Biologia reprodutiva de Plagioscion squamosissimus(Pisces, Sciaenidae) em uma área de proteção ambiental do Nordeste do Brasil

The South American silver croaker it's a specie of great importance for the fishing profitability of Maranhao state, being the target of most of the fisheries of the Environmental Protection Area of Baixada Maranhense. The present work aimed to characterize the reproductive biology of Plagioscion squamosissimus to subsidize fisheries management measures. Fish samples were taken bimonthly during the period from February 2012 to January 2013, totaling 182 specimens. In the laboratory, the biometry of each individual was performed and then a ventro-longitudinal incision was made to macroscopically observation of the gonads. Then they were fixed in Bouin solution for microscopic analysis and in Gilson's solution for analysis of fecundity. The specimens analyzed ranged from 11.5 to 38 cm in total length (TL). Allometry was negative for males and females. The sexual ratio was 1.2F: 1, with no significant difference. The mean length of first maturation was estimated at 15,303 cm. The spawning is synchronous in more than two groups, of the "multiple batch spawners" type. The absolute fecundity was estimated in 143,337 oocytes, characterizing high fecundity. The data obtained in this study showed that the lake of Viana was favorable to the growth and maintenance of P. squamosissimus.