What a totally cool concept — fish risk management! You just have to give this Science Daily article a read. It’s a fascinating account of risk management among cichilids.
Adoption is fairly widespread in the animal kingdom, which seems unlikely and out of line with Darwin’s theory of evolution, but according to Franziska Schaedelin and colleagues at the University of Veterinary Medicine, Vienna, the practice is really a risk management strategy.
According to Science Daily, “Sharing the care of broods among different families thus represents a kind of insurance policy against the predation of a nest. Schaedelin summarizes the findings neatly: ‘in a species that is so highly predated, it must have been important to develop a strategy to ensure that at least some of the young survive. It seems that fish do this by not putting all their eggs (or young) in one basket.'”