Morphological and histopathological alteration in the mussel Brachidontes rodriguezii associated to polluted marine coastal areas.

ARRIGHETTI, F.; TESO, S.V.; PENCHASZADEH, P. E.

Buenos Aires

Congreso; 11th SETAC Latin America Biennial Meeting "The role of science in environmental decision‐making"; 2015

The objective of this study was to determine the presence of morphological and cellular indicators of pollution in the intertidal mussel Brachidontes rodriguezii. For this propose two sites were selected: Villa Gesell (VG) and port of Mar del Plata (MP). The population present in MP is under stress due to the presence of several contaminants in the water, while VG was selected as a clear reference site. Small portions of digestive gland, gonad and gill were fixed, dehydrated and embedded in resin for their histological analysis. In order to quantify the atrophy of the digestive gland five planimetric parameters were analysed: MET, mean epithelial thickness; MLR, mean luminal radius; MDR, mean diverticular radio; MLR/MET and MET/MDR. Significant differences between populations were observed in all the parameters studied, being the ratios MLR/MET and MET/MDR the best indicators of the digestive tubule morphology. Since under normal physiological conditions the digestive cells outnumber basophilic cells, but under different stress situation the relative occurrence of basophilic cells augmented, the volume density of basophilic cells (VVbas) was calculated. VVbas values were much higher in MP population, indicating a cell type replacement situation. Taking into consideration the normal structure of the gill epithelial cells, mussels sampled from MP showed morphological alteration e.g. mucocytes and haemocytes increased. In MP population a more marked incidence of atretic oocytes and atrophic spermatogenic tubules were observed. An analysis of mussels? shell shape from VG and MP areas were performed using geometric morphometric, and significant differences in shell shape among localities were detected.