Environmental Correlates of Distribution and Abundance for Lythrurus snelsoni: A Range-Wide Analysis of an Endemic Fish Species

Lythrurus snelsoni, the Ouachita Mountain shiner, is an endemic fish species in the Little River system of Ouachita Mountains of southeastern Oklahoma and southwestern Arkansas. We collected distribution, abundance, and associated habitat data for 74 sites throughout the range of this species. Univariate analyses identified four environmental variables that significantly predicted the presence of L. snelsoni, while a multivariate analysis identified a suite of six environmental variables that together correctly classified the presence or absence of L. snelsoni at 60 of 74 collection sites. Another group of six environmental variables explained 65% of the variation in L. snelsoni abundance across its range. In general, L. snelsoni presence was strongly associated with high elevation streams with boulder substrates. Abundances tended to be highest in small streams with good riffle and pool development. L. snelsoni was common across its geographic range. However, the species' restricted distribution renders it vulnerable to large-scale watershed disturbances such as clearcutting and reservoir construction.