The Dwarf wedgemussel, Alasmidonta heterodon, is a federally listed endangered species of freshwater mussel that historically ranged from New Brunswick in Canada to locations in North Carolina. The species is considered extripated from Canada and in the last decade has been only found in limited numbers at ten geographically fragmented locations. InNorth Carolina, it still occurs in the Neuse and Tar River basins. Alasmidonta heterodon is a long-term brooder, spawning in late summer, gravid in the fall and releasing its glochidia in late winter and the spring. The recovery plan for A. heterodon includes captive propagation and augmentation of remaining populations. Etheostoma flabellare and other darters have proven useful as fish-hosts for rearing juveniles in captivity. However, comparatively low numbers of juveniles have been successfully reared using theserelatively small fish-hosts. Captive propagation using fish-hosts is labor intensive and expensive. In vitro culture of larvae and their subsequent metamorphosis to juveniles in culture media has proven to be a less expensive viable alternative to captive propagation using host fish.
North Carolina State University investigators have successfully reared 13species using in vitro techniques, raised them to maturity and produced second generation juveniles from captive reared stock. Glochidia derived from these in vitro reared adults have the same host attachment preference of naturally reared adults indicating the viability of employing in vitro culture as a less expensive alternative for captive propagation of imperiled species. Although Alasmidonta raveneliana and other endangered species have been successfully reared using in vitro techniques, similar work has not been conducted with Alasmidonta heterodon. We propose studies to attempt the rearing of A. heterodon in vitro and optimizing the nutritional health of recently transformed juveniles. Adult female brood stock will be obtained from streams in the Neuse River Basin. Glochidia will be harvested from the gravid females. The glochidia will be reared in cell culture media and the survival and growth of metamorphosed juveniles will be measured.
