A comparative study on some biological parameters in broodstock and juvenile kutum, Rutilus kutum in the southern Caspian Sea basin

摘要

Some biological characteristics of broodstock and juvenile kutum, Rutilus kutum. were investigated using data collected from the estuaries of Tajen and Shirood Rivers (TR and SR) (south Caspian Sea basin) as well as from the Caspian Sea in 2012. The results showed higher condition factors (CF) in the male broodstocks than those estimated in the female broodstock of both TR and SR. The female juveniles displayed a greater level of CF. The Von Bertalanffy's growth equations were calculated as: Lt = 40.67(1 – e−2.27(t−18.84)) and Lt = 50.11(1 – e−0.48(t+1.814)) for the broodstocks of SR and TR, respectively, and for the juveniles as: [Lt = 48.36 (1 – e−0.537 (t+ 0.913]. The males of SR presented a negative allometric growth pattern.The females and males of both SR and TR presented similar isometric growth patterns. Both male and female juveniles from TR exhibited a positive allometric growth pattern. The calculated equations for total length and weight were as: W = 3E−06 L3.2069 and W = 5E−07 L3.4745 for the male broodstock of SR and TR, respectively, and as: W = 5E−07 L3.4745 for the juveniles. The measured parameters may reflect the role of fish habitat characteristics such as food availability, population density, and age classes depending on sex and season.