Propagation of Eastern Hellbenders Cryptobranchus alleganiensis alleganiensis in a Recirculating Aquaculture System at Shepherd of the Hills State Fish Hatchery

The hellbender Cryptobranchus alleganiensis is an endangered aquatic salamander inhabiting coldwater streams within the Ozark Highlands of Missouri. Over the past few decades, there has been a severe decline in the populations of the two subspecies of hellbender in this region-the Eastern hellbender C. a. alleganiensis and the Ozark hellbender C. a. bishopi-accompanied by little to no recruitment of young age-classes; projections now call for negative long-term population growth for both subspecies. Captive propagation is thus considered essential for the long-term recovery of this species in Missouri, along with addressing the causes for its decline in the wild. Since 2007, Shepherd of the Hills Fish Hatchery has been the primary rearing facility in Missouri for the early life stages of Eastern hellbenders. This facility has focused on hatching fertilized eggs collected from the wild and rearing animals for repatriation into their natal streams. This paper describes the recirculating aquaculture system used to rear Eastern hellbenders, the culture techniques that have been developed, and some of the results.