The effect of brood size and age on partial filial cannibalism in the scissortail sergeant
Abstract:Within the size range found in the field for the scissortail sergeant Abudefduf sexfasciatus, there was no correlation between the number of cannibalized eggs and total brood size. Very small broods were fully cannibalized. In a manipulation experiment, males were provided with broods of one of three standardized sizes: at the two extremes and in the middle of the range of naturally occurring broods. Brood size had no effect on partial filial cannibalism, but parental effort increased with increasing brood size. Field correlates and the manipulation experiment showed that the cost of cannibalism in terms of current reproductive success decreased significantly with increasing brood size. Contrary to expectations, there was no relationship between male size and the incidence of cannibalism. No preference for younger eggs was found either from field correlates or from a manipulative experiment in which males were provided with an equal number of young and old eggs at the beginning of the parental phase.
Document Type: Regular Paper
Affiliations: Large Animal Research Group, Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, U.K. and Institute of Biodiversity & Environmental Conservation, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia
Publication date: July 1, 2003