Freshwater mussel, mussel assemblages, nestedness, habitat association


The influence of tributaries on mussel assemblages of the river mainstem are poorly understood. This paper aims to understand differences in mussel habitat associations between tributaries and the Neches River mainstem and if the mussel assemblages are nested in tributaries. During the months June through October in 2016, 28 tributaries and 22 mainstem sites were surveyed in the Neches River using tactile time search. A total of 3,620 individuals were collected, of which 44.5% were collected from tributaries. However, only eight of the 28 tributaries contained mussels, while every mainstem site sampled had mussels. Entrenchment ratio and sinuosity appear to be the variables most correlated with mussel habitat association, indicating that tributary complexity positively influences mussel populations and abundances. Mussel assemblages in tributaries were found to be significantly nested within the river mainstem sites.