Abstract
Fish assemblages were sampled seasonally at Village Creek, a blackwater tributary of the Neches River in Hardin County, Texas. Forty four fish species were captured at Village Creek from diverse aquatic mesohabitats, (e.g., backwater pools, deep channel pools, sloping sandbanks, sandy riffles, shallow marginal regions). Principal component (PC) analyses (based on faunal composition at sample sites and including all seasons) were run on two data sets of ten and twenty two species with highest site occurrence. The first PC axis identified a strong depth gradient that contrasted pool and backwater habitats vs. riffle and sandbank habitats. The second PC axis identified a dissolved oxygen gradient between backwaters vs. the stream channel, sandbank and riffle habitats. The ten species with highest site occurrence were also canonically correlated with seven physical parameters from each site. The first canonical correlation gradient was primarily a water temperature gradient secondarily influenced by dissolved oxygen levels, while the second gradient was primarily a dissolved oxygen gradient secondarily influenced by depth. Size structures and relative abundances were examined for the dominant fish sub-populations within mesohabitats and for rarer species that occurred in more than one mesohabitat. Seven species displayed year-round spawning or had extended spawning seasons (e.g., Cyprinella venusta, Pimephales vigilax, Notropis sabinae). Associations between fish assemblage structure and mesohabitats were generally distinct, but were strongly affected by discharge fluctuations.
Moriarty, Loren Joan (1995). Spatial and temporal variation in fish assemblage structure at Village Creek. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1995 -THESIS -M667.