Egg cannibalism versus egg predation: Their significance in anchovies

Abstract

Daily egg mortality of the Peruvian anchovy Engraulis ringens was 68 per cent in August/September 1981, an extremely high value. With recently developed methods it was possible to determine that 21, 9 per cent of this egg mortality was the result of egg cannibalism by anchovies. Some 76, 4 per cent of 1 500 anchovy stomachs contained anchovy eggs and the mean number of anchovy eggs in such stomachs was 14, 2. of 577 sardines Sardinops sagax caught in the anchovy spawning area, 62, 1 per cent contained anchovy eggs in their stomachs, the mean number of eggs present being 19, 1. When considering only collections in which sardines and anchovies occurred together, 77, 0 per cent of the anchovies and 86, 2 per cent of the sardines had eggs in their stomachs. The mean number of eggs per stomach was 6, 6 in anchovies and 27, 6 in sardines in these collections. The mean number of anchovy eggs per kilogramme wet fish mass was 335 and 757 for anchovy and sardine respectively. Although the contribution of egg predation by sardines to the total anchovy egg mortality could not be estimated quantitatively, it was obvious that it is important. © 1987 Taylor & Francis Group, LLC.