Population structure and reproduction of Menticirrhus americanus (Linnaeus, 1758) (Teleostei, Sciaenidae) in Ubatuba-Enseada Bay, Santa Catarina, Brazil

Abstract

Population structure and reproductive aspects of the southern kingfish Menticirrhus americanus in Santa Catarina northern coast were investigated. Trawl nets were used for the monthly surveys between October (2003) and September (2004). A total of 425 individuals between 4.2 and 31.8cm (mean 12.7 ± 5.7) were analyzed, and the majority of the individuals (4.2 to12.5cm) was captured mainly in summer, autumn and winter, while larger individuals were captured in spring. Females of all size classes were predominant during summer and winter, and weight/length relationship showed significant differences between sexes and a positive alometric growth for the species. The size at first maturity (L50) was estimated in 16.7cm for females and 15.4cm for males. The reproductive period occurred in warm seasons, and M. americanus showed multiple spawning. The hepatossomatic index demonstrated a similar seasonal pattern as the gonadosomatic index, and was a good indicator of the spawning. The condition factor wasn’t a good indicator of the spawning period, but it was related with the recovery process and gonad maturation. Characteristics of the population dynamic showed that M. americanus utilizes the study area for reproduction and recruitment.

Keywords

• Betara
• Coastal region
• Condition factor
• Reproductive biology