Reproductive Biology and Larval development of a Gizzard Shad, Nematalosa erebi (Gunther) (Dorosomatinae: Teleostei), in the River Murray, South Australia

Abstract

The reproductive biology of the native Australian bony bream, Nematalosa erebi, resembles that of other gizzard shads. In the lower River Murray the species matures in its second or third year, spawns independently of flooding in December-January at temperatures of 21-23º C, and is highly fecund. Reproductive output increases with size. The ova and larvae are small, the yolk sac stage is brief, and development is typical of clupeids except for the fin-ray sequence. Sexual dimorphism does not occur, but females predominate in the largest size-classes. Catches of bony bream are increasing where other native species are in decline. This may indicate that bony bream larvae are not dependent on flooding for food, or that the species has an exceptional capacity for rapid population recovery.