Browsing by Author "Chumun, Pramod Kumar"

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    Comparative study of genetic diversity and distribution of symbiodinium harboured by reef building corals common to Tanzania and Mauritius
    (University of Dar es Salaam, 2011) Chumun, Pramod Kumar
    The symbiosis of dinoflagellate micro-algae, zooxanthellae (genus Symbiodinium) with corals is vital for the survival and ecology of reef-building corals. Nevertheless, extremes of climate change induced factors e.g. temperature and irradiance may crumble the association if intolerant zooxanthellac clades are involved. This research aims at establishing the genetic diversity of Symbiodinium in coral species found in selected sites in Mauritius and Zanzibar that experience differing factors such as biogeography, temperature and irradiance levels throughout the year with the view to understand the possible environments such corals are exposed to. Molecular work was performed on five coral species named Galaxea fascicularis (n=51), Acropora muricata (n=49), Pocillopra damicornis (n=30) Porites cylindrical (n=44) and Pocillopora verrucusa (n=31)) in order to classify their different Symbiodinium genetic clades. The 18S- ribosomal DNA of the endosymbiont, which is a highly conserved region, was amplified using zooxanthellae specific primers and the clades were classified by RFLP method. Taq 1 and Hha 1 restriction enzyme were used for the digestion of the PCR product. It was found that zooxanthellae clades A, C and D were present among the studied coral species in both countries but in different proportions. In Zanzibar, clade D was dominant among A. muricata (8 1%) and G. fascicularis (88%) but higher proportion (76% and 68%) of clade C was found in respective Mauritian coral species. P. verrucusa associated more with clade A in Zanzibar (80%) compared to Mauritius (29%) This difference in proportion may be due to varying environmental factors like temperature and light prevailing in the two studied regions or due to stress from climatic changes resulting in coral bleaching. Results obtained can peeve the way for a better understanding of zooxanthellae clade dominance among coral species in the Western Indian Ocean (WIO) region and thus contribute in the long-term management of coral reefs.