A statolith morphology and morphometry of doryteuthis plei specimens from são paulo, brazil

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Statolith morphology and morphometry of Doryteuthis plei specimens from São Paulo, Brazil

Barcellos, DD¹ & Gasalla, MA¹

1. Fisheries Ecosystems Laboratory, Department of Biological Oceanography, Institute Oceanographic, University of São Paulo, Brazil, [e-mail], [e-mail].

Cephalopod rigid structures such as gladius, statoliths, crystalline lens, cuttlebone and beaks have been used in studies of growth with different degrees of success. In addition, these (prefiro sem essa palavra) are also commonly used for taxonomic identification of cephalopods in their predator’s diets. This study aims to describe and evaluate the statoliths of Doryteuthis plei in order to provide tools for taxonomic studies and (não sei se isso que tá atrapalhando meu entendimento) in trophic interaction studies to identification this squid, sexual differentiation, and to estimate individual squid size from the statoliths dimensions.( A total of 780 statoliths were analyzed to describe the morphology and morphometry of the structure and ontogenetic development changes resulting from the growth. To describe statolith D. plei, we compared with (we made a comparison with – fizemos uma comparação com, we compared with= nós em comparação com) D. sanpaulensis statolith. D. plei statolith morphology showed similar characteristics of(to - se vc quiser falar características similares à) D. sanpaulensis in terms of size and shape. However, D. plei statoliths have a dome and rostrum less rounded than those of the congeneric species, with tapered ends (eu tiraria essa virgule, : espécies congenérias com extremidades cônicas/afiladas ou algo do gênero?). The rostrum has narrow features in the midline, and extends its area as it ends the portion of the wing. The wing occupies a mean of 28.51% by area, while the portions as the dome and rostrum together occupy 71.49%. We observed a tendency of narrowing the end portion of the rostrum and the domes to the growth of D. plei. There