Some notes on the Nile perch (Lates niloticus) in the role of predator in fish-farm ponds

Abstract

During the course of work on the growth and breeding of the Nile Perch at Sagana in Kenya a number of observations were made on populations of Tilapia subject to predation by Nile Perch. This work touches upon a central problem in fish culture, viz., the control of rapidly expanding fish populations by predation where monosex culture or culture of non-breeding species is impractical. Tilapia ponds often present this problem which may be approached by considering stockreduction methods. The use of the Nile Perch in this stock-controlling role is further enhanced by virtue of its qualities as a high-priced table fish. The work on the Luwala Sugar Estate Dam near Jinja, and on the experimental dams at Sagana, suggest two distinct courses of events during stock-control experiments, depending on whether the Nile Perch breeds or not. In further experiments the impact of predation by Nile Perch, and also by Black Bass (Micropterus salmoides) over a short period, is detailed for a limited population of Tilapia nigra, and the sequence by which a suitable prey population is established and utilized is discussed