Conservation introductions of the Running River rainbowfish into Deception and Puzzle Creeks, Australia

Summary

The Running River rainbowfish (Melanotaenia sp.), a newly recognized but still taxonomically undescribed species confined to a 13 km stretch of Running River in Queensland, Australia, faced imminent extinction through hybridization after an introduced population of eastern rainbowfish moved downstream into its range. Researchers from the University of Canberra and James Cook University established insurance populations by translocating fish into two nearby tributaries, Deception and Puzzle Creeks, chosen because waterfalls prevent upstream colonization by the invasive rainbowfish and because both sit on land managed by the Australian Wildlife Conservancy. In 2015, researchers took wild fish into captivity, genotyped 84 individuals to remove two identified hybrids, and set up spawning groups to maximize genetic diversity, funding the genetic work through crowdfunding supported by aquarium hobbyist associations worldwide. Around 4,000 offspring were produced and raised at the University of Canberra before grow-out at James Cook University; releases into Deception Creek took place from November 2016 to January 2017, and into Puzzle Creek in May 2017. Snorkel surveys in Deception Creek confirmed survival and reproduction within three weeks, with fish under three weeks old already present, and by May 2017 the population had expanded roughly 2 km both upstream and downstream of the release site; Puzzle Creek monitoring was still pending. Because the species lacked formal conservation listing, the project received no government funding and depended entirely on university and hobbyist support. The project rates itself successful, crediting the species' hardiness, strong multi-university collaboration, favorable release timing, pristine receiving habitat, and rapid crowdfunded financial support.