university of florida cooperative extension service ... · dwarf mud anemone. small, easy to raise...
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University of Florida Cooperative Extension Service / Institute of Food and Agricultural Sciences Volume 5 Number 2 2001
Continued on page 3.
Calendar ofEvents
Highlighting UF/IFAS Programs in Fisheries and Aquatic Sciences, Aquaculture, and Pond Management
Neighborhood reten-tion ponds are normallynot a thing of beauty—unless someone putssome serious work intogetting rid of the cattails,and making improve-ments. But how? Justask Jack Kennedy ofHillsborough County,who has helped turn hisneighborhood pond intoa work of art.
“Before, you couldn’teven tell it was a retentionpond, it looked so bad,”
says Kennedy. “It wassolid weeds before westarted, with no visiblewater. When we werethrough, it looked sonice, the county com-missioners presentedus with a certificate ofappreciation. They alsogave us a metal parkbench for the pond.”
The pond is perhapsan acre in size, and suf-fered from years of ne-glect. It was a lot of hardand dirty work.
“Three of us workeddiligently at it, althoughone of the guys recentlymoved away,” saidKennedy. “It was hard toget the neighbors to help.
“Hillsborough Countyis good about providingdumpsters on request forthis kind of work. They
Creating A Neighborhood Pond
April 24Managing Ponds for Fishing WorkshopAgriculture Center/Bronson, FLAnthony Drew 352/486-5131
May 12Annual Eco-Gardening ConferenceUSF Campus/ Tampa, FLSydney Brown 813/744-5519 ext 145
May 14-18Aquatic Weed Control Short CourseFt Lauderdale Research & Education CenterVernonVandiver, Jr. 954/577-6316
May 14-25Diseases of Warmwater FishRuskin/St. Augustine, FLAnn Groover 352/392-5930
Nov 27 – Dec 1Marine OrnamentalsConference 2001Walt Disney Resort/Buena Vista, FLBeth Miller Tipton352/392-5930
Student Involvement at UF
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Undergradate and graduate students are an important part of the teaching,research, and extension programs at the University of Florida. Student involve-ment is highlighted in each issue of WaterWorks.
The following UF/IFASfaculty and staff areavailable to answerquestions or providetechnical support foraquaculture, fisheriesand aquatic sciences,and pond manage-ment. Feel free tocontact them.
Agricultural &BiologicalEngineering
County ExtensionFaculty
Frank ChapmanReproductive Biology352/392-9617 ext [email protected]
Chuck CichraPond Management &Fish Biology352/392-9617 ext [email protected]
Ruth Francis-FloydFish Health/Aquaculture352/392-9617 ext [email protected] fas.uf l .edu
Ruth Ellen BowenFish Health352/392-9617 ext 230
Andy LazurFood & Bait Aquaculture850/[email protected]
Debbie Britt PouderFood & Bait Aquaculture850/[email protected]
Craig WatsonResearch Coordinator813/[email protected]
Roy YanongFish Health/Aquaculture813/[email protected]
Ken LangelandAquatic Plants352/[email protected]
Eric CurtisFish Health813/671-5230
John BrennemanPolk/Hillsborough Counties941/[email protected]
Chris BrooksDade County305/248-3311 ext 230
Max GriggsEscambia County850/[email protected]
Bill MahanFranklin County850/[email protected]
Leslie SturmerShellfish AquacultureMulti-County352/[email protected]
Don SweatPasco County813/[email protected]
Ray BucklinAquaculture Engineering352/[email protected]
Chuck AdamsMarine Economics352/392-1826 ext [email protected]
David ZimetFreshwater Economics850/[email protected]
Fisheries and Aquatic Sciences Gainesville
Sam Mitchell Aquaculture Demonstration Farm Blountstown
TropicalAquacultureLaboratoryRuskin
Center for Aquatic& Invasive Plants
Food & ResourceEconomics
Jeff Wilcox has beeninterested in wet slip-pery sea creaturessince his first fishing tripto the Gulf of Mexico atage four. A latebloomer, he got hisBachelor of Science inMarine Biology fromFlorida State Universityunder Dr. Bill Herrnkind in1971.
He earned his Mas-ter of Education fromFlorida A&M University,taking cooperativecourse work in Maricul-ture and Oceanographyunder Winston Menzel atFSU in 1976.
There he stayed for 20years, teaching scienceand aquaculture at theSchool for Applied Indi-vidualized Learning, anationally recognizedalternative high school,and later serving as anAquaculture ExtensionSpecialist at FloridaA&M University. Whiledoing this, he alsoowned and operatedFossil Fish Farm andserved as secretary onthe board of directorsfor the Florida Aquacul-ture Association for tenyears.
Late in life, he decidedthat what he reallywanted to do was fun-damental research inthe marine sciences,which brought him tothe University of Floridato obtain his Ph.D. inFisheries and AquaticSciences.
Jeff works withNematostella vectensis, anestuarine sea anemone,
known as the Starlet orDwarf Mud Anemone.Small, easy to raise andreproductive both sexu-ally and asexuallythroughout the year, theNematostella is servingas Jeff’s model for answer-ing fundamental questionsabout reproduction andearly embryonic celldivision.
Under the tutelage ofDr. Wally Clark, Jeffadded this species to theshort list of Anthozoans(anemones and corals)known to release eggsthat have finished meio-sis before ever meetinga sperm. The egg ofnearly every other sexualanimal must be activatedby spermatozoa before itcan complete reductionof the female chromosomeset to a haploid state.
Throughout the animalkingdom, the norm is forthe male sperm to arrive,activate the egg, andthen wait for the female eggto get ready for the mainevent: fertilization. Jeff hasshown that this is not sowith the Nematostella.The female is ready for
fertilization as soon asthe male arrives.
He has also deter-mined that this littleanemone regulatesearly embryonic divisionthe same way humansdo. When he splits thefirst two cells apart,they become identicaltwins; if he splits thefour cell stage apart,they become identicalquadruplets. Octupletsare harder to get tosurvive, just like humans,but he has succeededa few times even withthis.
Jeff’s most excitingwork has shown thatNematostella embryoscan be manipulated toget the division of thecell without a preced-ing duplication and di-vision of the nucleus.Since it has long beenthought that cell divisionwas merely the resultof nuclear division, ithas been presumedthat they were part ofa single regulatorypathway. While thiswork builds on the pre-ceding work of otherscientists, it serves asproof that these are twoseparate and distinctpathways.
Two pathways ratherthan one means thatnow there should betwice as many oppor-tunities for researchersto discover a means tointervene when cell di-vision goes wrong (theresult of which we callcancer).Continued on page 8.
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left it, we filled it.“They also showed us the ‘good’ and
the ‘bad’ vegetation, and what species toplant. They’ve been wonderful, especiallyJohn McGee and Julie Palaschak at theHillsborough County Adopt-a-Pond pro-gram.” Funding assistance was providedby the Southwest Florida Water Manage-ment District.
Some species of plants were alreadyin the pond when they started. The whitelilies, for instance, were growing but hadto be thinned and were relegated to thepond’s center, where they protect the fishfrom birds. Pickerelweed and swamprushwas also already there.
“It was all low-tech work, lots of shovelwork,” said Kennedy. “We had to removeall the cattails. We used a menzi machineprovided by the county to get the cattails out.Initially, we hauled off eight or 10 pickuptruckloads, but that didn’t make a dent. Sowe called the county and asked about thedumpsters.”
Last year the water got very low. How-ever, the nice thing about retention ponds
is that an inch or so of rain will often raisethe water level at least a foot.
Last summer, the pond dropped downto only two feet deep at the center. Duringlow water, Kennedy’s group, called theCumberland Manor Swamp Rats, workedon the edges of the pond, which could bemowed. Last winter’s freezes killed a lotof the vegetation. They raked and gath-ered the dead stuff. Out deeper, theyremoved the lilies exept in the middle.When they received a merciful two inchesof rain in March, the pond level rose at leasttwo feet. Their work each year is generallydone before it gets too hot in summer.
Early on, they tried putting triploid grasscarp into the pond to eat hydrilla. But blueherons killed the carp, which were actuallytwo feet long, too big for the herons toeat. Today, the pond has bass and blue-gill, snakes, frogs and turtles. It’s a prettydiverse wildlife population for a small pond.
As for birds, they now have mallards,moor hens and grebes that utilize theshoreline vegetation for cover. Daily visitorsinclude various herons, storks, and the
Continued from page 1.
occasional roseate spoonbill.Mosquitofish, which eat mosquitos,
were already there and have proliferated.No one complains about mosquitos.
Today, the water is clear. The shorelineplants, which provide cover for wildlife,also filter nutrients washing in fromstormwater runoff. They’ve had no nuisancealgae blooms.
“It all has to be maintained,” saysKennedy. “We have several garbage bagsof trash washing into the pond after eachstorm. The trash has to be cleaned up.We’re proud of the pond and working onit, like a garden, it’s good therapy. It’s goodlow-tech work, sometimes hot and dirty,and with no computer skills necessary.”
The best way to get started?“You begin with the county, see if they
will provide a grade-all, a boom excava-tor, something to take out the undesirablevegetation with a minimum of back work.Somebody in the neighborhood has to bemotivated, make the phone calls, and bein charge. It helps to have someone thereto organize.”
For more information on pond management checkout the following UF/IFAS publications and web sites:
• UF/IFAS Circular 912Aquascaping: Planting and Maintenance
http://edis. ifas.ufl. e d u / M E N U _ FA
• UF/IFAS Circular 707Weed Control in Aquaculture and Farm Ponds
http://edis. ifas.ufl. e d u / M E N U _ FA
• UF/IFAS’ Center for Aquatic and Invasive PlantsFor a wealth of information and photos of aquatic plants see:
http://plants.ifas.ufl.edu
UF/IFAS Aquacultureand Pond Management Update
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UF Teams Up WithUSDA To AddressShellfish ResearchNeeds
A research grant wasrecently awarded to theUniversity of Florida Ag-ricultural ExperimentStation by the U.S. Dept.of Agriculture, Coopera-tive State Research, Edu-cation, and ExtensionService. These federalfunds were allocated toaddress priority needs ofthe shellfish and food fishaquaculture industries inFlorida and should con-tinue for several years.Congressman Allen Boyd,Jr., a friend of aquaculture,was instrumental in secur-ing this federal commit-ment and partnership.
Also in support ofaquaculture, UF/IFAShas identified programareas that warrant specialattention in the years tocome.They include: waterquality and manage-ment, global competitive-ness, and food technolo-gies. In addition, aquac-ulture advisory commit-tees have identified areasof immediate concern.The following researchprojects addressing shell-fish aquaculture will beinitiated this year:♦Expert Assistance andDistance IdentificationNetwork (EADIN). A sys-tem and protocol for rapiddistance identification ofbiological samples, inparticular phytoplankton,
will be developed. Thiswill link shellfish aquac-ulture industry memberswith experts on the ecologyand biology of their region.♦ Preliminary Investiga-tion of Blood Ark andPonderous Ark Culture -Procedures for hatcheryseed production of twopotential commercial bi-valve species will be de-veloped. Their growthand survival under com-mercial conditions will beevaluated.♦ Genetic Issues in HardClam Aquaculture: Molecu-lar genetic techniques willbe developed and usedto examine the issue ofhard clam stock diversity.
Impact of TemperatureAcclimation on ClamShelf Life and BacterialContent during SummerHarvest. Previously de-veloped dry temperingmethods will be refined toincrease clam survival inrefrigerated storage.
The microbial conse-quences of tempering willbe assessed to ensure asafe and high qualityproduct.
This collaboration pre-sents an opportunity forUF and USDA to make along-term commitment inaddressing pertinent re-search needs of theshellfish culture industry.Industry participation andinvolvement is critical inall phases. Informationgenerated from these re-search projects will bemade available throughthe shellfish aquacultureextension program.Leslie Sturmer352/543-5057
Sam MitchellAquacultureFarmBlountstown
Teachers, JustPoint and Click!
Aquaculture is increas-ingly being incorporatedinto the classroom at allgrade levels—not only asvocational training butalso as an excellent teach-ing tool that integratesmath, science, art, socialscience, language arts,environmental awareness,life skills, and more.
Students practicetheory through hands-onapplications that increaseunderstanding and skilllevels. However, integrat-ing aquaculture into theclassroom can be a daunt-ing task for teachers newto the subject. Fortunately,with the growth of theInternet, great informationis at your fingertips.Here are a few goodwebsites to check out.♦ UF/IFAS aquaculturepublications can help inthe technical aspects ofplanning and operatingan aquaculture facility.They can be downloadedfor free from theweb.(Feel free to makecopies for your students.)
http://edis. ifas.ufl.edu /MENU_ FA
♦ At the AquaNIC websiteyou’ll find discussiongroups, publications, andlinks to more aquaculturesites than you can imagine:http://www.aquanic.org
♦Over 150 aquaculturepublications can be foundat the USDA’s RegionalAquaculture Center site.Click on the Southernregion for publicationsmost applicable to ourregion. Materials are freeand can be copied:http://ag.ansc.purdue/edu/aquanic/publicat/usda_rac/racpubs.htm
♦ The University of Arizonain Tucson has developedmany aquaculture pro-grams and materials forteachers and studentsincluding an Aquaculturein the Classroom website:
http://ag.Arizona.edu/azaqua /extens ion /Classroom/home.htm
♦The table of contentsand ordering informationfor Aquaculture andFisheries Management:Renewable NaturalResources StudentReference (Dept. of Ag.Education/Univ. of Arizona)can be found at the follow-ing site. The book includessections on external fishanatomy, fish pathology,water quality, fisheriesmanagement, aquaculturesystems, hydroponics,production manage-ment, and more:http://ag.arizona.edu/azaqua /extens ion /STUDREFR.HTM
♦The National Council forAgricultural Educationhas many publicationsavailable for aquaculturein the classroom, some ofwhich can be down-loaded for free! Ordering
information for other pub-lications by the Councilsuch as the hefty Aquac-ulture Curriculum Guideand Aquaculture “How To”manuals can also be found:
http:// ffa.agriculture.com/aero /counc i l /index.html
♦Be sure to incorporateinformation specific toFlorida by visiting twoFlorida Dept. of Agricul-ture and Consumer Servicesites. Learn about our re-cently streamlined permit-ting process including BestManagement Practicesand the Aquaculture Cer-tification program at theDivision of Aquaculture
http://www.floridaaquaculture.com
♦You’ll find colorful Floridapromotional and market-ing materials, a productsuppliers directory, terrificrecipes (get the culinaryarts class involved!) andspecies brochures withnutritional, information,buying and preparationtips at the Bureau of Sea-food and AquacultureMarketing site:http : / /www.f l –aquaculture.com
♦ Find out the who, what,and where of Florida’saquaculture products bychecking out the latestreview of the industryconducted by the FloridaAgricultural StatisticsService:http:// www.nass.usda.gov / f l / r toc0a .htmDebbie Britt-Pouder850/674-3184
ShellfishAquacultureCedar Key
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UF/IFASExtensionMiami
Miami FishingClinic
Last winter, FloridaSea Grant ExtensionAgent Marella Cranehelped organize a YouthFishing Foundation Clinicon Virginia Key in Miami.
An estimated 72 youthfrom the Catholic Charity/Boys Town and various 4-Hclubs from Broward andMiami-Dade counties hadthe opportunity to fish ina pond full of red drum.Also present were fiverepresentatives from theDistrict 11 juvenile justicesystem, to observe andinteract with the children.
Youngsters, aged 15and younger, gained ex-perience on how to tie aknot, bait a hook, and casta line—in addition tocatch and release fishing.Marella Crane and CliffKunde, Executive Direc-tor of the Atlantic Game-fish Foundation, gave abrief talk about grouperand snapper.
The event was a greatsuccess. For some chil-dren, it was their firstfishing experience. Eachchild went home with afree fishing rod and reel,plus a handful of educa-tional coloring books andstickers. All participantswent on a guided tour ofthe University of Miami’sResearch Aplysia Facility/Hatchery.
Participants were ableto observe sea slugs,long-spine sea urchins,
Departmentof Fisheriesand AquaticSciencesGainesville
Fishing For SuccessFor the past few months,
Fishing For Success (FFS)has been hosting FamilyFishing days for various
Trophies and prizeswere awarded for variouscategories, and everyonewho participated in thecasting contest won a smallpack of fishing tackle.
On March 7, FFS hostedIFAS employees andtheir families for morefishing. Nearly 200 peopleattended that event, andafter a bit of a slow startin the morning, the fishingwas fast, furious, and fun.Judging from the smilesof the participants, bothof these events were en-joyable and memorableevents. One parent ex-claimed, “this is the bestfamily day we’ve ever had.”
FFS plans to host onelarge event a monththroughout the year, target-ing a different group eachtime, so stay tuned formore fishing opportunities.Tom Glancy352/392-9617 x236
flounder, red drum, andnurse sharks. In addi-tion, a special ceremonytook place recognizingEllen Prager, assistantdean and Tom Capo,senior research associ-ate from the University ofMiami, for their supportand contributions to theYouth Fishing Foundation.Sam Porco305/285-8676
groups from the Gaines-ville community. On Feb.10, FFS held the ThirdAnnual Law Enforce-ment Family FishingDay, open to all area lawenforcement personneland their families.
More than 100 people,representing five differentlaw enforcement agen-cies attended the event.Participants fished fromstocked “catching” pondsof the UF/IFAS Depart-ment of Fisheries andAquatic Sciences (FAS),and stayed quite busycatching sunshine bass,bluegill, channel catfishand largemouth bass.
On hand to assistwere volunteers from theAlachua County SheriffsOffice, FAS graduatestudents/staff, and mem-bers of the UF MarineBiology Club (who set upa marine petting pond).
Some thirty UF/IFAS graduate students from the Department of Fisheries and Aquatic Sciences gave their oralpresentations at the Fourth Annual Graduate Symposium Program on April 16-17. Topics ranged from the shallowwater octopii of Fiji to the viability of highway barrow pits for rearing largemouth bass. Pictured here are FASgraduate students, faculty, staff and visitors that came to hear the talks.
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This is the second of a two part seriescovering how to differentiate native andexotic catfish and providing informa-tion on exotic catfish in Florida.
Armored Catfish/PlatedCatfish (Family Callichthyidae)
A single species of the platedcatfish family is currently estab-lished in Florida. The Brown HoploHoplosternum littorale is found inthe upper Kissimmee and St. Johnsrivers and in coastal areas borderingthe Indian River Lagoon in centralFlorida. Its appearance was firstnoted in ditches near the IndianRiver Lagoon in 1995 and its rangeis spreading. The origin of itsintroduction is unknown.
The Brown Hoplo is native tomuch of tropical South Americaeast of the Andes Mountains andthe island of Trinidad. It is a smallspecies only reaching lengths ofabout 9.5 inches. Its body is cov-ered by rows of interlocking armorplates which provide protection. There isa stout spine in each pectoral (side) finand a somewhat smaller spine in the dorsal(top) fin. As the name suggests, the over-all color is brown with numerous darkspots on body and fins. There are two pairsof prominent barbels around the mouth.
Brown Hoplos feed on invertebrates(e.g., insects and worms) and detritus(organic matter) found on the bottom. Itreproduces in an unusual way. The malebuilds a floating nest of bubbles to protectthe eggs. He secretes a sticky mucuswhich makes the bubbles last a long timeand continually adds to and repairs thebubble structure.
Mating with the female occurs under thenest. She expels a small number of eggsat a time which the male fertilizes. He thentakes the eggs into his mouth and blowsthem up into the nest. After laying hereggs, the female leaves and takes no fur-ther part in caring for the offspring. Themale guards the nest until the eggs hatchand the young are free swimming.
Brown Hoplos live in shallow, weedy,mud-bottomed waters in their native range.In Florida, they have invaded similar habi-
Native and Exotic Catfish in Florida Part IIby Jeff Hill
tats such as marshes, ponds, and ditches.Brown Hoplos are also found in canals. Thisspecies has the ability to breath air, allow-ing it to survive in stagnant, low oxygenwaters that would kill many other fishes. Itmay even crawl across the ground for shortdistances to find water if its habitat goes dryand to colonize new areas.
The effect of Brown Hoplos on nativefishes in Florida is unknown. Their rangeis expanding and they may reach highdensities in certain habitats.
Although fairly small, Brown Hoplos areeaten in South America and by a few peoplein Florida. The meat is said to be of highquality. Most Brown Hoplos are collectedwith a cast net rather than hook and line.
Suckermouth ArmoredCatfishes/Plecos (Family Loricariidae)
At least three species of suckermoutharmored catfishes (plecos) are establishedin Florida. (As a group, members of this familyare also commonly called plecos orplecostomus catfish in the tropical ornamentalfish trade.) Two established species are inthe genus Pterygoplichthys, commonlycalled sailfin catfish .
The Vermiculated Sailfin Catfish
P. disjunctivus – is established incoastal streams of Florida’s Gulfcoast north and south of Tampaand in some inland areas in thecentral part of the state.
The Orinoco Sailfin Catfish P.multiradiatus is found in Broward,Dade, and Palm Beach countiesof south Florida. This specieshas been in Florida since about1971. Plecos of this genus havealso been found in the upperKissimmee and St. Johns rivers.
A third established species be-longs to the genus Hypostomusand is found in relatively low num-bers in canals in south Florida. Afew other species in this familyhave also been collected inFlorida, but they are not knownto have established populations.The introduction of these speciesis believed to be the result ofaquarium releases or escape fromornamental fish farms. Sucker-mouth armored catfishes are
native to tropical South America.The nomenclature (i.e., technical aspects
of names) of this family is complex. Addi-tionally, the species are often difficult todistinguish. These factors confuse theissues of which species are present inFlorida and where are they found.
At one time in the literature, the genusname Pterygoplichthys was replaced byLiposarcus, but Liposarcus actually doesnot refer to the species we have in Florida.
There is also some confusion concern-ing records of the genus Hypostomus inFlorida. Some records were probably basedon misidentifications. However, individualsand populations of Hypostomus apparentlyturn up in various places in Florida, persistfor some time, and then seemingly disappear.Nevertheless, Hypostomus occur in southFlorida and have for several years.Plecostomus has also been used as a genusname for members of this family, but it isnot a valid name.
Sailfin plecos are readily distinguishedfrom other fishes in Florida by their hard,rough, armored skin, sucker-like mouthwith a prominent barbel on each side, and
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Brown Hoplo Hoplosternum littorale
Orinoco Sailfin Catfish Pterygoplichthys multiradiatus
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There’s a new little invasive plant pop-ping up in the United States and Floridawhich could become more prevalenthere without some vigilance. This latestmenace, Azolla pinnata, actually re-sembles tiny Christmas trees growing inwater. It’s common name is the featheredmosquito fern.
Occurring from Africa to Australia, thisplant has been cultivated for centuriesin rice fields of Southeast Asia andsouthern China, where it acts as a fer-tilizer while decomposing. Listed as aweed in seven countries, Azolla hasbeen designated a principal or commonweed in India, Thailand and thePhilipines.
In the United States, it has earned arather bad reputation and is now rankedas a Federal Obnoxious Weed. Quick-growing, this “water velvet” will easilyblanket the surface of a water body in ashort period of time under the rightconditions.
Growth requirements include slow orstill water, mild temperatures and a lackof insect predators. Preferred temperaturerange is 59 to 86 degrees, but it canreportedly survive from 23 to 92 degrees.Most of Florida fits nicely into this range.
How does it feed? Azolla obtains nitrogeninternally via a symbiotic relationshipwith the blue-green alga harbored in itsleaves. The fern’s growth is quickly en-hanced by the presence of phosphorous.
In the past year, the plant has turnedup in the United States as an incidentalin nursery cultivation at scattered loca-tions, including on spot in Florida. Lastspring it was found by a Florida Depart-ment of Environmental Protection(FDEP) regional biologist in a few bird-baths at a nursery in the Stuart area.Once identity was confirmed, the plantwas destroyed by the nursery, in coop-eration with federal and state obnoxiousweed staff. Other small colonies havebeen discovered and destroyed in NorthCarolina, Indiana and Tennessee.
Our native mosquito fern, Azollacaroliniana, looks much like this newinvader. However, the exotic fern’sshape is usually deltoid, or triangular.
The shape derives from the plant’s pin-
The Invaders: Azolla pinnata
nate-type branching system, a distinctivefeature among the six or seven Azolla spe-cies known world-wide. Our native specieshas two nearly equal branches arising fromeach growth point. This pattern of branchingmakes the overall shape of a mature plantirregular, instead of geometric.
One can also look at the plant’s rootsas they float in a bit of clear water. ForAzolla pinnata, note that each root hasmany extremely fine lateral branches,making the roots appear feathery. Thenative species has lateral root branches,but they are sparse and harder to see.Azolla pinnata is often described as muchlarger in size when compared to Carolinamosquito fern. However, this charactercan vary a lot depending on the local grow-ing environment.
The color of mature plants can be a clueas well, but don’t count on this aspect tobe a clinching feature. Generally, Azollapinnata is a lighter green than Azollacaroliniana. Both can be affected in colorby local growing conditions. In addition,each may turn reddish-brown when ambienttemperatures are too high or too low, lightis too bright, and/or nutrients too low.
Keep a wary eye out for this little tree-shaped “ornament” invader. It may lurk inwater gardens, aquatic plant nurseries,ponds, canals, and any other pool of wa-ter, large or small. To confirm the identity of asuspicious–looking mosquito fern,contact your local FDEP regionalbiologist or the FDEP Tallahasseeoffice at 850/487-2600.
With thanks to Kathy Craddock-Burks,FDEP.
large, sail-like dorsal fin. These are rela-tively large fish, growing to about 27inches in length. The basic color patternis numerous brown or dark gray spots ona lighter background. There is a singlelarge spine in the dorsal fin, each pectoralfin, and the anal (bottom) fin. The pectoralspines may be covered with numeroussmaller spines that are larger in the malesand are most prominent during breeding.The head is large and wide and the eyesare very small.
These species are difficult to tell apartexcept by a specialist. Hypostomus is simi-lar to Pterygoplichthys, but differs in hav-ing only 7 dorsal fin rays as opposed to10 or more in the sailfin catfish.
Plecos feed along the bottom or sub-mersed objects using their sucker-likemouth to hold onto the substrate. Theirdiet includes algae, detritus, and smallinvertebrates. They dig holes for shelterin canal banks or under rocks or logs. Themale uses a hole to serve as a nest forthe eggs and fry. The female deposits hereggs inside the hole (sometimes on thetop of the cave) and the male guards the nest.
In South America, plecos live in a varietyof habitats including rivers and marshes.In Florida, they live in canals, rivers, lakes,and ponds. Although they may reach highdensities, the effects of plecos on nativespecies in Florida are little known. Theymay damage canal or levee banks byburrowing, resulting in increased siltation.
Although eaten in their native range,plecos are not generally valued as foodfish in Florida. A few people, however, doeat them and their meat is said to be ofhigh quality.
WaterWorks is published by the UF/IFAS Department of Fisheries andAquatic Sciences. Subscriptions toWaterWorks are free, available uponrequest. See subscription form onpage 8. Questions, comments or edi-torial submissions may be submittedby contacting:
Editor Joe Richard 352/392-9617 ext 290
Faculty Advisor Chuck Cichra352/392-9617 ext 249
Bill
Hal
ler
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The Institute of Food andAgricultural Sciences is an EqualEmployment Opportunity -Affirmative Action Employerauthorized to provide research,educational information and otherservices only to individuals andinstitutions that function withoutregard to race, color, sex, age,handicap or national origin.Inclusion of material in thisnewsletter does not constituteendorsement, nor does exclusionrepresent censure of any item,organization, individual, orinstitution by the University ofFlorida/Institute of Food andAgricultural Sciences.
This diminutive relative of the coralshas a great future as a research model.It can serve as a biomedical model forearly human development, since itdivides the same way we do (i.e., inde-terminate cleavage). It forms muscles,nerves, and digestive tissue from asingle cell, just as we do, and with similargenes to those humans use (e.g. Hoxgenes).
The anemone can also serve as a bio-assay organism for estuaries, wherethere are only a few other non-migra-tory species available for this task. Theycan be raised as clones under controlledconditions, sampled for baseline chemi-cal data, put in the field, and resampledlater, to identify pollutants which mightbe missed by other monitoring protocols.
Most importantly, this close relativeof the corals may serve as a model toilluminate how corals regulate their re-productive cycles, what chemicals andwhich environmental cues triggerspawning, and how corals regulate theirearly development.
While most people are unaware of theStarlet Anemone, despite its occurrence
from Portsmouth UK to Vancouver BC,nearly everyone has heard of corals,known for their beauty and also home toa wondrous assortment of fishes andinvertebrates.
Jeff hopes that the work he is doingnow, and in the future, will help both coralsand people long after he is gone.
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Editor / WaterWorksUniversity of FloridaDepartment of Fisheries and Aquatic SciencesPO Box 110600Gainesville, FL 32611-0600Phone: 352/392-9617 ext. 290 Fax: 352/846-1088E-mail: fishweb @gnv. i fas .u f l .edu
Student Involvement at UF (continued from page 2)
Bottom photo:Cell division in a sea anemone embryo.Dividing nuclei are at Anaphase and arefluorescently stained for DNA. Cell divisiononly occurs after nuclear division, and waspresumed to be dependent upon nucleardivision for proper results. Note the back-ground glow of the DNA in the mitochondria.
Top Photo:Cell division in a sea anemone embryo withnuclear replication suppressed (i.e., nonuclei in the embryo). Further nucleardivision would fragment chromosome sets.The fluorescent stain shows that this doesnot occur. Cell division proceeds in theabsence of nuclear division, independently,many times. The glow from theDNA of themitochondria is all there is to see.
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