5/18/2015  |   15:30 - 15:45   |  101CD

FRESHWATER LEECHES OF NORTH AMERICA Leeches (Hirudinida) are an important component of most freshwater lakes, ponds, and quieter flowing sections of streams and rivers with other species occurring in marine and terrestrial habitats. There are approximately one hundred described species in North America. The majority of North American leeches are predators that feed on a variety of invertebrate prey including chironomids, oligochaetes, amphipods, and molluscs. Other leech species are temporary sanguivorous (blood-feeding) ectoparasites of vertebrates including fish, turtles, amphibians, crocodilians, water birds, and occasionally humans. Leeches can be recognized by having segmented bodies (annelids) with anterior and posterior suckers and feed by a variety of methods, including: using a proboscis, engulfing and two or three jaws. Identification of leeches can often be difficult due to difficulties properly collecting and preserving species and the specialized nature of keys. The goal of this presentation is to provide information on how to collect, preserve and identify freshwater leeches.

Fredric Govedich (Primary Presenter/Author), Southern Utah University, govedich@suu.edu;


Bonnie Bain (Co-Presenter/Co-Author), Dixie State University, bain@dixie.edu;

5/18/2015  |   15:45 - 16:00   |  101CD

THE CONCEPT OF INCIDENCE RARITY, ILLUSTRATED BY THE FRESHWATER GASTROPOD FAUNA OF U.S. ATLANTIC DRAINAGES Our database currently contains 11,471 records of 67 freshwater gastropod species inhabiting Atlantic watersheds from Georgia to the New York line. The incidence distribution appears bimodal, with one peak around 20-30 records and a second peak in the 200-400 range. Adopting the quartile system of Gaston, we suggest that the 0.25(67)=17 species in the left tail of this incidence distribution be defined as “rare,” specially designating the leftmost 5% as rank I-1 and the next 20% as rank I-2. The remaining 50 species we divide equally into ranks of increasing incidence I-3, I-4, and I-5. We define species as “marginal” if evidence suggests that they demonstrate below-median incidence in U.S. Atlantic drainages, but above-median incidence elsewhere. Then seven I-1 and I-2 species are “pseudorare” in our study area, being designated I-1m and I-2m. And an equal number of I-3 species must demonstrate the phenomenon that Gaston terms “non-apparent rarity.” The relationship between the objective system of incidence rarity here proposed previous subjective systems of ranking by “conservation status” is explored.

Robert T. Dillon, Jr. (Primary Presenter/Author), Freshwater Gastropods of North America, dillonr@fwgna.org;

5/18/2015  |   16:00 - 16:15   |  101CD

AN INTRODUCTION TO SAFIT; THE SOUTHWEST ASSOCIATION OF FRESHWATER INVERTEBRATE TAXONOMISTS SAFIT is an independent, nonprofit organization of professional invertebrate biologists whose mission is to promote standardized freshwater invertebrate taxonomy in support of aquatic ecosystem biotic assessments in the southwestern USA. SAFIT is also charged with promoting a better understanding of macroinvertebrate taxonomy and systematics, and fostering scientific research, education, training and professional development of our membership. SAFIT is primarily a support organization for entities conducting aquatic bioassessment.

Christopher Rogers (Primary Presenter/Author), Kansas University/ Kansas Biological Survey, Branchiopod@gmail.com;

5/18/2015  |   16:15 - 16:30   |  101CD

MORE THAN JUST SLIPPERY - THE IMPACT OF BIOFILM ON THE ATTACHMENT OF RUNNING WATER SPECIES EPEORUS ASSIMILS While terrestrial insects usually attach directly to solid substrates like stones or plants, for aquatic insects the situation is more complex due to the growth of biofilm and periphyton on the substrates. Recent investigations indicate that biofilm can strongly influence the ability of benthic animals to attach. This study aimed to prove the impact of biofilm on the attachment of mayfly larvae. We performed attachment experiments in a flow channel, measured attachment forces generated by the claws, and characterised biomechanical properties of the biofilm. The experiments were performed on substrates of different surface roughness each with and without biofilm. On smooth or slightly rough surfaces a layer of biofilm increased the attachment force of claws significantly. The larvae were able to endure higher flow velocities on biofilm-covered smooth substrates in comparison to biofilm-free, smooth substrates. In contrast, on rough substrates the attachment force of claws decreased. Consequently, biofilm is of important ecological relevance for the larvae not only as food source, but also as a factor influencing their attachment ability in natural stream habitats.

Petra Ditsche (Primary Presenter/Author), University of Washington, pditsche@UW.edu;


Jan Michels (Co-Presenter/Co-Author), University of Kiel, jmichels@zoologie.uni-kiel.de;


Alexander Kovalev (Co-Presenter/Co-Author), University of Kiel, akovalev@zoologie.uni-kiel.de;


Jochen Koop (Co-Presenter/Co-Author), German Federal Institute of Hydrology, koop@bafg.de;


Stanislav Gorb (Co-Presenter/Co-Author), University of Kiel, sgorb@zoologie.uni-kiel.de;