The present study seeks to elucidatc reproduetive aspects of Sphoeroides testudineus (Linnaeus, 1758), Tetraodontidae. Monthly collections were accomplished for one year (November/98-October/99), in the gamboa do Baguaçu, Bay of Paranaguá with a Fyke net. The macroscopic analysis of the gonad stages allowed us to estimate the sexual proportion as 1:1 during the whole period, except in the months of May and October, when the proportions of two females for one male and two males for one female were observed respectively. The analysis of the relative frequency of the monthly gonad stages and the Curve of Maturation aided in the determination of the reproduetive period, that oceurred from September to January. Microscopic analyses of the female gonads allowed us to characterize four develo-pment phases of the ovarian follicle, six stages of ovarian development and the type of spawn, which was parceled. The first maturation for females was estimated to be betwecn 10-11 cm of length.
Tetraodontidae; puffer fishes; reproduetion