Abstract:
Procamallanus lonis (Family Camallaidae) infecting Siganus sp. at higher prevalences
was found to cause growth retardation. This study, therefore, focused principally on
the histopathology caused by the above parasite on a population of Siganus from the
Batticaloa Lagoon. The inflammatory response of the host provides sufficient clues to
the pathogenicity of this parasite on economically important host; these are tissue
invading parasites are more pathogenic rather than merely being intestine inhabiting
parasites. The infections of Procamallanus lonis in Siganus sp., Glossogobious giuris,
Tachysurus sp. and Ompak bimaculatus were studied to assess their pathological effect.
Infected tissue samples, notably from the intestine, liver and kidney were fixed in 10%
formalin and processed for wax embedding. All tissues were cassetted, labeled and
processed for histological sectioning. Five micrometre thick sections were cut and stained
with haematoxlin and eosin. In the intestine infections elicited an inflammatory response
leading to a light epitheloid encapsulation of the parasite. The encysted parasite causing
pressure changes to the surrounding tissue. Heavy nematode infections were accompanied by hypertrophy of the tissue and the formation of a hyper plastic tissue reaction. Suchmarked tissue reactions may alter the absorptive nature of the intestine and presumably, the health condition of the host.
