Abstract
Survival to hatching was determined after electroshocking embryos of largemouth bass Micropterus salmoides , bluegill Lepomis macrochirus and channel catfish Ictalurus punctatus . Embryos at different developmental stages were exposed for 20 s to homogeneous electric fields (4–16 V cm −1 ) of direct current (DC) or 60 or 120 Hz pulsed direct current (PDC) in water of 100 μS cm −1 ambient conductivity. For all species, DC reduced survival of embryos at developmental stages before, during, or soon after epiboly; but survival did not differ from controls during later developmental stages. Survival of largemouth bass and bluegill was not reduced by 60 or 120 Hz PDC except for bluegill exposed at 12 h post‐fertilization. Channel catfish embryo survival was −1 DC, but survival was not affected. The use of PDC for electroshocking near largemouth bass and bluegill nests could reduce the negative effects on survival of these species; however, PDC can reduce survival of channel catfish embryos.