Efforts to Establish a Captive Population of Devils Hole Pupfish

Authors: Olin G* Feuerbacher, Corey W Lee, Darrick S Weissenfluh, Ambre L Chaudoin, Robert M Barlics II, Lee H Simons, Javier Linares-Casenave

Year: 2015 (xlvii)

Abstract

Recovery efforts for Devils Hole pupfish, Cyprinodon diabolis, at the Ash Meadows Fish Conservation Facility (AMFCF) have focused on establishing a captive population from eggs collected from Devils Hole. Eggs were recovered from Devils Hole using nylon spawning mops or carpeted tiles during November 2013 and January 2014. Mops and tiles were deployed 1-7 days on the shallow shelf and subsequently transported to AMFCF where they were inverted and agitated underwater to dislodge eggs and detritus. Recovered material was examined with microscopes to detect eggs. We recovered a total of 60 eggs and one larval pupfish from Devils Hole. Only 65% (n=39) of the eggs contained viable developing embryos. Hatching rate was 55% (n=33) and survival to adulthood was 88% (n=29). Rearing methods included treatment of recovered eggs with formalin, malachite green, and trimethoprim sulfamethoxazole, followed by incubation in acrylic hatching cones. Larvae were given probiotics upon first drinking, and fed a mix of infusoria, newly hatched Artemia, and commercial diets. As fish grew, they were transitioned to frozen and dry feeds. Adult fish (n=29) were moved in May-June 2014 into a 100,000-gallon refuge tank designed to emulate the Devils Hole environment. Attempts to collect eggs from Devils Hole resumed in 2015 and efforts are currently underway to breed these fish in aquaria before they are moved into the refuge tank to augment the existing population.