부산대학교 도서관

In this paper, our goal was to test fish–environment relationships at headwater streams using three different taxonomic levels (species, family, and order) considering two hypotheses: i) fish–environment relationships are expected to occur at higher taxonomic levels; ii) fish–environment relationships are expected to differ among distinct families and orders. We sampled 37 headwater streams using the electrofishing method and we collected information for nine environmental variables: channel depth and width, luminosity, pH, dissolved oxygen, water temperature, conductivity, turbidity, and velocity. For each level, we constructed one occurrence matrix and one environmental matrix to test their co-structure through a Co-inertia analysis followed by a Monte-Carlo test. We found 75 species belonging to six fish orders and 23 families. Our findings revealed significant fish–environment relationships at headwater streams for both species and family levels but not for order level. We found that the set of variables affecting species occurrence is also responsible to influence the family's distribution. These results may indicate that, in the lack of information for species, the family level be used in substitution to seek for fish–environment relationships. However, before that, more studies are needed in order to show whether these patterns are consistent for other regions of the world. [ABSTRACT FROM AUTHOR]