A spawning cage for eliminating predation on larvae of the killifish aphanius dispar

The killifish Aphanius dispar is an excellent candidate for use as a biological control of mosquito larvae. Although we are able to induce reproduction throughout the year, there are two major obstacles for mass production-cnnnibalismyyadultsnneggsndd newly hatched fry and fungal overgrowth from uneaten food onto eggs. To solve these problems we designed a cage to suspend in the breeding tanks. Spawning adults were placed in the cages, and eggs fell to the bottom of the tanks. Fry hatched and developed in the tanks, while adults continued to spawn. A specially designed food dish placed in the cages greatly diminished spillage and the subsequent development of fungus on the bottom of the tanks. The separation of adults from eggs facilitated collection of eggs for further investigation (e.g., diameter, hatching time). The use of spawning cages to eliminate predation of larvae by adults makes the mass production of A. dispar more efficient and increases their appeal as a biological control agent of mosquito larvae.