INTERSPECIFIC BROOD-MIXING IN TANGANYIKAN CICHLIDS

We collected schools of young, guarded by parents, of six common cichl id species to investigate the frequency and origin of interspecific br ood-mixing. The main host species were a piscivore Lepidiolamprologus elongatus and a scale-eater Perissodus microlepis; more than half of t heir schools included heterospecific young, accounting for 20-40% of t he total young. Most of the foreign young belonged to four biparental mouth-brooders whose parents have a habit of carrying their young in t heir mouths. Many of these young were smaller than the largest young b rooded by their own parents. We concluded that adoption of young befor e independence results from farming-out, a behavior by which parents a ctively transfer their young to foster parents.