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6025532 
Journal Article 
Feeding habits of Smicridea (Rhyacophylax) dithyra Flint, 1974 (Trichoptera: Hydropsychidae) larvae in the Los Molles stream (San Luis - Argentina) 
Gil, MA; Tripole, S; Vallania, EA 
2008 
Acta Limnologica Brasiliensia
ISSN: 0102-6712
EISSN: 2179-975X 
20 
1 
1-4 
The aim of this work was twofold: to determine the feeding habits of Smicridea (R.) dithyra larvae using gut content analysis and to establish if there were differences between high and low water periods. The study was carried out in the Los Molles Stream (2 super(nd) order) located in the Potrero River basin at 1,000 m a.s.l. in a semiarid region. Forty-one larvae were captured with Surber sampler of 0.09 m super(2) and 300 mu m mesh. The entomologic material was fixed with formalin at 4% and alcohol at 70%. The gut content was analyzed under microscope with 625x lens. Nine categories of food items and their percentages were determined: leaves fragments, unicellular algae, filamentous algae, amorphous material, inorganic matter, hyphae, invertebrates remains, pollen and fine sediment (<2.5 mu m). When comparing high and low waters, diets did not show significant differences. However, in both periods the highest percentage (70%) was represented by invertebrates and amorphous substances, and the rest included filamentous algae, leaves fragments, inorganic matter and unicellular algae. Smicridea (Rhyacophylax) dithyra was found to be a filterer collector organism that processes fine paniculate organic matter (FPOM), ultrafine paniculate organic matter (UFPOM) and coarse paniculate organic matter (CPOM). The similarities in the seasonal trophic structure might indicate the constant food availability. 
Microbiology Abstracts C: Algology, Mycology & Protozoology; Entomology Abstracts; Ecology Abstracts; ASFA 1: Biological Sciences & Living Resources; Animal Behavior Abstracts; Organic matter; Trophic structure; Trichoptera; alcohols; Hydropsychidae; Freshwater; Formaldehyde; Samplers; Food availability; Inorganic matter; Microscopes; Digestive tract; Streams; Chile, Valparaiso, Los Molles; Rhyacophylax; Argentina; Nutrient deficiency; Sediments; River basins; Feeding; Smicridea; Feeding behaviour; D 04040:Ecosystem and Ecology Studies; K 03450:Ecology; Y 25040:Behavioral Ecology; Z 05340:Ecology and Behavior; Q1 08482:Ecosystems and energetics