Abstract

The Cooper Creek catfish (Neosiluroides cooperensis) is an endangered species, endemic to the Cooper Creek catchment of the Lake Eyre Basin in Central Australia. The species is considered at risk from a range of significant biological and anthropogenic stressors, including the recent, rapid spread of translocated sleepy cod (Oxyeleotris lineolata) throughout its range. Little is known of N. cooperensis biology and ecology due to its cryptic nature and restricted distribution within a remote geographical landscape. This study undertook targeted sampling to collect critical biological information, to better evaluate the species’ response to current and future threats. Despite a low catch rate, some important biological observations were made. Notably, a ripe female was collected (TL: 409 mm, W: 575.5 g) with eggs ranging in size from 2.48 mm to 3.30 mm, and an estimated fecundity of 4370 eggs. Patterns in reproductive biology indicate the species is likely to be an annual batch spawner, possibly cued by early summer storms. Dietary analysis showed a narrow diet [Levins’ standardized niche breadth: 0.33 (BA)] dominated by gastropods and bivalves. Findings from this study provide significant new information regarding the species’ reproductive biology and ecology, in particular life-history similarities and dietary overlap with invasive O. lineolata. Our findings validate some of the perceived threats to N. cooperensis and will enable future work to accurately assess risks to population viability. Ultimately, these findings will be integral to the development of a conservation plan for Cooper Creek catfish.