PLANT AND ANIMAL SCIENCES
BY FRANCISCO J. AYALA
Department of Ecology and
University of California, Irvine
" Infanticide has evolved in some animals as a behavior that increases the fitness of the killer. Killing of siblings occurs in birds, amphibians, fishes, and a number of invertebrates. Killing or abandonment of offspring occurs in many vertebrates (as well as humans). A special case of this is filial cannibalism. In the cortez damselflsh, Stegastes rectzfraenum, males defend eggs deposited on rock surfaces within their territories. Males eat a large percentage of the egg clutches they receive, preferentially those that are smaller and at early stages of development. Females preferentially deposit eggs with males caring for other early-stage eggs and avoid males with late-stage eggs.
C.W. Petersen, K. Marchetti, “Filial cannibalism in the cortez damselflsh stegastes rectifraenun,”Evolution, 43, 158-68, Jan- uary 1989.
" The deep-sea bottom...