Intraspecific variation in stream fish with emphasis on trophic ecology

Abstract

Assessing intraspecific variability in community structure and functioning are still scarce for stream-dwelling fish. However, measuring ecological traits for individuals is important since species’ response for environmental conditions occurs at the individual level, especially in streams which suffers constantly physical disturbances. Intraspecific variability can be measured for several ecological traits, such as morphology, diet, life-history, and habitat use that varies between populations or within populations. Here, we present some methods and studies that evaluated intraspecific trophic variability in stream-dwelling fish. Results revealing the role of individual variation in structure of biological populations and/ or communities were selected, and principal issues were discussed. There are a lot of statistical tools that can test individual variation including functional indexes and multivariate analyzes. Results generated from such individual analyzes have high potential to explain the functioning of stream fish populations and communities.