Life history and other biological traits of the trout barb Capoeta trutta in the River Meymeh (western Iran)

The trout barb Capoeta trutta is native to the Middle East only and little is known of its life-history in Iranian waters. Life history characteristics were examined in 366 specimens collected from the River Meymeh (western Iran) monthly during the reproductive seasons (March-May) of 2008 and 2009. Observed maximum age was 6+ years in both sexes, sex ratio (male : female) was 1 : 1.35, and length-weight relationships were TL = 0.0266TW2.7134(males), TL = 0.0258TW2.7251 (females), and TL = 0.026TW2.7217 (entire population). Mean egg diameter (ED) was 1.61 (± 0.03 SE), ranging from 1.6 to 1.9 mm. Mean absolute (AF) and relative fecundity (RF) were 7594 (± 283.04 SE) eggs/female, and 70 (± 241.86 SE) eggs·g-1 body weight, respectively. AF and ED were found to increase significantly with increasing fish size, whereas RF decreased significantly with both fish TL and weight. Simplified von Bertalanffy growth estimates were also calculated.