Induced Reproduction of Aphanius fasciatus by Ecophysiological Conditioning and Hormonal Treatment in Fresh and Marine Water

Abstract

The Mediterranean toothcarp (Aphanius fasciatus) can be used to biologically control mosquito larvae. The reproductive performance of 234 Mediterranean toothcarp (180 females and 54 males) was investigated. Reproductive factors were determined in fish kept in fresh or saline water (males and females together), and in fish kept separately by sex in saline water and hormonally-treated with carp pituitary extract (CPE). In the hormonally-treated group, the combined effect of temperature, photoperiod, and hormonal treatment induced the best ovary maturation and larvae production rates. The rate of reproduction was very high (average eggs/female: 5.9-10.5) compared to natural reproduction in the wild (average eggs/female: 2-4). Additionally, the hatching rate was 97-100%. The results of this study show that reproduction of Mediterranean toothcarp can be controlled in an artificial environment: the lack of mortality in adults during acclimation and conditioning in fresh and marine waters indicates good domestication and plasticity in reproductive parameters.