Reproductive biology of the large scale barb, Capoeta aculeata (Valenciennes, 1844) in Gizehrud River, Tigris basin, Iran.

Capoeta aculeata (Valenciennes, 1844) is native to Iran and little is known about its biology. Some biological characteristics of this species were examined in 120 male and 257 female specimens collected monthly from the Gizehrud River of Lorestan Province (Tigris basin, Iran) during July 2014-June 2015. The maximum age of the specimens, based on scale reading, was 6+ years for both males and females. The most frequent age group was 4+ in both sexes. Fork length ranged from 12.2 to 20.8 cm (17.4±1.2SD) and weight ranged between 32-188 g (93.6±21.8SD). Sex ratio was 1M:2.1F. Based on macroscopic gonad observation, maturation cycle consisted of four stages: Developing, spawning, regressing and regeneration phases. The GSI index indicated that reproduction of C. aculeata in Gizehrud occurred between April and May, with the highest value average of 6.37 for males and 11.91 for females in May. Oocyte diameters ranged from 0.57 to 1.88 mm, with a mean value of 0.87 mm. Absolute fecundity ranged between 3000 and 19500 (8300±3400) eggs. Absolute fecundity and fish size (fork length and total weight) were moderately correlated. Relative fecundity varied from 50 to 140 (80±20) eggs per gram of total body weight. This fish is a synchronous spawner. [ABSTRACT FROM AUTHOR]