An automated system for egg collection, hatching, and transfer of larvae in a freshwater finfish hatchery

Abstract

An automated system for egg collection, hatching, and transfer of larvae of several cultured freshwater finfish has been developed. The system consists of a spawning tank, a filter, an incubation tank, hatching nets, and larviculture ponds. Using this system, grass carp (Ctenopharyngodon idellus), bighead carp (Aristichtys nobilis), silver perch (Bidyanus bidyanus), palmetto bass (Morone saxatilis×M. chrysops) and black carp (Mylopharyngodon piceus) were successfully induced to spawn with a single hormone injection (LHRH-a at 15 μg/kg for grass carp and bighead carp; HCG at 200, 400 and 600 IU/kg for silver perch, palmetto bass and black carp, respectively). Using this system, fertilized eggs flowed freely into nets for normal hatching, and the hatched larvae were conveyed automatically into larviculture ponds. The new automated system reduces labor. It achieved relatively high rates of spawning, fertilization and hatching. The filtration and reuse of culture water conserves water. This system offers an improvement to the existing finfish hatchery technology.