolonged period of time. There was no significant loss of eggs and juveniles; it is assumed that parental care diminishes the loss of offspring. We compiled the available information of reproductive aspects from freshwater crabs: egg diameter was in the range of 2 and 3 mm, independent of female size and fecundity, and reported egg number varied between 9 and 417.
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On the Freshwater and Terrestrial Crabs of Pulau Natuna Besar, Indonesia
DARREN C. J. YEO1, DAISY WOWOR2 & PETER K. L. NG1
1Department of Biological Sciences, National University of Singapore.
2Museum Zoologicum Bogoriense, Indonesian Institute of Science (LIPI)
The brachyuran fauna of Pulau Natuna Besar (= Pulau Bunguran), a remote island in the
middle of the South China Sea, midway between Peninsular Malaysia and Borneo, has not been well studied, with only a single primary freshwater crab species, Balssiathelphusa natunaensis (Gecarcinucidae) recorded to date. In 2002, we conducted a survey of the inland brachyuran fauna of the island. A variety of habitats were sampled, ranging from waterfalls and freshwater hill streams to the forest floor to coastal mangroves. We document the freshwater and terrestrial crabs encountered, with notes on their habitat and behavior. Our study raises the number of species known from the island to seven, as we report six new records viz., Cardisoma carnifex (Gecarcinidae), Episesarma chentongense (Sesarmidae), two new species of Sesarmidae (Geosesarma sp., Labuanium sp.), Parathelphusa maculata (Gecarcinucidae), and one new genus and species of Potamidae. The new genus and species is clearly related to Isolapotamon and Allopotamon but differs in a number of unusual external and gonopod features. We also document the re-discovery of Balssiathelphusa natunaensis, previously only known from its original description by RICHARD BOTT in 1970.
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Poster presentations
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Colección Nacional de Crustáceos, Instituto de Biología, Universidad Nacional Autónoma de México, Circuito exterior s/n, Cd. Universitaria, Delegación Coyoacan Apartado postal 70-153,
C. P. 04510, México, D. F., México.
The crayfish of the family Cambaridae area widely distributed decapod group in Mexico. Many of the 57 recognized species cover very small distribution areas, often restricted to one or two localities. Few are the species that are widely distributed, such as Cambarellus montezumae in central Mexico, or Procambarus llamasi from the Yucatán peninsula. We analyzed a data base containing more than 1400 records of all the species present in Mexico. The country was divided in cells of 1º of latitude by 1º of longitude to map all the records. Following Crisp et al. (2001) proposal we compare species richness in each cell with a simple index of endemism and then with a corrected one where species richness has been considered. The results show that the corrected endemism index is relatively independent of species richness in three regions of Mexico and that high endemism areas are not necessarily the same as the high diversity areas. We discuss what conservation policies can be derived from these results in the light of the rapid deterioration of freshwater habitats throughout Mexico. Morphological Staging of Maturation of the Freshwater Shrimp Atyaephyra
desmarestii (MILLET, 1831) s.l. (Decapoda: Caridea: Atyidae)
CHRYSSA ANASTASIADOU & IOANNIS D. LEONARDOS
Laboratory of Zoology, Department of Biological Applications and Technology, University of Ioannina, 451 10, Ioannina, Greece.
Atyaephyra desmarestii (MILLET, 1831) s.l. is a freshwater shrimp, which has a wide distribution in Europe, North Africa, and the Middle East. Species populations from different areas of its zoogeographical distribution are under taxonomic investigation. Additionally, the bionomic studies on the species provide us important and useful information on the reproduction, larval development and population dynamics. Under this framework, new and detailed information on the morphological staging of the different phases for juveniles, immature, female and male mature individuals of A. desmarestii s.l. is given for the first time. Sampling was carried out in Louros River, near Flaboura (39
ο 3.745 Ν, 20
ο 46.312 Ε, NW
Greece). Specimens of A. desmarestii s.l. were collected by means of a hand net with a frame of 30 cm X 35 cm and a mesh size of 2 mm and preserved in situ in 4% formalin solution. The sex was identified through stereo-microscopic inspection of the first and second pairs of pleopods. The study of the collected material revealed eight phases; two phases for juveniles, three phases for immature and three phases for the mature male and female specimens. In the first and second juvenile phases there is no sex discrimination. The main morphological discriminative characters of these phases are the rostral formula and antennules’ formation. Secondary discriminative characters are the setation of antennae and appendix interna length of the 2
nd pleopod. In the next three immature phases, the sex discrimination is possible. The
main discriminative characters of these phases are the rostral formula and the sexual organs’ morphology. Finally, the last three phases conclude the mature male and female specimens. The main discriminative characters of these phases are the number of aesthetascs and pereiopods’ setation.
Ecological Impacts of Shrimp Effluent in Coastal Water
H. AZARBAD, M. MODANLOW, A. JAVANSHIR & M. SHAPOORI
Department of Fisheries and Environmental Sciences,University of Tehran, Faculty of Natural Resources, Karaj, Iran
Intensive shrimp aquaculture systems rely on high protein feed pellets to produce high
rates of growth, but a large proportion of the pellets are not assimilated by the shrimps. Approximately 10% of the feed is dissolved and 15% remains uneaten. The remaining 75% is ingested, but 50% is excreted as metabolic waste, producing large amounts of gaseous, dissolved and particulate waste. Subsequently, the effluent contains elevated concentrations of dissolved nutrients (primarily ammonia), plankton and other suspended solids. The dissolved nutrients and organic material in shrimp ponds stimulate rapid growth of bacteria, phytoplankton, and zooplankton. These untreated wastes are usually discharged directly into the environment, where they may enhance eutrophication, organic enrichment and turbidity of the local waterways. Concerns about the possible adverse impacts of aquaculture discharge have become a risk factor for the industry. This has prompted efforts to develop cost-effective methods of effluent treatment. The use of filter feeding bivalves such as oysters to consume phytoplankton, zooplankton, and bacteria, and macroalgae to assimilate the remaining dissolved nutrients may prove to be an efficient and economically viable alternative for improving the water quality of shrimp farm discharges. In addition to filtering organic food particles, oysters can also improve the quality of pond effluent by reducing the concentration of inorganic suspended solids.
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Biogeographic Range of the Genera Potamon and Himalayapotamon - molecular and morphological aspects
DIRK BRANDIS
Zoologisches Museum der Christian-Albrechts-Universität zu Kiel, Hegewischstrasse 3, 24105 Kiel, Germany
The freshwater-crab genus Potamon is widely distributed in south-eastern Europe and the Middle East. In the Himalayas it is replaced by the genus Himalayapotamon. The eastern distributional margin of Potamon as well as the western distributional margins of Himalayapotamon remained unclear due to taxonomical problems and a poorly known crab fauna from the very western slopes of the Himalayas. A careful re-examination of museum material and new collections from Pakistan, Nepal and Bhutan now allow a more detailed picture of the distribution of Potamon and Himalayapotamon and the clarifying of relevant biogeographic margins.
Progress on the Assessment of the Taxonomic Status of the Circum-
Mediterranean Genus Atyaephyra DE BRITO CAPELLO, 1867 (Decapoda: Atyidae)
M. CHRISTODOULOU1, A. KOUKOURAS1 & M. THESSALOU-LEGAKI2
1Department of Zoology, School of Biology, Faculty of Sciences, Aristoteleio University of Thessaloniki, 541 24
Thessaloniki, Greece. 2Department of Zoology-Marine Biology, School of Biology, Faculty of Sciences,
National and Kapodistrian University of Athens, 15784, Athens, Greece.
A review of older (e.g., HOLTHUIS, 1961) and recent studies (ANASTASIADOU et al.,
2006 2008) indicates that the taxonomic status of the circum-Mediterranean genus Atyaephyra is still confusing and uncertain. Older and recent taxa already assigned to the genus are inadequately described and characterised by overlapping distinguishing features.
In order to clarify the taxonomic status of the genus Atyaephyra an extensive study of numerous adult specimens from many different localities of Europe and the circum- Mediterranean region is currently in progress. In all these specimens all main morphological features are being examined and compared.
Based on the analysis that has been carried out so far, it has been ascertained that the genus Atyaephyra includes species that have evolved only recently (partly cryptic). Furthermore, the analysis of the main morphological features has revealed new, non- overlapping or partly overlapping distinguishing features that can be used to distinguish the specimens from different populations. Based on these features, the following six different taxa can be distinguished: Atyaephyra desmarestii (MILLET, 1831), Atyaephyra n.sp. 1, Atyaephyra
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n.sp. 2, Atyaephyra n.sp. 3, Atyaephyra n.sp. 4 and Atyaephyra desmarestii orientalis complex.
The species Atyaephyra rosiana DE BRITO CAPELLO, 1867 should be considered as a synonym of A. desmarestii (MILLET, 1831), while A. rosiana (DE BRITO CAPELLO, 1867) redescribed by ANASTASIADOU et al. (2008), should be placed as a synonym of Atyaephyra n.sp. 1.
The distinction of the six above taxa is mainly based on the following morphological features: (a) presence or absence of rostral teeth behind the orbit; (b) number of seta rows on basipodial lobe of maxilla; (c) number of spines on propodus of third maxilliped; (d) number of dorsolateral spine pairs on telson; (e) number of spines on merus of third and forth pereiopods and (f) shape of antennular lobe.
Molecular and Morphometric Diversity Following
Adaptive Radiation of Freshwater Crabs in the Malili lakes (Sulawesi, Indonesia)
FLORIAN KOLBINGER1, FABIAN HERDER2
2Kurator Ichtyologie, Zoologisches Forschungsmuseum Alexander Koenig, 53113 Bonn, Germany The Malili lakes are located in the central highlands of the Indonesian island Sulawesi.
These lakes are considered ancient limnic systems and thus a very interesting setting for studying differentiation and speciation processes. The last taxonomic revision of freshwater crabs from Sulawesi revealed the existence of five freshwater crab species (Potamoidea: Gecarcinucidae) in three genera within the three large lakes of the system, Matano, Mahalona, and Towuti. One of these species, the morphologically and ecologically well defined Nautilothelphusa zimmeri BALSS, 1933 is the only one encountered in all three lakes. Mitochondrial genetic data from the 16S rRNA and the cytochrome oxidase I gene demonstrate that two of these lake populations (from Mahalona and Towuti) are more closely related to the sympatric Parathelphusa ferruginea CHIA & NG 2006 than to their conspecifics from Lake Matano. The present study investigates the relationship of N. zimmeri and P. ferruginea based on nuclear DNA by using the amplified fragment length polymorphism (AFLP) technique. The AFLP markers allow comparison of a great amount of unlinked nuclear loci and therefore constitute an excellent tool to investigate phylogenetic relationships within species flocks. Furthermore, we are also exploring the use of geometric morphometrics to detect possible variation in carapace shape of the above mentioned populations of N. zimmeri.
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Stereoscopic 3D Documentation of Crayfish with a Simple Flatbed Scanner
VERENA KUTSCHERA1, CAROLIN HAUG1, JOACHIM T. HAUG1,
ANDREAS MAAS1, CHRISTOPH CHUCHOLL2 & DIETER WALOSZEK1
1Biosystematic Documentation, University of Ulm, Helmholtzstr. 20, 89081 Ulm, Germany. 2Fisheries Research Station, Lake Constance, Argenweg 50/1, 88085 Langenargen, Germany. & Dept.
Experimental Ecology, University of Ulm, Albert-Einstein-Allee 11, 89069 Ulm, Germany
Three-dimensional documentation of animals is often an expensive and time-consuming
procedure. We present a fast method, which is performable with a common flatbed scanner. The specimen is simply scanned two times in different positions: after the first scan the specimen is moved sidewards about 4–8 centimeters from its first position. With this, two images displaying the animal are created. These two images are, in fact, taken from two different perspectives due to the non-parallel optics of flatbed scanners. The resulting images can easily be processed into stereoscopic images. This method also works well for dissected parts of a specimen. Due to the high-resolution images produced by flatbed scanners today, this documentation technique is simple to perform, and it results in high-resolution 3D images. As an example for the applicability of this method, we documented representatives of all species of freshwater crayfish occurring in Germany, i.e., Astacus astacus, A. leptodactylus, Austropotamobius pallipes, Au. torrentium, Orconectes limosus, O. immunis, Pacifastacus leniusculus, Procambarus clarkii, and Procambarus sp. Specimens of all these species are presented in ventral and dorsal view as stereoscopic images created with a common flatbed scanner to emphasise the advantages of this documentation method.
Freshwater crabs from Costa Rica: diagnostics, geographical distribution, and a key for their identification
CÉLIO MAGALHÃES1, INGO S. WEHRTMANN2,
LUIS RÓLIER LARA3 & FERNANDO L. MANTELATTO4
1Instituto Nacional de Pesquisas da Amazônia, Caixa Postal 478, 69011-970 Manaus, AM, Brazil. 2Museo de Zoología, Escuela de Biología, Universidad de Costa Rica, 2060 San José, Costa Rica /
Unidad de Investigación Pesquera y Acuicultura (UNIP) of the Centro de Investigaciones en Ciencias del Mar y Limnología (CIMAR), Universidad de Costa Rica, 2060 San José, Costa Rica. E-mail:
3Instituto Costarricense de Electricidad-Proyecto Hidroeléctrico El Diquís. Puntarenas, Costa Rica. 4Laboratório de Bioecologia e Sistemática de Crustáceos, Departamento de Biologia – FFCLRP,
Universidade de São Paulo (USP), Av. Bandeirantes, 3900, 14.040-901 Ribeirão Preto, SP, Brazil.
The true freshwater crabs from Costa Rica are currently under study for a taxonomic review of the species. Currently, there are about 17 species recorded from the country, all
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belonging to the Pseudothelphusidae. Most of them are known from a few, scattered records, or even from one single record. Preliminary results of the reexamination of this material, including the type specimens of all species, as well as the study of the large collection from the Museo de Zoología, Universidad de Costa Rica, and from other related international collections, which comprises an abundant series of specimens recently collected in the southern region, led us to postulate that the Costa Rican pseudothelphusid fauna might be constituted by at least four genera (Achlidon SMALLEY, Allacanthos SMALLEY, Ptychophallus SMALLEY, and Potamocarcinus H. MILNE EDWARDS) with 14 valid species. The generic status of Pseudothelphusa puntarenas HOBBS must be reevaluated, and at least three species of Ptychophallus will be synonymized. A new species of the genus Allacanthos from the Puntarenas Province is currently under description. Revised diagnoses, illustrations of the species, and a key for their identification will be provided. The geographical distribution of the species is updated, based on the new material examined; moreover, we will illustrate the new distributional records for each species in Costa Rica.
Preliminary Evidences on Taxonomic Problems of the Freshwater Prawn species of the Genus Cryphiops
(Decapoda, Palaemonidae) by Molecular Information
FERNANDO L. MANTELATTO1, LEONARDO G. PILEGGI1, JOSE LUIS VILLALOBOS2 & FERNANDO ALVAREZ2
1Laboratory of Bioecology and Crustacean Systematics, Department of Biology, Faculty of Philosophy,
Sciences and Letters of Ribeirão Preto (FFCLRP), University of São Paulo (USP), Av. Bandeirantes 3900, CEP 14040-901, Ribeirão Preto (SP), Brazil.
2Colección Nacional de Crustáceos, Instituto de Biología, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70-153, Mexico 04510, D. F., Mexico
The palaemonid prawns of the genus Cryphiops DANA, 1852 are representatives of the caridean fauna and are distributed locally throughout tropical and subtropical waters of America, with five species assigned to the genus. During previous studies our analyses showed that C. (Cryphiops) caementarius and C. (Bithynops) brasiliensis are well positioned within the Macrobrachium group. Considering the lack of phylogenetic studies on the genus Cryphiops, we started a cooperative project aiming at analyzing the phylogeny of the genus based on morphological and molecular analysis. At this level of our research, the genetic divergence between Macrobrachium species and Cryphiops corroborates this inclusion; the preliminary levels of divergence ranged from 5.5 to 21.6% between Cryphiops and Macrobrachium species for mtDNA genes. Pending the inclusion of all members of this genus and other nuclear genes in our analysis, this positioning led us to reconsider the validity of the genus and a possible necessity of taxonomic rearrangement. Support: FAPESP; CNPq, CAPES
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Alien Chinese Mitten Crab (Eriocheir sinensis) in Northern Germany
THURID OTTO1,2, DIRK BRANDIS2 & GÜNTHER B. HARTL1
1Zoological Institute/Population genetics, Christian-Albrechts University, 24118 Kiel, Germany.
2Zoological Museum, Christian-Albrechts University, 24105 Kiel, Germany
The native range of the Chinese mitten crab (H. MILNE-EDWARDS 1853) (Crustacea, Decapoda, Varunidae) reaches from the eastern pacific coast of China to the Korean Peninsula. The species was likely introduced with ballast water to Continental Europe in the early 20th century. Meanwhile, Eriocheir sinensis is common in German marine and limnetic water systems and often occurs in high population densities. Mainly in Schleswig-Holstein (Northern Germany) this species is currently of particular interest, standing between the contradictory contexts of ecology and economy in a unique manner. Although several studies about some aspects of population genetics and reproductive biology of E. sinensis already exist, basic questions to the situation in Northern Germany haven’t been clarified yet. This presented project is aimed at understanding and evaluate the structure and dynamics of E. sinensis populations in the marine and limnetic water systems of Schleswig-Holstein (Northern Germany).
Genetic and Morphology Variability of Macrobrachium olfersi (Decapoda: Palaemonidae)
NATÁLIA ROSSI, LEONARDO A. PILEGGI & FERNANDO MANTELATTO
Laboratory of Bioecology and Crustacean Systematics (LBSC), Department of Biology, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto (FFCLRP), University of São Paulo (USP), Av. Bandeirantes 3900, CEP
14040-901, Ribeirão Preto (SP), Brazil.
Macrobrachium olfersi is an amphidromous freshwater shrimp, with wide geographic distribution, from the southern United States to south Brazil. This species has great morphological variation among individuals and is commonly misidentified with Macrobrachium crenulatum, M. digueti, M. faustinum, M. hancocki, M. acanthochirus and M. denticulatum. These species shows high morphological variation during ontogenesis, including the presence of morphotypes. Due to this fact, the variability of M. olfersi was investigated in order to establish its taxonomic limit. For this, we reviewed the material types, and about 100 specimens collected throughout its distribution and / or deposited in reference collections. In the review we have analyzed all the characters, highlighting: the shape of the rostrum; distribution of teeth; epistome; fourth thoracic sternite and the median process; shape
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of inferior orbit; cheliped adornments; the proportions of pereiopod articles, pre-anal carina. Our results showed a big

distribution and exploitation of the long-clawed crayfish

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