Artificial reproduction in 1-year-old tench (Tinca tinca L.)

Although it is generally accepted that sexual maturity of tench (Tinca tinca L.) is not reached before 2–3 years of age, a successful experiment on artificial reproduction in 1-year-old tench is described. It was possible to obtain semen and eggs from 48% of males and 27.7% females kept in a small concrete tank at a final density of 3 kg m−3 and fed on a commercial dry diet. Two hormonal treatments were applied: the first with 1354 degree-days and the second with 2353 degree-days. In each experiment, the positive response in males and females was around 80%. Total egg production exceeded 11% of body weight, fertilization rate was above 90% and hatching rates around 50%. These results differ little from those reported for older breeders.