AGES ESTIMATION OF SPINNER DOLPHINS, STENELLA LONGIROSTRIS (CETACEA, DELPHINIDAE) IN THE NORTHEAST OF BRAZIL
Abstract
Teeth were collected from two specimens of spinner do/phins, Stenella longirostris (Gray, 1828), in the Fernando de Noronha archipe/ago (3º51 'S; 32º25 'W), in arder to carry out age estimates through counting of Growth Layer Groups (GLGs) . The methodologydeveloped by Myrick et a/.(1983) was used changing only the histologica/
stain opting for Harris' hematoxylin following Molina and Oporto (1993). The analysis of the tooth sections has shown that specimen No 1 (female, 55.5kg and 1.87m long) was an adult, with at least 18 GLGs. Specimen No 2 (female, 27kg and 1.49m long) was a juvenile between one and two years old. The No 1 specimen was over the limits of the Eastern and Whitebelly stocks, but is within the limits of the Costa-rican and Hawaian stocks, described by Perrin (1975). The No 2 specimen was also above the growth curve described by Perrin (1975) for the total length of S. longirostris, (f we consider that it was 1.5 years of age. This report represents a contribution to a better understanding of the natural history ofS. longirostris in the Western South Atlantic, which is still poorly known.
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References
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