Range Extension of the Paleback Darter

Surveys from 1990 through 1992 resulted in a significant range extension of the paleback darter, Etheostoma pallididorsum, which is endemic to the Ouachita Mountains. Prior to 1990, it had only been collected in the upper Caddo River drainage and a tributary to the Ouachita River below Lake Ouachita. The collections that extended this darter\u27s range occurred in tributaries of the Ouachita River above Lake Ouachita

Growth Curves of Four Species of Commercially Valuable Freshwater Mussels (Bivalva: Unionidae)

North American freshwater mussels (Bivalvia: Unionidae) have been exploited commercially for over 100 years and have been regulated using shell size limits and/or harvest seasons. Presently, freshwater mussels are considered a threatened faunal group in North America due to the large numbers of endangered, threatened or special concern species. Therefore, management of this fauna should emphasize their long-term sustainability. The objectives of this study were 1) to construct von Bertalanffy growth curves for selected commercially-most-valuable species, Fusconaia ebena, Megalonaias nervosa, Amblema plicata and Quadrula quadrula, from five rivers and two reservoirs, 2) to compare species-specific von Bertalanffy growth curves from different rivers and reservoirs, and 3) to provide information on size at onset of sexual maturity in F. ebena and A. plicata. Von Bertalanffy growth curves of four commercially valuable Ambleminae species were used in this study to compare drainage-specific growth. Growth curves for all four species investigated were significantly different between pairs of drainages. Approximate size at onset of sexual maturity was determined for Arkansas F. ebena and A. plicata. Von Bertalanffy growth curves, coupled with life history and population dynamics information, could be useful in assessing and determining national/state harvest sizes and/or drainage specific harvest sizes once annual growth line formation is confirmed

Unionoida (Mollusca: Margaritiferidae, Unionidae) in Arkansas, Third Status Review

We analyzed stream inventories, phylogeographic studies, community and population estimates, life history and reproductive biology research, and suitable habitat investigations conducted from 1997-2008, as well as the Arkansas Natural Heritage Commission mussel database, to update the conservation status for all native freshwater unionoid bivalves thought to occur in Arkansas. Prior to this study, Harris et al. (1997) reviewed the distribution and status of 75 freshwater mussels considered native to Arkansas and ranked 22 species as endangered, threatened or special concern. We now recognize 85 mussel taxa in Arkansas; however, some of those have yet to be described or their nomenclature remains in a state of flux. The previous inclusion of Fusconaia subrotunda (I. Lea 1831) and Obovaria subrotunda (Rafinesque 1820) in the Arkansas native mussel fauna was based on misidentifications. Within the Arkansas mussel fauna, 19 species (22%) are now considered Endangered, 5 species (6%) are ranked as Threatened, 20 species (24%) are of Special Concern, and unfortunately, 1 species has probably been extirpated