CS35 Trophic Dynamics
Date: Wednesday, June 12, 2002
Location: Poster Session - VCC
 
PearreS, Dalhousie University, Halifax, Canada, pearre@is.dal.ca
 
TROPHIC NICHES OF CHAETOGNATHA AND THEIR FRESHWATER ECOLOGICAL EQUIVALENTS, CHAOBORIDAE (DIPTERA).
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This study compares the trophic niches and their variation with predator size of two important planktonic predators. Chaetognaths and chaoborids are both high-ranking invertebrate pelagic predators in their respective (marine and freshwater) environments. Both are relatively large, elongated, transparent, vertically-migrating, ambush-predators which locate and attack their prey by mechanoreception (vibration-sensing). Because of these striking similarities, some authors have suggested that they are ecological equivalents, i.e., occupy the same relative niche. Using popular conventional taxon-based trophic niche-breadth indices, as well as two prey-size based indices, this study establishes a general relationship for each predator group, with predator sizes varying both within and among species. It then examines the similarities and differences in the ways in which the two groups utilize their trophic environments.