Egg Disinfection to Improve Conservation Aquaculture of Leatherside Chub

Abstract

AbstractLeatherside chub Lepidomeda copei eggs were obtained as part of separate spawning and life history experiments. This paper summarizes several egg disinfection tests 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, namely, formalin (1,000–2,000 mg/L for 15 min), ultraviolet light (10,200 mW/cm2), or sodium sulfite (1.5% for 5 min). However, petri dish incubation after treatment with copper sulfate (CuSO4) or hydrogen peroxide (H2O2) 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‐d) treatments using H2O2 or CuSO4 did not significantly improve survival to hatch relative to treating only once, but fungal growth was better controlled in the daily H2O2 treatments. The highest percentage of hatching (100%) was observed in petri dishes in which eggs were treated daily with either 1,000 or 2,000 mg/L H2O2 for 2 min. Disinfection of eggs left on the rock substrate was also successful with 60 mg/L CuSO4 when treated on days 1 and 3 postcollection. These data provide information that will help eliminate fungal infection of eggs and remove an obstacle to the conservation aquaculture of this increasingly rare cyprinid.