Reproductive aspects of common carp (Cyprinus carpio L, 1758) in a tropical reservoir (Amerti: Ethiopia)

The reproductive aspect of common carp (Cyprinus carpio L, 1758) in the Amerti reservoir (9°.63 ’ N, 37°. 23 ’ E) was studied monthly between August 2011 and July 2012. A total of 496 specimens, comprising 231 males and 265 females were captured during the sampling period. There were no significant differences between the sex ratio ( 2 = 2.33; P= 0.126). The mean ± SD of Fulton’s condition factor was 1.22 ± 0.14 for both sexes. The size at first sexual maturity (L50) for male Cyprinus carpio was 27.2 cm fork length (FL) while the females attained L50 at 28.3 cm FL. Absolute fecundity (F) varied between 36955 and 318584 with a mean ± SD of 170937 ± 13084 for the length group (270-470 mm FL). The relationship between F and FL were significant (F=0.224*FL 3.708 , R2 = 0.933; p<0.001). The mean monthly water temperature that ranged from 18.9 to 23.1°C during the study period appears to favor year round spawning of common carp in the reservoir.