Reproductive biology of Menticirrhus littoralis in southern Brazil (Actinopterygii: Perciformes: Sciaenidae)

Abstract

Menticirrhus littoralis is an important sport and commercial fish species in southern Brazil. This paper aims to analyze the reproductive biology of the species in Rio Grande do Sul coastal waters. Captures were carried out at Cidreira's fishing pier (30º 08' S; 50º 11' W) located on the Northern Coast of Rio Grande do Sul, where sport-fishing takes place throughout the year. Sport fishermen using hook-and-line with different hook sizes and varied baits exclusively made the captures. A total of 807 individuals were obtained from June 1997 to May 1998. Sexual proportion was 0.67 female for each male (323 females and 484 males; chi2c = 32.120; DF=1; P<0.001). The smallest individual (total length) for captured animals was a male of 13 cm whereas the largest was a female of 46 cm. The minimum size (total length) for a mature female was 19.8 cm. The size at first maturation (L50) was 23 cm and females larger than 27 cm spawned at least once (L100). The reproductive period for M. littoralis is from September to March. Gonadosomatic index (GSI) showed a clear seasonal pattern. Mean ovarian weight was highest in November when it reached 5% of total body weight. Apparently, there is a size gradient for M. littoralis in the area. Larger individuals inhabit deeper water, and they move to the coast mainly for spawning.