Captive Propagation of the Devils Hole Pupfish at the Ash Meadows Fish Conservation Facility

Authors: Olin G. Feuerbacher, Jennifer M. Gumm, Corey W. Lee, Michael R. Schwemm, Mitchell R. Stanton, Kevin P. Wilson, Jeffry A. Goldstein, Ambre L. Chaudoin, Brandon L. Senger, Javier Linares-Casenave, John G. Wullschleger, Jon C. Sjoberg

Year: 2018

Abstract

The endangered Devils Hole Pupfish, Cyprinodon diabolis, whose wild population is limited to a single geothermal pool in the Mojave Desert, has been the subject of conservation and management for more than 50 years. Historically, the establishment of quasi-natural, outdoor refuge populations met only marginal and temporary successes, and ultimately failed due to various logistical and biological reasons. Further, despite decades of attempts, traditional propagation via aquaria has never been fully successful. Here, we report the status of the captive population at the Ash Meadows Fish Conservation Facility (AMFCF), a state-of-the-art aquaculture facility that combines aquaria propagation with a simulated natural refuge habitat. Utilizing eggs collected from Devils Hole, we achieved a greater than 80% larval survival to adulthood. At appropriate size, juveniles and young adults are stocked into a 100,000 gallon refuge tank designed to simulate the challenging conditions of Devils Hole. All life stages, including eggs, larvae, and multiple generations of adults occur in the tank. Although the captive population has produced successive generations, the explosive population growth that was hoped for has not yet been realized, and challenges to successful breeding in aquaria remain. In one example, control of predacious diving beetles in the refuge tank has increased egg recovery significantly. Recovered eggs proved more difficult to rear in laboratory conditions compared to wild-collected eggs, due in part to rapid colonization of eggs and aquaria by microbes, resulting in egg and larval death. New rearing methods were subsequently developed and have been successful in controlling deleterious microbes, resulting in a laboratory population from captive-spawned eggs which will be utilized in captive-breeding trials.