Competition and Predation
The introduction of Lates niloticus, or the Nile perch, to Lake Kyga disrupted predator-prey relationships in the lake. Bagrus docmac, catfish, was the main predator before 1978 and preyed primarily on invertebrates and haplochromine cichlids. The Nile perch then became the dominant predator, though, and by 1978, catfish and other indigenous species had virtually disappeared from the lake. The perch has become a successful competitor because of its prolific reproductive capacity and its large range of prey. The Nile perch shifts its prey selection as the perch increases in size. Young perch feed on invertebrates like copepods and small insect larvae and then move on to small fish. At a length of about 60cm, the perch become completely piscivorous and feed mainly on Oreochromis niloticus, Nile tilapia. The graph to the left shows inverse relationships over time between the population sizes of L. niloticus (Ln) versus O. niloticus (On) as well as L. niloticus and O. niloticus versus other indigenous species in Lake Kioga.
The introduction of Lates niloticus, or the Nile perch, to Lake Kyga disrupted predator-prey relationships in the lake. Bagrus docmac, catfish, was the main predator before 1978 and preyed primarily on invertebrates and haplochromine cichlids. The Nile perch then became the dominant predator, though, and by 1978, catfish and other indigenous species had virtually disappeared from the lake. The perch has become a successful competitor because of its prolific reproductive capacity and its large range of prey. The Nile perch shifts its prey selection as the perch increases in size. Young perch feed on invertebrates like copepods and small insect larvae and then move on to small fish. At a length of about 60cm, the perch become completely piscivorous and feed mainly on Oreochromis niloticus, Nile tilapia. The graph to the left shows inverse relationships over time between the population sizes of L. niloticus (Ln) versus O. niloticus (On) as well as L. niloticus and O. niloticus versus other indigenous species in Lake Kioga.
Twongo, T. "Recent Trends in the Fisheries of Lake Kioga - Ugunda." Food and Agriculture Organization of the United Nations. Fisheries and Aquaculture Department, n.d. Web. 16 May 2014.