Cannibalism and intraguild predation in clupeoids

Abstract

Provides empirical data of Cape anchovy Engraulis capensis egg mortality caused by cannibalism and sardine Sardinops ocellatus predation. Rates of anchovy egg mortality during 1986-1988 averaged 0.01 h-1, representing a survival rate of 55% over the 60 h incubation period. Some 56% of anchovy stomachs and 88% of sardine stomachs contained anchovy eggs. Of sardines and anchovies caught in co-habited areas during this period, 67% of the anchovy and 87% of the sardine had anchovy eggs in their stomachs. Mean numbers of eggs observed in stomachs per kg of fish mass of the co-occurrent collections were 24 in anchovies and 2117 in sardines. Up to 56% of the total anchovy egg mortality was the result of sardine predation and up to 6% was the result of anchovy cannibalism. -from Author