Food composition and zooplanktonic prey selectivity of Lates niloticus (Linné, 1762) juveniles in fishponds (Ivory Coast; West Africa)

Abstract

Prey selectivity of juveniles of Lates niloticus was studied by looking at stomach contents of 570 fishes collected from a pond. Zooplankton was also sampled. The results were analysed using the Self-Organising Map and the graphical method of Costello (1990) [J. Fish Biol., 36, 261–263] modified by Amundsen et al. (1996) [J. Fish Biol., 48, 607–614]. Preys, comprising 38 taxa, were predominantly zooplankton (rotifers and copepods). The abundance of prey did not regulate food selectivity and prey size represented a limiting factor for the use of food resources. Lates niloticus juveniles were clearly specialised in copepods but occasionally included small proportions of other prey types (rotifers, ostracods, insects and fishes) in their diet. They foraged at this stage according to the Optimal Foraging Theory. Food preference is affected by the accessibility, motility and energy content of food items.

Keywords

• Lates niloticus
• juvenile
• fish diet
• pond
• Ivory Coast