Browsing by Author "Hamad, Muumin Iddi"

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    Determining an alternative sources of sustainable feeds for mud crabs farming and growth performance of Scylla serrata in Tanzania
    (University of Dar es Salaam, 2012) Hamad, Muumin Iddi
    Trash fish and marine gastropods (Terebralia palustris) are traditionally used as primary feed in mud crab (Scylla serrata F) culture in many parts of coastal Tanzania. However, the supply is unpredictable and, if crab farming increases further it may result in local ecological and socio-economic impacts. Introduction of alternative feeds is therefore important to support future mud crab aquaculture in Tanzania and other countries along the East African coast. The main objective of the present study was to determine availability and suitability of using local feed resources for crab farming. Four local resources namely Terebralia, fish offal, maize bran, unwanted dried anchovies remains and remains of home cooked maize (stiff porridge) were experimentally tested. Their suitability as feed for mud crab was tested in the laboratory. There was no significant difference in weight gain (ANOVA, P=0.419) between feed treatments. Newman-Keuls test for the growth showed weekly increase in mean body weight of 4.57±1.24g (SE, n= 4) for Terebralia, 4.05±1.02g (SE, n=4), for fish offal, 4.04±1.04g (SE, n=4) for mixed feed (maize bran and unwanted dried anchovies remains) and 2.30±0.49g (SE, n=4) for home cooked maize (stiff porridge). The field survey showed that intense collection, either for food or for crab feed, can result in changed Terebralia population structures with negative consequences for food security. The results indicate that local waste materials suitable as feed sources for mud crab farming are available in sufficient quantities for small-scale farming activities throughout the year and collection of Terebralia as feed for mud crab farming could affect the Terebralia population.