The evolution of body muscle composition of the African catfish (Clarias gariepinus) (Burchell 1822)

Changes in body muscle composition of Clarias gariepinus were studied in fish reared from 1.08 g to 383 g mean body weight in a 201-day culture period. Changes in the amount of protein content, dry matter and ash free dry matter in the muscle tissue can be described as a function of body weight. The percentage of protein content was observed to be higher in bigger fish. Fat content was low throughout the fingerling stage. Specific growth rate decreased significantly at 400 g mean body weight (P<0.05) while feed conversion rate increased. The conclusion, based on the culture conditions in this study, is that the optimal weight for harvesting C. gariepinus is 400 g

A survey of ichthyofauna of Lake Kanyaboli and other small waterbodies in Kenya: alternative refugia for endangered fish species

In 1988, the World Conservation Union (WCU) Red Book of Endangered Species listed hundreds of endemic fishes of Lake Victoria under a single heading - &quot;ENDANGERED&quot;. Most of the endemic native food fishes are either endangered or extinct. However, a survey of the fauna of Lake Kanyaboli, revealed that a few remaining samples of these native fishes are actually thriving. These include several unidentified Haplochromis spp., Oreochromis esculentus and Oreochromis variabilis. As a result, a stock rehabilitation and management strategy has been designed to use Lake Kanyaboli and other small waterbodies as conservation 'Refugia' for endangered fish species of the larger Lake Victoria

Bewitching sex workers, blaming wives: HIV/AIDS, stigma, and the gender politics of panic in western Kenya

Since access to HIV testing, counselling, and drug therapy has improved so dramatically, scholars have investigated ways this 'scale-up' has interacted with HIV/AIDS-related stigma in sub-Saharan Africa. Drawing on data collected during ethnographic research in a trading centre in western Kenya, this paper critically analyses two violent and localised case studies of panic over the ill health of particular community residents as a nuanced lens through which to explore the dynamic interplay of gender politics and processes of HIV/AIDS-related stigma in the aftershocks of the AIDS crisis. Gaining theoretical momentum from literatures focusing on stigma, gender, witchcraft, gossip, and accusation, we argue that the cases highlight collective anxieties, as well as local critiques of shifting gender roles and the strain of globalisation and legacies of uneven development on myriad forms of relationships. We further contend that these heightened moments of panic and accusation were deployments of power that ultimately sharpened local gender politics and conflicts on the ground in ways that complicated the social solidarity necessary to tackle social and health inequalities. The paper highlights one community's challenge to eradicate the stigma associated with HIV/AIDS during a period of increased access to HIV services

Widespread colonisation of Tanzanian catchments by introduced Oreochromis tilapia fishes: the legacy from decades of deliberate introduction

From the 1950s onwards, programmes to promote aquaculture and improve capture fisheries in East Africa have relied heavily on the promise held by introduced species. In Tanzania these introductions have been poorly documented. Here we report the findings of surveys of inland water bodies across Tanzania between 2011 and 2017 that clarify distributions of tilapiine cichlids of the genus Oreochromis. We identified Oreochromis from 123 sampling locations, including 14 taxa restricted to their native range and three species that have established populations beyond their native range. Of these three species, the only exotic species found was blue-spotted tilapia (Oreochromis leucostictus), while Nile tilapia (Oreochromis niloticus) and Singida tilapia (Oreochromis esculentus), which are both naturally found within the country of Tanzania, have been translocated beyond their native range. Using our records, we developed models of suitable habitat for the introduced species based on recent (1960–1990) and projected (2050, 2070) East African climate. These models indicated that presence of suitable habitat for these introduced species will persist and potentially expand across the region. The clarification of distributions provided here can help inform the monitoring and management of biodiversity, and inform policy related to the future role of introduced species in fisheries and aquaculture

A survey of ichthyofauna of Lake Kanyaboli and other small waterbodies in Kenya: alternative refugia for endangered fish species

In 1988, the World Conservation Union (WCU) Red Book of Endangered Species listed hundreds of endemic fishes of Lake Victoria under a single heading - &quot;ENDANGERED&quot;. Most of the endemic native food fishes are either endangered or extinct. However, a survey of the fauna of Lake Kanyaboli, revealed that a few remaining samples of these native fishes are actually thriving. These include several unidentified Haplochromis spp., Oreochromis esculentus and Oreochromis variabilis. As a result, a stock rehabilitation and management strategy has been designed to use Lake Kanyaboli and other small waterbodies as conservation 'Refugia' for endangered fish species of the larger Lake Victoria

The evolution of body muscle composition of the African catfish (Clarias gariepinus) (Burchell 1822)

Changes in body muscle composition of Clarias gariepinus were studied in fish reared from 1.08 g to 383 g mean body weight in a 201-day culture period. Changes in the amount of protein content, dry matter and ash free dry matter in the muscle tissue can be described as a function of body weight. The percentage of protein content was observed to be higher in bigger fish. Fat content was low throughout the fingerling stage. Specific growth rate decreased significantly at 400 g mean body weight (P<0.05) while feed conversion rate increased. The conclusion, based on the culture conditions in this study, is that the optimal weight for harvesting C. gariepinus is 400 g

Recent ecological changes in of Lake Sare, western Kenya

Studies on the ecology of Lake Sare (Kenya) were carried out to provide baseline information on the ecological conditions before a major wetland reclamation project was started upstream of the lake. Results indicated that maximum depth had decreased by 0.9 m while Secchi depth readings had decreased by 0.1 m compared to historical values. This implies that the lake was undergoing siltation. pH values had increased from 6.80 to 7.58 reflecting increased primary production. Conductivity had increased from 106 – 137 2 ~kS/cm. NO3- N and PO4-P had significantly increased from 0.8~kg N l-1 and 0.14 ~kg P l-1 to 23.90.8~kg N l-1 and 34.80.8~kg P l-1 respectively while chlorophyll a values reached 34.8 ~kgl-1. The macrophyte environment was dominated by Cyperus papyrus, Eichhornia crassipes, Phragmites australis, Cyperus papyrus, Eichhornia crassipes, Phragmites australis. The invasion of the lake by Eichhornia crassipes is reported here for the first time. The study further observed macrophyte succession where the floating plants Eichhornia crassipes and Pistia stratiotes were gradually giving way to Vossia cuspidata in the Sare lagoon. The phytoplankton community was dominated by Pediastrum sp., Pseudoanabaena, Synedra sp. and Cyclindospermopsis sp. Cyclindospermopsis sp. has the potential to secrete a toxin Cylindropermopsin which can affects the liver and to some extent the kidney. Zooplankton communities encountered were from the Copepoda, Cladocera and Rotifera genera. The fish community was dominated by Lates niloticus and Haplochromine sp which coexist in this ecosystem. Lake Sare is a high priority ecological site for conservation and management of the resources of Lake Victoria basin. It has direct link with Lake Victoria. Fish populations stocked in the Lake Sare are likely to find their way to Lake Victoria. In view of this the lake can be used as a launch site for restocking Lake Victoria with juveniles of endangered fish species.PublishedReclamation; Wetlands; Introduced species; Ecosystem management; Resource conservation; Resource management; Rare species; Inland waters; Water bodies; Water reservoirs; Freshwater lakes; Zooplankton; Aquatic plants; Freshwater weeds; Phytoplankton; Baseline studies; Ecological distributio