Age and growth of Berg Loach (Oxynoemacheilus bergianus) in Kordan River of Namak basin in Iran

Yazdan Keivany

Mohammad Reza Kamaloo

Abstract

The age and growth of Oxynoemacheilus bergianus were examined in 358 specimens collected monthly from Kordan River in 2013–2014. The total length range was 32.36–74.36 mm (50.95 ±10.3 SD), and the total weight 0.31–4.06 g (1.12 ±0.68 SD). The maximum age based on otolith readings was 5+ years for females and 4+ years for males. The most frequent age groups were 2+ and 3+ in males and females, respectively. The total length–weight relation for females was W = 0.0079TL2.99 (r2 = 0.92) and for males was W = 0.0093TL2.84 (r = 0.92), indicating an isometric pattern for females and a negative allometric growth for males. The Von Bertalanffy
growth model was estimated as Lt = 86.9[1-e-0.16(t+3.1)] and Lt = 94.3[1-e-0.15 (t+2.5)] for males and females, respectively. The growth performance index was estimated as 7.1 for males and as 7.2 for females, indicating a faster growth rate for females. The fastest growth rate for this species was in the first and second year of life.