Population structure of Diapterus rhombeus (Cuvier, 1829) (Perciformes, Gerreidae) in the estuarine environment of the state of Espírito Santo

The Family Gerreidae consists of demersal fish, widely distributed in coastal regions and is considered one of the most representative families in tropical estuaries. Diapterus rhombeus is one of the representatives of this family on the Brazilian coast, characterized by small individuals found in sandy bottoms and gravel or mud bottoms, up to about 70 meters deep. This study aimed to characterize the population structure of Diapterus rhombeus in the estuary of Barra Nova/ São Mateus, northern region of the state of Espírito Santo, in order to provide data as a basis for future research, management and conservation of this species. Monthly samplings collected 414 individuals from August 2011 to July 2012, using a bottom trawl. The total length ranged from 4.7 to 19.3 cm. The overall sex ratio indicated predominance of males, with 1.6 males for each female. The L50 for males and females was 14.4 cm and 14.6 cm, respectively. The present study allowed to verify the great ecological importance of Barra Nova for D. rhombeus with regard to its life cycle, including from the time of recruitment of juveniles to the reproduction in the estuarine environment.