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This study assessed the diversity of parasites of milkfish Chanos chanos cultured along
Zanzibar coasts. The study analyzed the prevalence, mean intensity, diversity and
richness of parasites species and to relate the occurrence of this parasites in relation to
physico- chemical parameters of the ponds water and feeding modes of the fish. Three
different localities were selected for this investigation. A total of 110 milkfish were
dissected, the body cavity of each fish removed out ventrally and each organ were cut and
opened separately and kept in physiological saline, hand lenses and dissecting microscope
were used for parasites examination. Out of 110 milkfish examined 59 were infected with
endoparasitic worms, the overall prevalence of infection was 53.64% and mean intensity
of 3.98. The study found that 33 fish were infected with nematodes Camallanus sp. with
prevalence of 30%, 13 fish were infected with Capillaria sp. with prevalence of 11.82%,
23 fish were infected with cestoda Scolex pleuronectis with prevalence of 20.9% while 5
fish were infected with acanthocephalan Cavisoma magnum with prevalence 4.5%. All
parasites were observed in body cavity, 92.34% of these parasites were found in intestines
and 7.66% found in stomach. Results of Shannon and Wiener Index H' of diversity
showed that Donge ponds had high diversity of parasite species compared to Bumbwini
pond 0.89 and 0.75 respectively. While Shakani pond recorded the lowest species
diversity of 0.68. Bumbwini showed high prevalence of 76.67% and parasites mean
intensity of 4.96. Donge had prevalence of 66.67% and mean intensity of 3.6 while
Shakani pond show the lowest prevalence of 32% and mean intensity of 3.1. Also the
observation of this study revealed that parasitic infection was high with increase fish size.
The incidence of parasites did not show relationship with physico - chemical parameters
of the ponds water: temperature, pH, Dissolved oxygen, (DO) and salinity of the water
since p value is greater than significant value, p > 0.05. However parasite communities
varied with different modes of feeding between sites under study. From this finding it is
recommended that farmers should be given adequate technical knowledge on suitable fish culture methods and proper husbandry in order to prevent parasitic infection and disease so as to raise healthy fish and to achieve high production of fish stock |
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