This study was conducted to produce a high percentage of genetically male tilapia through interspecific hybridization between Nile tilapia, Oreochromis niloticus and Blue tilapia, O. aureus and evaluate sex ratio, productive performance and heterosis of the progeny produced. The results revealed that sex ratios of the progenies of (♀ O. aureus x ♂ O. niloticus) and (♀ O. niloticus x ♂ O. aureus...

The red color pattern in some strains of tilapia has added commercial value in some markets. Although red tilapia may be more marketable, questions have arisen regarding its value as a culture fish. El Gamal (1987) reported that during growout from 130 to 262 g, a red strain of tilapia had significantly lower survival than Oreochromis aureus x Oreochromis aureus and Oreochromis niloticus x Oreo...

Contamination of fish by fungi and their mycotoxins poses major health concerns to human and animals. Therefore, our study was aimed to investigate Aspergillus flavus (A. flavus) infections and the levels of aflatoxins in Nile tilapia, Oreochromis niloticus (O. niloticus), and fish feed. Samples from O. niloticus and fish feed (n=25 for each) were randomly collected from private fish farms at Q...

Nile tilapia (Oreochromis niloticus L.) is the dominant of the introduced tilapiines in many East African lakes and has flourished in the presence of introduced Nile perch (Lates niloticus L.). We explored the hypothesis that O. niloticus exhibits increased omnivory in response to a decline in abundance of haplochromine cichlids. First, we quantified variation in habitat use and diet of O. nilo...

Unaffordability of commercial feeds to semi-intensive Nile tilapia, Oreochromis niloticus farmers has led to reliance on supplemental feeding and fertilization for nutrition of their fish without a scientific basis. This study compared the growth, survival, condition factor and yield performance of O. niloticus fed on mixed ingredients (MI) and rice bran alone (RB) diets reared in fertilized ea...

In this study, we compare the diet, life history characters and abundance of Nile tilapia (Oreochromis niloticus) stocks between two crater lakes in western Uganda (Lake Nyamusingiri and Lake Kyasanduka) that differ in their history of fishing pressure. Both lakes support native fish communities, but also harbour populations of introduced O. niloticus. Lake Nyamusingiri was characterized by a h...

BACKGROUND AND TROPHIC DIVERSITY STUDY Lake Turkana is an understudied desert lake shared by Kenya and Ethiopia. This system is at the precipice of large-scale changes in ecological function due to climate change and economic development along its major inflowing river, the Omo River. To anticipate response by the fish community to these changes, we quantified trophic diversity for seven ecolog...

Fatty acids (FAs) particularly ω3 and ω6 polyunsaturated fatty acids (PUFAs) play important role in human health. This study aimed to investigate the composition and levels of selected ω3 PUFAs in four commercial fish species, Nile perch (Lates niloticus), Nile tilapia (Oreochromis niloticus), Tilapia zillii, and dagaa (Rastrineobola argentea) from Mwanza Gulf in Lake Victoria. The results indi...

This study developed niche models for the native ranges of Oreochromis andersonii, O. mortimeri, and O. mossambicus, and assessed how much of their range is climatically suitable for the establishment of O. niloticus, and then reviewed the conservation implications for indigenous congenerics as a result of overlap with O. niloticus based on documented congeneric interactions. The predicted pote...

The reproductive strategies of Cichlids: Hemichromis fasciatus, Oreochromis niloticus, Sarotherodon galilaeus and Tilapia zillii was studied from June, 2007 to December, 2008. The variability in egg –size (i.e. diameter) were measured using the micrometer eye-piece in a binocular microscope. Fecundity was estimated by direct enumeration and related to the fish species population. The sex ratio ...