Biology of the sea-bob shrimp from the Espí­­rito Santo coast, Brasil

Abstract

The size at first maturity, reproductive cycle, sex ratio and recruitment of the sea-bob shrimp Xiphopenaeus kroyeri were studied from monthly samples in two coastal areas of the Espí­­rito Santo state between 2003 and 2004 in order to support sustainable management of this species. The samples were obtained with bottom trawls in small artisanal fishing boats from 4 to 8 m deep. A total of 6,006 specimens were captured, being 2,766 females, 3,182 males and 58 of undetermined sex. Females were significantly bigger than males. The average length of first maturation of females was 9.026 cm. Adult females predominated over males between December and February, coinciding with the spawning peak, while males predominated in the subsequent quarter. This alternation of proportions was associated with bathymetric migrations of reproductive females. The annual gonadal maturation cycle, seasonal abundance and sizes and recruits suggest the existence of continuous spawning and recruitment in December-February and in July and August. The difficulties of establishing a closed season in proper condition indicated that the management of the resource should receive more attention because of the issues involved, whether social, biological or environmental.