Biology of Paralonchurus brasiliensis (Steindachner) (Teleostei, Sciaenidae) in Paraná coast, Brazil

Abstract

The populational structure, reproduction and feeding features of banded croaker in southern coast of Paraná State are presented. Samplings were performed through bottom trawl from March 1999 to January 2000 at depths 10 and 15 m. Paralonchurus brasiliensis is more abundant during spring, when the youngest individuals, smaller than 93 mm, are recruited. The relation weight/length for grouped sexes is TW(g) = 2.74E-6TL(mm) 3.22 (n = 659; R2 = 0.99). Gonadal maturation is recorded since the length class 130-165 mm and the average length of the first maturation (grouped sexes) is estimated in 175 mm. Sand worms (Polychaeta) are the feeding item more usual for the all size classes and seasons, followed by crustacean and fishes. Species reproductive period extends from autumn (start maturation) to summer (end the spawning). After spring, youngs probably leave the area 10 m of depth. The prohibition of the shrimp bottom trawl in this depth during the spring and the summer must be efficient to reduce P. brasiliensis by-catch, today composed by recruits or spawning proximity individuals.