Ecology of invertebrate predators in a Coastal Plain stream

Autor: Lane C. Smith, Leonard A. Smock
Rok vydání: 1992
Předmět:
Zdroj: Freshwater Biology. 28:319-329
ISSN: 1365-2427
0046-5070
DOI: 10.1111/j.1365-2427.1992.tb00590.x
Popis: SUMMARY 1. The spatial and temporal abundance patterns, production and feeding habits of invertebrate predators were determined in a sand-bottomed, headwater stream in Virginia, U.S.A. 2. Annual mean density and biomass of predators in debris dams were 3897 individuals m−2 and 2.5 g dry mass m−2, respectively, but only 711 individuals m−2 and 0.2 gm−2 on the sediment. Predator production was 8.36 gm−2yr−1 in debris dams compared to 1.52 gm−2yr−1 on the sediment. Annual predator production, weighted by habitat availability, was 1.73gm−2yr−1. 3. The predominant taxa in terms of production were the chironomids Thienemannimyia spp, complex, Ablabesmyia parajanta, Zavrelimyia sp., and the odonate Cordulegaster maculata. Chironomidae and Odonata together comprised 77% of the production of the predator guild. 4. Based on gut content analysis and calculations of the trophic basis of production, estimated predator production was supported mostly by Chironomidae (38%), detritus (20%), unidentifiable insects (14%), and Ephemeroptera (11%). Total food ingestion by predators was 9.8 gm−2yr−1, 63% of which was detritus and 37% of which was animal material on an areal basis. The predator guild consumed an estimated 94% of primary invertebrate consumer production on the channel surface of the stream.
Databáze: OpenAIRE
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