Leatherside Chub Lepidomeda copei: New Data on Life History and Conservation Aquaculture Techniques

Leatherside chub (Lepidomeda copei) eggs were obtained as part of separate spawning and life history experiments.  This paper summarizes several egg disinfection tests eggs conducted between 2007 and 2010 to develop protocols for controlling fungus and improving hatching success.  Several disinfection strategies that have worked for other species did not result in improved hatch rates: e.g., formalin (1,000-2,000 mg/L for 15 min), ultraviolet light (10,200 mWs/cm²), or sodium sulfite treatment (1.5% for 5 min).  However, Petri dish incubation after treatment with copper sulfate or hydrogen peroxide provided high hatch rates.  Eggs treated with 40 or 60 mg/L CuSO₄ for 2 min had significantly higher hatch rates than untreated controls.  Daily or repeated (2 days) dose treatments using hydrogen peroxide or copper sulfate did not significantly improve survival to hatch relative to treating only once, but fungal growth was better controlled in the daily hydrogen peroxide treatments.  The highest percentage of hatching (100%) was observed in Petri dishes where eggs were treated daily with either 1,000 or 2,000 mg/L hydrogen peroxide for 2 min.  Egg disinfection while still on the rock substrate was also successful using 40-60 mg/L copper sulfate, treating days 1 and 3 post-collection.   The data in this study provides information that will help eliminate fungal infection of eggs and helps clear an obstacle to conservation aquaculture of this increasingly rare cyprinid.