Ecological studies of helminth parasites of the largemouth bass, Micropterus salmoides, from Lake Naivasha and the Oloidien Bay, Kenya

Abstract

The parasites of 541 largemouth bass, Micropterus salmoides, were studied over a period of 12 months. The results showed that the bass from Lake Naivasha are paratenic hosts of Contracaecum sp. larva and final hosts for the acanthocephalan Polyacanthorhynchus kenyensis. The nematode occurred in large numbers in fish caught in the more saline Oloidien Bay but only in small numbers in those in the main lake. Bass in the main lake, however, were more heavily infected with acanthocephalans than those in Oloidien Bay. One of the major pathological effects of the acanthocephalan was perforation of the liver by the spiny proboscis. Seasonal variation was not apparent for either of the parasites. The intensity of infection by Contracaecum sp. larva increased with the size of the host and female fish were more heavily infected than males.