Oyster condition index in Crassostrea rhizophorae (Guilding, 1828) from a heavy-metal polluted coastal lagoon

Brazilian Journal of Biology

M. F. Rebelo¹  M. C. R. Amaral¹  W. C. Pfeiffer¹ 

[1] ,Universidade Federal do Rio de Janeiro Instituto de Biofísica Carlos Chagas Filho Laboratório Radioisótopos Eduardo Penna-FrancaRio de Janeiro RJ ,Brazil

关键词: condition index;    oysters;    heavy metal;    polychaete;    Sepetiba Bay;    Brazil;    índice de condição;    ostra;    metal pesado;    poliquetas;    baía de Sepetiba;    Brasil;   

DOI  :  10.1590/S1519-69842005000200019

来源: SciELO

【 摘 要 】

The condition index (CI) of oysters represents an ecophysiological approach to estimate meat quality and yield in cultured bivalve mollusks. In the present study, the CI of oysters from a heavy-metal polluted bay was analyzed with respect to Zn and Cd contamination in soft tissues, spawning, and polychaete infestation. The CI was calculated through a new technique based on molds made to measure the volume of oyster-shell internal cavities. The higher CI values (over 9 in the dry season) were probably related availability of suspended particles rich in organic matter in the bay, while the rapid reduction in the CI from one season to the next at some stations suggests the effect of spawning. Polychaete infestation was considered low (18.7%) and produced no clear CI effects. The Cd in the oyster tissue collected during the rainy season was weak, although still significantly correlated with the CI (r = -0.36; p < 0.05). All other comparisons of CI and metal concentrations demonstrated a non-significant correlation. The CI variations observed on the temporal and spatial scale were likely to have been caused by availability of organic matter and spawning, rather than spionid infestation or metal body burdens.

【 授权许可】

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