This project was initiated to propagate larval Ouachita rock pocketbook (Arkansia wheeleri) for population restoration and augmentation in the Little River of Oklahoma and Arkansas. The project continued a previous project in 2013-15. During three field seasons a single female Arkansia wheeleri was obtained and metamorphosed using golden shiner (Notemigonus crysoleucas) as host fish, and also using the in vitro approach of placing glochidia into a nutritive liquid medium in lieu of the fish host (Barnhart 2015). Glochidia were obtained in January of 2018. In vitro metamorphosis was unsuccessful. Although 242 juveniles were recovered from fish hosts, these failed to thrive and survived no longer than 1 month. Failure was attributed to immaturity of the larvae. Although glochidia were removed from the female near the same date as in previous years, persistent egg membranes were present which are associated with immaturity. The main obstacle to captive propagation of A. wheeleri has been obtaining brooding females. Two females have been obtained in the past 4 field seasons (including the previous project). Other factors include low and inconsistent metamorphosis success on known host fish, and growout of early juveniles. Both of these latter factors may depend on timing of collecting and holding of females to ensure fully mature glochidia. Further efforts with this species may hinge on sequestering a population in the field either by caging or by pit-tagging for relocation of freeranging females. Sequestering would facilitate monitoring, collection of brood, and timely return of females to the field.
Barnhart, M. Christopher. Final Performance Report: Federal Aid Grant No. F15AP00923 (E-75-R-2) Propagation and Augmentation of the Ouachita Rock Pocketbook. Springfield: Southwest Missouri State University, 2018.