Análise de anéis diários em otólitos de corvina através da microscopia eletrônica de varredura

The objective of this work was to develop the technique of preparation of otoliths for the evaluation of daily rings by scanning electron microscopy using daily growth rings as tools for the study of corvina (Micropogonias furnieri) growth in different coastal environments of Rio de Janeiro. Otoliths of 30 juvenile fish of this species were analyzed. The otoliths were embedded in resin, cut in a low speed saw and analyzed by a scanning electron microscope. The analyzed fish presented ages of 246 to 523 days for the Guanabara and Sepetiba Bays and 63 to 153 days for the Araruama fish. The growth rates presented significant differences between sites, being higher (rate = 0.083cm.d-1) for the fish of the Araruama Lagoon than the fish of Guanabara Bay (rate = 0.031 cm.d-1) and Sepetiba (rate = 0.032 cm.d-1). Fish in the juvenile and recruitment phases presented higher growth rates, and higher concentration of these individuals in the hypersaline environment of the Araruama Lagoon.