HR: 11:00h
AN: NB52C-03    [Abstracts]
TI: Distribution and Feeding Preferences of Newfoundland larval Hydropsychidae
AU: * Fietsch, C
EM: w02clf@mun.ca
AF: Memorial University of Newfoundland, Biology Department, St. John's, NL A1B 3X9 Canada
AU: Colbo, M
EM: mcolbo@mun.ca
AF: Memorial University of Newfoundland, Biology Department, St. John's, NL A1B 3X9 Canada
AB: Caddisflies of the family Hydropsychidae (Trichoptera) are widely distributed across North America (145 species), however the large scale distribution of the impoverished Newfoundland fauna (8 species) is unknown. Low species diversity and irregular stream profiles on the island provide a template for community distribution. Sampling a variety of rivers at lake outlets and downstream in forested and barren habitats revealed the influence of landscape on Hydropsychidae distribution and abundance. Forested and barren streams supported the same species of hydropsychids but barren streams generally had much lower densities. Community composition changed on a longitudinal gradient. Extensive measurements of nutrient quantity (phytoplankton, zooplankton, periphyton) did not strongly correlate with community composition or landscape effects. The literature suggests that nutrient quality may have a stronger influence due to premised resource partitioning. One method of investigation is lipid analysis, where nutrient composition is determined via free fatty acid biomarkers. Preliminary results indicate that the fauna are general opportunists, feeding over a range of trophic levels, with outlet community feeding habits being distinctive from downstream. Current trophic categorizations of hydropsychids are questioned.
DE: 1845 Limnology
DE: 9901 NABS Student Award - Basic Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly