LAUSR

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 longterm 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. The hellbender Cryptobranchus alleganiensis is a large aquatic salamander inhabiting moderate to swift-flowing rivers and streams of the eastern United States, with two recognized subspecies inhabiting the Ozark Highlands of Missouri and Arkansas. One of these, the Eastern hellbender C. a. alleganiensis, has been known to occur in 16 states ranging from central Missouri to southern New York and southwest to northern Alabama and northeastern Mississippi (Petranka 1998). In Missouri, the Eastern hellbender has been known to inhabit the Meramec River, Big River, Gasconade River, Osage Fork of the Gasconade River, Big Piney River, and Niangua River. At this time, Eastern hellbender populations are known to occur in the Gasconade, Big Piney, and Niangua rivers, with some individuals potentially still being present in the Meramec River, Big River, and Osage Fork of the Gasconade River (J. T. Briggler, unpublished data). Native Missouri populations of Ozark hellbenders C. a. bishopi and Eastern hellbenders have declined by more than 70% over the past 40 years due to degraded water *Corresponding author: [email protected] Received May 2, 2018; accepted August 26, 2018 North American Journal of Aquaculture © 2018 American Fisheries Society ISSN: 1522-2055 print / 1548-8454 online DOI: 10.1002/naaq.10065