Browsing by Author "Basiita, R.K."

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    Differentiated Gonochorism in Nile Perch Lates Niloticus from Lake Victoria, Uganda
    (Uganda. African Journal of Aquatic Science, 2011) Basiita, R.K.; Aruho, C.; Kahwa, D.; Nyatia, E.; Bugenyi, F.W.; Rutaisire, J.
    Gonadal development and structure were examined in 317 Nile perch, Lates niloticus, of 4 to 157 cm SL taken from Lake Victoria, Uganda, in 2005–2006. Macroscopic and histological investigation showed a differentiated gonochoristic pattern, with no juvenile intersexuality. Oogonial cells (9.8 ± 3.0 μm) developed through six distinct stages: chromatin nucleolar oocyte (16.2 ± 3.3 μm), perinucleolar oocyte (33.8 ± 12.1 μm), late perinucleolar oocyte (74.8 ± 16.5 μm), cortical alveolar oocyte (122.6 ± 38.8 μm), secondary oocyte (260.9 ± 61.2 μm) and tertiary oocyte (475.5 ± 70.7 μm). L. niloticus was found to be an asynchronous spawner. The collection of female brood fish for induced spawning should aim at fish with an oocyte size of 475.5 ± 70.7 μm. Four main developmental stages were identified in the testis: spermatogonia (A and B), primary and secondary spermatocytes, spermatids and spermatozoa. Testicular structure conformed to the lobular and cystic type. Copious amounts of sperm were exuded from ripe males when slight pressure was applied on the belly. Milt could therefore be obtained by stripping.
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    Morphometric Variation among Bagrus Docmak (Ssemutundu) of the Ugandan major Water Bodies
    (Journal of Fisheries and Aquaculture, 2014) Mwanja, M.T.; Aruho, C.; Namulawa, V.; Ddungu, R.; Ondhoro, C.; Basiita, R.K.
    Bagrus docmak, locally known as Ssemutundu, is one of the native catfishes of Uganda occurring in lakes Albert, Edward, Kyoga and Victoria; and rivers Kagera and the Victoria Nile. The species is a high value food fish that has been targeted for domestication, a process that requires definition of the different strains/taxa of the species. We investigated the morphological variations based on 22 morphological characters in an attempt to identify the different strains of B. docmak and define the species’ morphological phylogenetics in Uganda’s major water bodies. Morphometric data taken from 372 samples was analysed using multivariate methods in an attempt to establish the morphological phylogenetics relationships within and among the different geographical populations. A scatter diagram based on the two most significant components and a multidimensional scaling plot (MDS) based on Euclidean similarity measure clustered the B. docmak from Uganda’s major water bodies into two groups. One group exclusively contained the Victoria Nile individuals whereas the second group contained the rest of the samples. These two groups require further studying for they may require different management approaches and may have different potential aquaculture traits. The findings are discussed in such a way as to emphasise revival, domestication, culture and sustainable exploitation of the Ssemutundu fishery in the country.