Orconectes williamsi (Williams' Crayfish) is a rare stream-dwelling crayfish that is endemic to the upper White River basin of Arkansas and Missouri. It was described in the 1960s from a type locality in Madison County, AR, and the three localities named in the description comprise the published range of the species in Arkansas. In contrast, 27 locations have been reported in Missouri. This study surveyed a semi-random selection of stream sites in the Arkansas portion of this range in order to characterize the crayfish communities and evaluate the status of O. williamsi in Arkansas. A total of 2372 crayfishes were collected at 68 sites, including 197 Williams' Crayfish from 23 sites. Orconectes meeki meeki (Meek's Crayfish) was the crayfish species most commonly associated with O. williamsi, occurring sympatrically at 87% of sites occupied by O. williamsi. Orconectes williamsi was found in small streams, with coarse substrates and no aquatic vegetation. Orconectes williamsi showed a strong preference for riffle habitats. Due to its limited range and habitat requirements, O. williamsi is moderately imperiled in Arkansas and should be considered rare and vulnerable range-wide.
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics