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

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.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.German Academic Exchange Centre (DAAD) in Nairobi.mn201

Helminth fauna of Oreochromis leucostictus (Pisces: Cichlidae) from a tropical lake, Lake Naivasha, Kenya

The helminth fauna of Oreochromis leucosticus (Trewavas) from Lake Naivasha is described. The study was carried out on 1,050 gillnetted fish caught over a period of 24 months at different sites within the lake. Oreochromis leucosticus which is a commercially important fish was observed to be a host of four helminth parasites. These were an acanthocephalan polyacanthorhynchus kenyensis (Schmidt and Canaris), a nematode contracaecum sp.. a trematode clinostomum sp. and a dilepidid cestode Amirthalingamia sp. Seasonal variation in prevalence, intensity of infection, organs infected and the variation in infection with the size, sex and body condition of the host are described. There was no seasonal variation in prevalence but intensity of infection was observed to increase with the age of the fish. Although male fish were observed to be more heavily infected, the parasites did not seem to have any significant effect on the body condition of the fish

Contamination of the minnow Rastrineobola argenta, through handling at landing sites and retail markets around Lake Victoria

Background: The quality of fish could be a challenge both locally and internationally as microbial contaminants may result in infections of humans when seafood is handled unhygienically. This is because enteric bacteria such as Escherichia coli, Staphylococcus aureus, Salmonella spp. and Vibrio cholerae are likely to  accumulate in fish where low hygienic standards are maintained. Therefore, studies on fish contamination are critical for the acceptance of fish food locally and in international markets.Objective: To evaluate and compare the microbiological quality of R. argentea at the fish landing sites and local retail markets in Homa Bay County.Design: Purposive, cross-sectional study.Setting: Fish landing sites and retail markets in Homa Bay CountySubject: Studies on fish contamination are critical for the acceptance of fish food locally and in international markets. In this study, Rastrineobola argentea were examined for microbial loads.Results: Samples indicated high levels of coliforms and Escherichia coli in fish. At the landing sites, coliforms ranged from 1.6 x 103 to 4.0 x 103 while E. coli was between 0.8 x101 and 4.8 x 102. In water samples, coliforms ranged between 1.3 x 103 and 1.8x106 / ml whereas E. coli was 1.1x102 to 4.6x101. Personnel hands were found to be contaminated with Salmonella typhimurium and Shigella  dysenteriae. The samples from markets had coliform and E. coli at 5.0x104 to 9.0x105 and 2.0x102 to 4.0x102 respectively.Conclusion: The findings demonstrate that precaution should be taken to improve the hygiene levels along the value chains to ensure that the quality of fish is not compromised