 In some parenting species , young from a previous spawning batch may stay with their parents and help care for the new young . This is known to occur in around 19 species of cichlids in Lake Tanganyika . These helpers take part in cleaning and fanning eggs and larvae , cleaning the breeding hole and protecting the territory . They have reduced growth rate but gain protection from predators . Brood parasitism also exists among teleosts ; minnows may spawn in sunfish nests as well as nests of other minnow species . The cuckoo catfish is known for laying eggs on the substrate as mouthbrooding <unk> collect theirs and the young catfish will eat the cichlid larvae . Filial cannibalism occurs in some teleost families and may have evolved to combat starvation . 
