English abstract
The goldlined seabream Rhabdosargus sarba (Forskål, 1775) is farmed in several countries of the Western Pacific Rim and is a candidate species for aquaculture in the Gulf States of the Middle East. This study was undertaken to examine the onset and patterns of maturity in male goldlined seabream in support of the development of practical hatchery techniques. The testes of 337 male fish (0 + to 7 + , average FL 183 ± 20 to 315 ± 12 mm) collected from the Oman trap fishery (August 2001-April 2002; September 2002-2003) were classified into four stages, based on cell type (immature, developing, active or resting). Four spermatogenetic cell types were identified in the testes spermatogonia (types a and b), spermatocytes, spermatids and spermatozoa. Active testes appeared more regularly during the peak of the reproductive season in January and February. In March, resting testes were observed indicating the end of the reproductive season. There was clear evidence of protandry. Intersex gonads were observed in male fish from age 0 + to 7 + (33% at age 0 + to 75% at age 7 + with maximum 82% intersex frequency observed at age 5 + ). From the evidence presented, male fish age 1 + produced free-flowing sperm under slight abdominal pressure during the period November-March.
