5/19/2015  |   15:30 - 15:45   |  101A

FISH FAT FACTS: OMEGA-3 FATTY ACIDS IN SPORT FISH FROM THE GREAT LAKES BASIN Partners from the USEPA and the Great Lakes Consortium for Fish Consumption Advisories recently undertook a large-scale, multi-state effort to quantify variations in fatty acid content in wild freshwater fish species that are commonly caught and consumed by anglers and their families. Nearly 900 samples, representing 24 fish species, from the Great Lakes Basin were collected between 2010 and 2013 and analyzed for 37 fatty acid types, including omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Potential contributing factors to variation in species’ EPA+DHA content (i.e. size, diet, season, water body characteristics) were also explored. We found that in both inland and Great Lakes waters, piscivorous species contained significantly higher (P < 0.0001) EPA+DHA content than those that were wholly or partly benthivorous. Furthermore, across all diet types, fatty acid content generally decreased as the trophic state index increased. In-depth intraspecific variation in fatty acid content will be discussed further. These findings provide insight into ecological controls on fatty acids in wild freshwater fish and may ultimately allow for the development of more comprehensive fish consumption advice.

Meghan Williams (Primary Presenter/Author), Wisconsin Department of Natural Resources, meghan.williams@wisconsin.gov;


Candy Schrank (Co-Presenter/Co-Author), Wisconsin Department of Natural Resources, candy.schrank@wisconsin.gov;


Elizabeth Murphy (Co-Presenter/Co-Author), USEPA Great Lakes National Program Office, murphy.elizabeth@epa.gov;


Pat McCann (Co-Presenter/Co-Author), Minnesota Department of Health, patricia.mccann@state.mn.us;


Henry Anderson (Co-Presenter/Co-Author), Wisconsin Department of Health Services, henry.anderson@wisconsin.gov;

5/19/2015  |   15:45 - 16:00   |  101A

HABITAT COMPLEMENTARITY OF INTRODUCED FLATHEAD CATFISH (PYLODICTIS OLIVARIS) AND THEIR POTENTIAL IMPACT ON NATIVE FISHES IN THE UPPER GILA RIVER BASIN, NM. Flathead catfish are ferocious piscivores that have been introduced throughout North America, sometimes into waters where native fishes have no evolutionary history with a top fish predator. This has led to the need for more research on the basic ecology of introduced populations of flathead catfish to understand their impacts on native communities. Flathead catfish in the Gila River, New Mexico were implanted with radio transmitters to assess habitat complementarity at seasonal and daily temporal scales. Results from June 2014 to March 2015 indicate seasonal movement was variable among individuals (0m-42,840m) but approximately two thirds of individuals moved less than 200m from initial tagging location, despite variable stream discharge. Nightly movement to presumed feeding locations was common, but never exceeded 70m. Movement behaviors of this organism have helped parameterize preliminary bioenergetics models to estimate consumptive demands for flathead catfish to range from 1,686 g/yr to 4,600 g/yr, depending on size.

Skyler Hedden (Primary Presenter/Author), Arizona Department of Game and Fish, shedden@azgfd.gov;


Keith Gido (Co-Presenter/Co-Author), Kansas State University, kgido@ksu.edu;

5/19/2015  |   16:00 - 16:15   |  101A

OVERLAP IN THE DIETS OF FOUR SYMPATRIC GAR SPECIES OF WESTERN KENTUCKY During the past decade, increased efforts to reintroduce alligator gar (Atractosteus spatula) to the Lower Mississippi River basin have resulted in the early success of low density populations. To ensure sustainable populations of alligator gar, continued monitoring is critical. The reintroduction of alligator gar to western Kentucky, places the species into a system from which it was absent for more than 50 years and occupied by three other native gar species: longnose gar (Lepisosteus osseus), shortnose gar (L. platostomus), and spotted gar (L. oculatus). The objective is to compare diets of these four species within Clarks River, Kentucky. Prey items were collected from stomachs and identified to lowest taxonomic resolution possible. Fish prey were comprised primarily of shad (Clupeidae), freshwater drum (Sciaenidae), and sunfishes (Centrarchidae); a number of macroinvertebrates were also found in the stomach contents. Longnose gar were found to be the most specialized of the gar species. The interactions of these sympatric gar species and their prey are important for reintroduction success and efforts for alligator gar in western Kentucky.

Bradley Richardson (Primary Presenter/Author), Murray State University, brichardson@murraystate.edu;


Michael Flinn (Co-Presenter/Co-Author), Murray State University, mflinn@murraystate.edu;

5/19/2015  |   16:15 - 16:30   |  101A

POPULATION AND INDIVIDUAL INTRASPECIFIC VARIATION IN TRINIDADIAN GUPPIES This study examines variations in diet and feeding morphology of the guppy Poecilia reticulata, Peters, 1859, at both population and individual levels. The guppies were captured in Trinidad & Tobago - West Indies - in reaches of high (HP) and low (LP) predation pressure. Each individual guppy was analyzed for gut contents, and jaw (maxilla) shape. Our results suggest that at the population level, HP guppies feed mostly on aquatic insects (54%) while LP guppies feed on algae (64%). At the individual level, within a population, HP guppies are generalist consumers (p>0,05), feeding mostly on aquatic insects, while LP guppies are specialists (p=0,001), meaning that each individual within the population feeds on a different food source. The mean maxilla shape was significantly different between populations (F= 2.86; df= 14; p<0,01). LP guppies have broader maxilla than HP guppies. Diet and maxilla shape are correlated within the LP population (F= 16.3; df=19; p<0,01). Our data suggest that guppies can alter intraspecific trait diversity among and within populations.

Piata Marques (Primary Presenter/Author), Universidade do Estado do Rio de Janeiro, piata_bio@yahoo.com.br;


Talita Takahashi (Co-Presenter/Co-Author), Universidade Federal de São Carlos, talitakahashi@hotmail.com;


Misha Warbanski (Co-Presenter/Co-Author), University of Victoria, misha.warbanski@gmail.com;


Dawn Phillip (Co-Presenter/Co-Author), University of West Indies, Dawn.Phillip@sta.uwi.edu;


Rana El-Sabaawi (Co-Presenter/Co-Author), University of Victoria, rana@uvic.ca;


Therese C. Frauendorf (Co-Presenter/Co-Author), University of Victoria, tfrauend@uvic.ca;