TITLE:
The Community of Parasites Infecting Clarias gariepinus in the Tanzanian Waters: A Case of Lake Victoria
AUTHORS:
Chacha John Mwita
KEYWORDS:
Population Biology, Parasites, Clarias gariepinus, Lake Victoria, Tanzania
JOURNAL NAME:
Open Journal of Ecology,
Vol.4 No.14,
October
27,
2014
ABSTRACT: Quantitative variations in parasites were investigated with respect to
sex and size of Clarias gariepinus,
season and localities sampled. Parasitic infection in male and female fish was
not significantly different; prevalence (Man-Whitney paired sample test, U =
135.5, p = 0.7697), mean intensity (U
= 136, p = 0.7829). Based on
Kruskal-Wallis test analysis, the prevalence and mean intensity of five
parasite species varied significantly among the three localities sampled. Adult
parasites in Clarias gariepinus showed high abundance during the dry season while the larval forms showed high
abundance in the wet season. In most of the parasite species analyzed the
abundance varied significantly with host size. The abundance of Dolops ranarum, Paracamallanus cyatopharynx and Eumasenia bangweulensis for instance, increased with fish size,
while that of Diplostomum mashonense, Tylodelphys species, Astiotrema reniferum, piscicolid leeches
and Monobothrioides woodlandi increased
initially but decreased as fish length reached 31 - 40 cm. Total parasite
burden increased in fish of 20 - 40 cm standard length. Generally, most
parasites were highly overdispersed and the negative binomial model described
their distribution.