Growth and reproduction of (Capoeta damascina Valenciennes 1842) from the Hanna wetland, Semirum

Abstract

As part of ecological study of Hanna Wetland, Semirum, in Isfahan province, the age, growth, and reproductive characteristics of Capoeta damascina, a major species of the wetland were investigated. A total of 270 specimens were collected by cast net and gillnets of different mesh sizes (5-70mm) during fall and winter 2007, and spring and summer 2008. The ratio of males to females was 1.0: 2.2 (MT). Seven (1+ to n and six (1+ to 6+) year classes were recorded for females and males, respectively. In all class, females were always larger than males. Maximum fork length and weight of 44.2 cm and 1545g for females and 40.0cm and 1300g for males were recorded. The minimum, maximum, and average absolute fecundity were 2203, 36763, and 19121±9503, respectively. According to Gonadostomatic Index (GSI) values, spawning of C. damascina occurs from May to June. The Von Bertalanffy growth parameters fit to size-at-age data were: K=0.136, L. -- 66.96cm, to .0.161 years for females and K=0.174, 1,0,=54.70cm, t, 0.37 for males. The weigh-length relationships were described as W=0.0143L3a0471 (r2 = 0.9597) for females and W=0.009401695 (r2 =7- 0.9768) for males. According to b values obtained, both sexes show a positive allometric growth. The growth performance index 9' was estimated at 7.071 and 6.092 for females and males respectively that indicated a faster growth rate for females.