Ecosystem simulation as an intermediate step to establishing Devils Hole Pupfish in captivity

Authors: Olin Feuerbacher, Jennifer Gumm, Corey Lee, Michael Schwemm, Kevin Wilson, Jeffrey Goldstein, Ambre Chaudoin, Brandon Senger, John Wullschleger, Mitchell Stanton, Javier Linares-Casenave, Alex Jones

Year: 2019

Abstract

The Devils Hole Pupfish, Cyprinodon diabolis, has twice in recent years teetered at the edge of extinction with fewer than 40 animals observed during annual surveys. Establishing a captive population of these fish has proved an elusive goal for decades. Laboratory propagation in aquaria and refuge attempts in large outdoor tanks showed promise, but ultimately failed. Endeavoring to establish a lifeboat population, the Ash Meadows Fish Conservation Facility built upon earlier efforts by utilizing a two-fold approach to population establishment: laboratory rearing of wild-collected eggs through hatch and grow-out until adults were released into a 100,000-gallon refuge tank designed to mimic the challenging habitat and ecosystem of Devils Hole. Adults reared from wild-collected eggs failed to produce viable offspring in aquaria. However, adults stocked into the refuge tank began reproducing, producing successive generations within the refuge tank. Unlike wild-collected eggs, captive-produced eggs subsequently collected from the refuge tank population produced fish which spawned in aquaria and have produced entirely laboratory-reared offspring. Though successful, this approach met significant challenges in the technology required to simulate Devils Hole and to monitor the progression of a complex quasi-ecosystem, and necessitated novel approaches to pathogen and predator control and monitoring of fish and ecosystem health.