Immunological profile of white shellfish Mesodesma mactroides (Mesodesmadidae) from the south coast of Rio Grande do Sul

Author: Juan Jethro Silva Santos (Currículo Lattes)
Supervisor: Dr Luis Alberto Romano

Abstract

The white seafood Mesodesma mactroides has historically been an important fishing resource in the extreme south coast of Brazil, Uruguay and Argentina, however, its current stocks are decimated due to massive, undefined mortality, and overexploitation, which makes it impossible to commercial use. In this context, the objective of the following work was to understand, through a basic study, the state of the immune system of the species in question, at six different points, with different anthropic exposures (Molhes da Barra, Marine Aquaculture Station-EMA, Altair Ship , Sarita Lighthouse, Albardão Lighthouse and Molhes da Barra-Chuí/RS), during the four seasons. The immunological hemato83 parameters selected for such evaluation were: hemocyte characterization and differential count,apoptotic index and histopathology. In the characterization of hemocytes of white seafood, hyaline and granular types were found. The differential hemocyte count did not show significant differences in the organisms collected in the spring and autumn, however in the summer and winter there were significant differences between the different points. The apoptotic index suffered greater variation in the Molhes da Barra, in the summer, suggesting that these organisms are more immunodebilitated. Histopathological analyzes showed the occurrence of the protozoa Trichodina sp. and helminths of the Turbellaria class, but there were no significant differences in the different points and seasons.The results of this work demonstrated that anthropogenic actions associated with environmental variations (temperature and salinity) may be affecting the immune system of M. Mactroides, however, more studies need to be carried out, to contribute to a future management and the malacoculture of this species.

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