Biologia reprodutiva da Ostra-do-Mangue Crassostrea rhizophorae (Guilding, 1828) (Bivalvia: Ostreidae) em manguezais da comunidade de Capanema, Maragogipe – Ba

Abstract

This study aimed to know the reproductive characteristics of the mangrove oyster Crassostrea rhizophorae in the community of Capanema, Maragogipe, Bahia, Brazil. Sampling was carried out monthly between August 2016 and September 2017. Twenty oysters were collected at each site for biometrics and weight measurement for the calculation of meat yield and histological analysis, where they were fixed in Davidson's solution, impregnated in paraffin and stained with Harris Hematoxylin and Eosin. The water temperature ranged from 21 ° C to 30 ° C, with little variation (p> 0.05) between sites. The salinity varied between 13.75 and 30 ppm. The height of the oysters examined ranged from 26 to 97 mm with a mean of 51.03 mm (SD ± 11.5). 29.6% of oysters had empty gonads and 24.6% had full gonads. Oysters at filling were predominant, recording 45.8%. The different stages of gonadal maturation did not present significant differences (p> 0.05) in relation to the weight of the meat, the month of May / 16 presented a mean percentage of R = 14.29. Differences between gonadal stages did not show significant influence (p> 0.05) on oyster meat yield. The analysis of linear correlation, between height and meat yield, shows that in the community, the larger the height of the shell, the lower the meat yield of the animal. In Capanema, 50.22% were females and 45.02% males, 1.73% hermaphrodites and 3.03% of indeterminate sex (n = 231). The analysis of the gonadal stages showed that the reproduction of C. rhizophorae in Capanema is continuous during the year, without an eminent sexual rest period, probably influenced by the small temperature variation in the region. Salinity made sexual characterization difficult during the month of August. The extraction of small oysters, in which the yield in meat is higher, is not indicated for extraction, because it can reduce the reproductive capacity of the populations. The results of this study provide information capable of establishing a minimum height for the extraction of oysters in the natural banks, thus adopting management measures such as rotation of the extraction areas and a system of frequent monitoring of the stock.