a total of 1312 individuais of s. rastrifer were sampled from march 1994 to september 1996 at the guaratuba bay, southern brazilian coast. this species is a permanently inhabitant of the mangrove area throughout the year. the weight/length relationship of the species in the region is "in tw =-12,35 + 3,22 in tl", and the individuais may reach 172mm of total length. the analyses of gonadal morphology and gonadossomatic index indicate that s. rastrifer is a multiple spawner species, that reproduces at the mangrove area during a long period of the year. the reproductive activity is more intense during the winter and mainly the spring, when the value of condition factor declines and empty folheies are found in the ovaries.