biology 320 invertebrate zoology fall 2005 chapter 19 – phylum arthropoda, subphylum crustacea
Post on 16-Dec-2015
222 Views
Preview:
TRANSCRIPT
Biology 320Biology 320Invertebrate ZoologyInvertebrate Zoology
Fall 2005Fall 2005
Chapter 19 – Phylum Arthropoda, Chapter 19 – Phylum Arthropoda,
Subphylum CrustaceaSubphylum Crustacea
Introduction to CrustaceansIntroduction to Crustaceans
42,000 species42,000 species
Crabs, shrimps, lobsters, and Crabs, shrimps, lobsters, and barnaclesbarnacles
Important ecologicallyImportant ecologically• ZooplanktonZooplankton
Mainly marine, but some FW and Mainly marine, but some FW and a few terrestrial varietiesa few terrestrial varieties
Mandibulates, along with Mandibulates, along with myriapods and insectsmyriapods and insects
Two pairs of antennaeTwo pairs of antennae
Body FormBody Form Two tagma in mostTwo tagma in most
Two pairs of antennaeTwo pairs of antennae• 11stst and 2 and 2ndnd antennae antennae
MandiblesMandibles
Two pairs of maxillaeTwo pairs of maxillae• 11stst and 2 and 2ndnd maxillae maxillae
Lateral compound Lateral compound eyeseyes• Often on eyestalksOften on eyestalks
PereopodsPereopods• Walking legsWalking legs
PleopodsPleopods• SwimmeretsSwimmerets
UropodsUropods• Make up tail finMake up tail fin
Exoskeleton Exoskeleton typically typically mineralizedmineralized• CalcifiedCalcified
Nutrition and Digestive SystemNutrition and Digestive System
Many strategies; feed on Many strategies; feed on suspended particles, suspended particles, detritus, carrion, plants detritus, carrion, plants and/or animalsand/or animals
Possess several Possess several mouthpartsmouthparts• Usually have gnathobasesUsually have gnathobases• Coxae of appendages Coxae of appendages
forms a food grooveforms a food groove
Many use a structure Many use a structure called a setal comb to filter called a setal comb to filter feedfeed• Often located on feeding Often located on feeding
appendagesappendages
Most have J – shaped Most have J – shaped gutgut
Often have a grinding Often have a grinding stomach called a stomach called a gastric mill gastric mill
Midgut has digestive Midgut has digestive ceca termed the ceca termed the hepatopancreashepatopancreas
Intestines form and Intestines form and remove wastesremove wastes• Also reclaim waterAlso reclaim water
Anus located at base Anus located at base of telsonof telson
Other Organ SystemsOther Organ Systems Small species don’t require Small species don’t require
complex organ systemscomplex organ systems
HemalHemal• Typical of arthropodsTypical of arthropods• Hemocyanin or hemoglobin Hemocyanin or hemoglobin
dissolved in plasmadissolved in plasma
RespiratoryRespiratory• Gills located in branchial Gills located in branchial
chamberchamber• Inhalant and exhalant Inhalant and exhalant
chamberschambers• Gill bailer (scaphognathite) Gill bailer (scaphognathite)
ventilatesventilates• Many strategies for cleaning Many strategies for cleaning
gills and removing sediment gills and removing sediment from branchial chamberfrom branchial chamber
Excretory systemExcretory system• Paired saccate nephridiaPaired saccate nephridia
Located in segment with 2Located in segment with 2ndnd antennae or 2 antennae or 2ndnd maxillae maxillae Called antennal, maxillary, or green glandsCalled antennal, maxillary, or green glands Nephridiopores open near 2Nephridiopores open near 2ndnd antennae/maxillae antennae/maxillae
Most marine species are osmoconformersMost marine species are osmoconformers
Freshwater species are osmoregulatorsFreshwater species are osmoregulators
Ammonotelic, so nitrogen diffuses across Ammonotelic, so nitrogen diffuses across gillsgills
Nervous system is typical Nervous system is typical of arthropodsof arthropods
• EyesEyes Often compound with as Often compound with as
many as 14,000 ommatidiamany as 14,000 ommatidia Often at the end of a Often at the end of a
movable eyestalk, which movable eyestalk, which greatly increases the field greatly increases the field of viewof view
Some can distinguish colorsSome can distinguish colors
• Many use chromatophores Many use chromatophores to match color of to match color of surroundingssurroundings
• Statocysts and Statocysts and chemosensorschemosensors
Often associated with Often associated with antennaeantennae
Animals frequently clean Animals frequently clean their antennaetheir antennae
ReproductionReproduction All but barnacles are All but barnacles are
gonochoricgonochoric
Usually copulation Usually copulation with internal with internal fertilizationfertilization
Penis or gonopods Penis or gonopods transfer spermtransfer sperm
Appendages such as Appendages such as 22ndnd antennae are antennae are often used to grasp often used to grasp femalefemale
Sometimes males Sometimes males cannot mate with cannot mate with females until after females until after she moltsshe molts
Most brood eggs Most brood eggs attached to attached to appendages or in appendages or in brood chambersbrood chambers
Direct or indirect Direct or indirect (nauplius larva) (nauplius larva) developmentdevelopment
Class AnostracaClass Anostraca
Fairy shrimp and brine shrimp Fairy shrimp and brine shrimp (sea monkeys)(sea monkeys)
Live in ephemeral poolsLive in ephemeral pools• Typically salineTypically saline• Lack fishesLack fishes
15 – 30 mm, but some grow as 15 – 30 mm, but some grow as large as 10 cmlarge as 10 cm
Lack carapaceLack carapace
Sexually dimorphicSexually dimorphic• Males have large 2Males have large 2ndnd antennae antennae
for grasping femalesfor grasping females
Stalked compound eyesStalked compound eyes
Possess setal combs for Possess setal combs for suspension feedingsuspension feeding
Swim upside downSwim upside down
Many tolerate a wide Many tolerate a wide range of salinitiesrange of salinities
Sperm transfer is directSperm transfer is direct• Internal fertilizationInternal fertilization
Class PhyllopodaClass Phyllopoda
800 species800 species
Inhabit freshwater Inhabit freshwater habitats that are habitats that are similar to those of similar to those of anostracansanostracans
Two main typesTwo main types• Large - tadpole Large - tadpole
shrimpsshrimps• Small - water fleasSmall - water fleas
Tadpole ShrimpsTadpole Shrimps TriopsTriops is most famous genus is most famous genus
• Ten species altogetherTen species altogether
Enormous shield-like carapace Enormous shield-like carapace covers most of the animalcovers most of the animal
Most are small, but some reach Most are small, but some reach 10 cm in length10 cm in length
Amazing physiologyAmazing physiology• Dr. Carl Reiber’s lab has Dr. Carl Reiber’s lab has
conducted research using conducted research using Triops Triops as a modelas a model
• Survive in hypoxia and anoxiaSurvive in hypoxia and anoxia Hemoglobin subunit recruitmentHemoglobin subunit recruitment
• Produce two types of eggsProduce two types of eggs Summer eggs- thin shelled and Summer eggs- thin shelled and
hatch rapidlyhatch rapidly Winter eggs - undergo diapauseWinter eggs - undergo diapause
Water FleasWater Fleas Also called cladoceransAlso called cladocerans
• DaphniaDaphnia is most famous genus is most famous genus
Often live in ponds and lakes Often live in ponds and lakes where they make up a large where they make up a large portion of FW zooplankton portion of FW zooplankton communitycommunity
Swim using enlarged 2Swim using enlarged 2ndnd antennae as oarsantennae as oars
Undergo cycles of Undergo cycles of parthenogenesis and parthenogenesis and bisexual reproductionbisexual reproduction
Typically brood eggsTypically brood eggs
Two types of eggs producedTwo types of eggs produced
Undergo cyclomorphosisUndergo cyclomorphosis• Seasonal changes in Seasonal changes in
morphologymorphology• Head shape, spines, neck Head shape, spines, neck
teeth producedteeth produced• Evidence suggests these Evidence suggests these
changes are inducible changes are inducible responses responses
Class MalacostracaClass Malacostraca
Many important Many important orders of crustaceansorders of crustaceans
Crabs, crayfish, and Crabs, crayfish, and shrimpsshrimps
23,000 species23,000 species
Tagmatization is Tagmatization is standardizedstandardized
Order StomatopodaOrder Stomatopoda 300 species of mantis 300 species of mantis
shrimpsshrimps
Predators of fish, crabs, Predators of fish, crabs, shrimps, and molluscsshrimps, and molluscs
Raptorial claws are Raptorial claws are extended and retracted extended and retracted rapidly to capture preyrapidly to capture prey
Best developed Best developed compound eyes of any compound eyes of any crustaceancrustacean• Some even have depth Some even have depth
perceptionperception
5 cm – 36 cm long5 cm – 36 cm long
Can be brightly Can be brightly coloredcolored
Many live in burrowsMany live in burrows
Often pair up with one Often pair up with one mate for lifemate for life
SquillaSquilla is most famous is most famous genusgenus
Order DecapodaOrder Decapoda
10,000 species of 10,000 species of shrimps, shrimps, crayfishes, crayfishes, lobsters, and crabslobsters, and crabs
Important Important ecologically and ecologically and economicallyeconomically
All have 10 legs, All have 10 legs, hence the namehence the name
Shrimp-like DecapodsShrimp-like Decapods
Laterally compressedLaterally compressed
Thin flexible exoskeleton Thin flexible exoskeleton (uncalcified)(uncalcified)
Muscular abdomen that Muscular abdomen that can be used for can be used for escaping (tail flip)escaping (tail flip)
Large pleopods for Large pleopods for swimmingswimming
BenthicBenthic
PenaeusPenaeus is a common is a common genusgenus
Snapping shrimpSnapping shrimp• SynalpheusSynalpheus
• Has one extremely Has one extremely large chelipedlarge cheliped
• One movable finger is One movable finger is cockedcocked
• When released the When released the force generated can force generated can stun prey or crack a stun prey or crack a clam shellclam shell
• Also makes a loud noiseAlso makes a loud noise
Lobster-like DecapodsLobster-like Decapods More dorsoventrally More dorsoventrally
flattenedflattened
Heavier legsHeavier legs
ChelipedsChelipeds
Muscular abdomenMuscular abdomen• Tail flipsTail flips• Small pleopodsSmall pleopods
HomarusHomarus and and ProcambarusProcambarus are famous are famous generagenera
Crab-like DecapodsCrab-like Decapods Most dorsoventrally Most dorsoventrally
compressed of the three compressed of the three groupsgroups
Abdomen is greatly Abdomen is greatly reducedreduced• Hermit crabs have a large Hermit crabs have a large
abdomen that is soft and is abdomen that is soft and is housed in a shellhoused in a shell
• Periodically need to find Periodically need to find larger shellslarger shells
Typically walk sidewaysTypically walk sideways
Some like Some like CallinectesCallinectes can can swimswim
Eggs brooded Eggs brooded between the between the cephalothorax cephalothorax and abdomenand abdomen
Types of crabs:Types of crabs:
• Alaskan kingAlaskan king Probably the Probably the
largest crablargest crab
• Mole crabsMole crabs Lack chelipedsLack chelipeds Burrow in sandBurrow in sand
Japanese spider crabJapanese spider crab• Greatest leg span of any Greatest leg span of any
arthropodarthropod
Decorator crabsDecorator crabs• Have hooked setaeHave hooked setae• Attach things to its Attach things to its
exoskeletonexoskeleton• Aids in protection and Aids in protection and
camouflagecamouflage
Dungeness crabDungeness crab• Cancer magisterCancer magister• Probably the most popular Probably the most popular
food crabfood crab
Freshwater DecapodsFreshwater Decapods Crayfish Crayfish
• The most successful with 400 The most successful with 400 species, worldwidespecies, worldwide
• Many live under stones and Many live under stones and some burrowsome burrow
• ProcambarusProcambarus is an invasive is an invasive species in Western USspecies in Western US
ShrimpsShrimps• Most are tropicalMost are tropical• A few species in the USA few species in the US
CrabsCrabs• Usually must return to the sea Usually must return to the sea
at some point to release larvaeat some point to release larvae• Chinese mitten (or river) crab is Chinese mitten (or river) crab is
an invasive in CAan invasive in CA
Terrestrial CrabsTerrestrial Crabs
Adapted for life on landAdapted for life on land
• Morphological adaptationsMorphological adaptations Gills converted into a Gills converted into a
modified lungmodified lung UricotelicUricotelic
• Behavioral “adaptations”Behavioral “adaptations” Typically live near oceans Typically live near oceans
or in other high humidity or in other high humidity habitatshabitats
Visit water to wet body Visit water to wet body and respiratory surfacesand respiratory surfaces
Typically burrow and are Typically burrow and are nocturnalnocturnal
Some brood embryos on Some brood embryos on land and make mass land and make mass migrations to release migrations to release larvaelarvae
Terrestrial hermit Terrestrial hermit crabs (crabs (CoenobitaCoenobita))
Coconut crabs Coconut crabs ((BirgusBirgus))• Climb trees and Climb trees and
open coconuts, open coconuts, which they eatwhich they eat
• Drink sea waterDrink sea water• Can reach one Can reach one
meter in lengthmeter in length• Some can lift 28 kgSome can lift 28 kg
Christmas Island Christmas Island red crabsred crabs• Make mass Make mass
migrations from migrations from forests to the sea forests to the sea every year to mateevery year to mate
Fiddler crabs are Fiddler crabs are considered semi-considered semi-terrestrialterrestrial
UcaUca lives on sand or mud lives on sand or mud beaches or in mangrove beaches or in mangrove swampsswamps
Emerge from burrows Emerge from burrows when the tide is outwhen the tide is out• ForagingForaging• MatingMating• FightingFighting
Dependent on tide to Dependent on tide to bring new food and bring new food and remove wastesremove wastes
The Decapod Hemal SystemThe Decapod Hemal System Heart is not tubularHeart is not tubular
• Rectangular with three pairs of ostiaRectangular with three pairs of ostia
Well developed vasculatureWell developed vasculature• Seven major arteries leaving heartSeven major arteries leaving heart
McGaw and Reiber have studied many McGaw and Reiber have studied many parameters of decapod circulationparameters of decapod circulation
Circulation takes around 40 sec in large speciesCirculation takes around 40 sec in large species
Hemocyanin transports around 90% of oxygenHemocyanin transports around 90% of oxygen
Neurosecretory Organs of DecapodsNeurosecretory Organs of Decapods
Eyestalks are the most important neurosecretory organsEyestalks are the most important neurosecretory organs
Hormones synthesized in neuron cell bodies of eyestalk Hormones synthesized in neuron cell bodies of eyestalk control:control:• MoltingMolting• ChromatophoresChromatophores• ReproductionReproduction
Sinus gland in eyestalk stores and releases hormones into Sinus gland in eyestalk stores and releases hormones into bloodblood
There are a few endocrine organs outside of nervous There are a few endocrine organs outside of nervous system, but these are under nervous controlsystem, but these are under nervous control• Y-organY-organ
Secretes ecdysoneSecretes ecdysone Located in anterior cephalothoraxLocated in anterior cephalothorax
ChromatophoresChromatophores Located in connective tissue, Located in connective tissue,
deep to the epidermisdeep to the epidermis
Color change is apparent in Color change is apparent in areas where the cuticle is thin areas where the cuticle is thin or transparentor transparent
Used for:Used for:• Thermoregulation – blanching Thermoregulation – blanching
in fiddler crabsin fiddler crabs• Concealment – many shrimps Concealment – many shrimps
change color to match change color to match surroundingssurroundings
Astaxanthin is a carotenoid Astaxanthin is a carotenoid pigment found in decapodspigment found in decapods• Is blue in live animals, because Is blue in live animals, because
it is bound with a proteinit is bound with a protein• Boiling denatures the protein Boiling denatures the protein
and the animal turns redand the animal turns red
Decapod ReproductionDecapod Reproduction
CopulationCopulation• Hermit crabs have to Hermit crabs have to
partially exit shellpartially exit shell
Sperm transfer is Sperm transfer is indirect indirect • Spermatophore extruded Spermatophore extruded
from penes, onto from penes, onto gonopodsgonopods
• Transferred by gonopodsTransferred by gonopods Most anterior pair of Most anterior pair of
pleopods, that are modifiedpleopods, that are modified
Aquatic species attract each other using pheromonesAquatic species attract each other using pheromones• Tactile cues are also importantTactile cues are also important
Visual and sometimes auditory cues are important to Visual and sometimes auditory cues are important to terrestrial speciesterrestrial species• Combat between male fiddler crabs Combat between male fiddler crabs
Egg mass is known as a sponge, and is brooded on Egg mass is known as a sponge, and is brooded on pleopodspleopods
AutotomyAutotomy
Limbs occasionally get Limbs occasionally get autotomized (removed)autotomized (removed)• PredatorsPredators• Self amputationSelf amputation
Little bleedingLittle bleeding
Limb bud formsLimb bud forms• New limb regenerates New limb regenerates
insideinside
Limb bud unfolds during Limb bud unfolds during next moltnext molt• Removing a limb bud Removing a limb bud
delays molting until a delays molting until a new bud forms and limb new bud forms and limb is regeneratedis regenerated
Class Malacostraca, Order EuphausiaceaClass Malacostraca, Order Euphausiacea
85 species of krill85 species of krill
Pelagic, shrimp-like animals found Pelagic, shrimp-like animals found throughout oceansthroughout oceans
Small (about 3 cm long), but found Small (about 3 cm long), but found in enormous densitiesin enormous densities• 60,000 / m60,000 / m33
Chief food for many marine animalsChief food for many marine animals• Blue whale may consume four tons Blue whale may consume four tons
per dayper day
Bioluminescence functions in Bioluminescence functions in schooling and courtship behaviorsschooling and courtship behaviors
Can rapidly molt and leave exuvia Can rapidly molt and leave exuvia behind as decoysbehind as decoys
Order AmphipodaOrder Amphipoda 6000 species of scuds6000 species of scuds
• GammarusGammarus is most famous is most famous genusgenus
Small (5 – 15 mm)Small (5 – 15 mm)• Giant Pacific scuds can Giant Pacific scuds can
reach 28 cm and live 5300 reach 28 cm and live 5300 m deepm deep
Some FW species, and Some FW species, and some semi-terrestrial such some semi-terrestrial such as beach hoppersas beach hoppers• Can leap many times body Can leap many times body
lengthlength
Laterally compressedLaterally compressed
Order IsopodaOrder Isopoda
4000 species 4000 species
Mostly marineMostly marine
Pill bugs (wood lice) are Pill bugs (wood lice) are the most successful the most successful terrestrial crustaceansterrestrial crustaceans
Most are 5 -15 mm, but Most are 5 -15 mm, but the deep sea isopod the deep sea isopod ((BathynomusBathynomus) reaches ) reaches 42 cm42 cm
Dorsoventrally compressedDorsoventrally compressed
Nutritional strategiesNutritional strategies• Some bore into woodSome bore into wood• Some are carnivorousSome are carnivorous• Some parasitize fishesSome parasitize fishes
Have enrollment muscles (pill Have enrollment muscles (pill bugs)bugs)
Terrestrial species specialized Terrestrial species specialized structures to collect water and structures to collect water and channel it to gillschannel it to gills
Class CopepodaClass Copepoda
12,000 species 12,000 species
Most marine, but FW varieties Most marine, but FW varieties dominate zooplankton dominate zooplankton communitiescommunities
Some are parasiticSome are parasitic
Free-living varieties are small (1 - Free-living varieties are small (1 - 17 mm), but some parasites reach 17 mm), but some parasites reach 25 cm25 cm
Long first antennaeLong first antennae• Used by males to grasp femalesUsed by males to grasp females• Usually branch 90Usually branch 90° angles, relative ° angles, relative
to longitudinal axisto longitudinal axis
Possess a median nauplius Possess a median nauplius eyeeye
Form oil droplets for Form oil droplets for buoyancy, which can lead buoyancy, which can lead to petroleum depositsto petroleum deposits
Some undergo DMV of Some undergo DMV of around 300 maround 300 m• One researcher figured out One researcher figured out
that this is the greatest that this is the greatest movement of biomass on movement of biomass on the planetthe planet
Famous genera:Famous genera:• CyclopsCyclops• TisbeTisbe
Swarm on small fish and Swarm on small fish and eat at their finseat at their fins
After fish is immobilized, it After fish is immobilized, it is devouredis devoured
Class CirripediaClass Cirripedia BarnaclesBarnacles
Secrete and inhabit a rigid Secrete and inhabit a rigid calcareous shell that is capable calcareous shell that is capable of growthof growth
Sessile animals that encrust on Sessile animals that encrust on rocks, timber, ships, and even rocks, timber, ships, and even whaleswhales
Fouling ability is amazingFouling ability is amazing• May reduce speed and fuel May reduce speed and fuel
efficiency of a ship by 30%efficiency of a ship by 30%
Abundant intertidally, and may Abundant intertidally, and may be found in distinct patters of be found in distinct patters of zonationzonation• Due to interspecific competitionDue to interspecific competition
Larvae settle and Larvae settle and cements to substrate cements to substrate using glands on its using glands on its headhead• Ventral aspect is upVentral aspect is up• Six pairs of cirri on Six pairs of cirri on
thorax are used for thorax are used for filter feedingfilter feeding
HermaphroditicHermaphroditic• Highly extensible Highly extensible
penis deposits sperm penis deposits sperm in a neighboring in a neighboring barnaclebarnacle
Calcareous shell is Calcareous shell is secreted by exoskeletonsecreted by exoskeleton
There are two pairs of There are two pairs of ventral, movable ventral, movable calcareous plates that form calcareous plates that form an operculuman operculum• Scuta – anterior platesScuta – anterior plates• Terga – posterior platesTerga – posterior plates
Muscles control aperture Muscles control aperture diameterdiameter
Ecdysis occurs but Ecdysis occurs but calcareous shell / plates calcareous shell / plates aren’t shedaren’t shed
Shell is added on to with Shell is added on to with new secretionsnew secretions
DiversityDiversity• Acorn barnaclesAcorn barnacles
BalanusBalanus Those on West coast Those on West coast
of South America of South America can be 23 cm high, 8 can be 23 cm high, 8 cm wide, and are cm wide, and are eaten locally eaten locally
• Stalked barnaclesStalked barnacles Have a peduncle and Have a peduncle and
capitulumcapitulum LepasLepas can grow to can grow to
75 cm in height75 cm in height
Some do not produce shellsSome do not produce shells• Bore into rocksBore into rocks
Others parasitize crabsOthers parasitize crabs• Barnacles alter crab’s behavior, physiology, Barnacles alter crab’s behavior, physiology,
and anatomyand anatomy Molting suppressedMolting suppressed Reproduction suppressed, in fact most are sterilizedReproduction suppressed, in fact most are sterilized Male crabs become feminized and develop a larger Male crabs become feminized and develop a larger
female abdomen, into which barnacle places its own female abdomen, into which barnacle places its own brood pouchbrood pouch
• Betters suits the barnacle’s needsBetters suits the barnacle’s needs
Class OstracodaClass Ostracoda
6000 species of seed 6000 species of seed shrimps that resemble shrimps that resemble miniature clamsminiature clams• Have a bivalved carapaceHave a bivalved carapace
0.25 – 25 mm 0.25 – 25 mm ((GigantocyprisGigantocypris))
Some have cephalic silk Some have cephalic silk glands and spinnerets that glands and spinnerets that secrete silk threads used secrete silk threads used for:for:• DraglinesDraglines• Building shelters for molting Building shelters for molting
Carapace is an Carapace is an extension of headextension of head• Is shed with each moltIs shed with each molt
Some have Some have bioluminescencebioluminescence• Bluish lightBluish light
• Flashed for periods of 1 Flashed for periods of 1 to 2 secondsto 2 seconds
• Used to attract matesUsed to attract mates
Class BranchiuraClass Branchiura 200 species of fish lice200 species of fish lice
Ectoparasites of marine and FW Ectoparasites of marine and FW fishes, and tadpolesfishes, and tadpoles
5 – 30 mm in length5 – 30 mm in length
Structural adaptations for Structural adaptations for attaching to hostattaching to host• First antennae have claws First antennae have claws • Mandibles are toothedMandibles are toothed• First maxillae are suckersFirst maxillae are suckers
Produce digestive enzymes to Produce digestive enzymes to erode host tissue, and feed on erode host tissue, and feed on blood and mucusblood and mucus
Infestations in fish farms can Infestations in fish farms can eradicate entire populationseradicate entire populations
top related