Hydrostatic pressure shock induced diploid/tetraploid mosaic in mandarin fish (Siniperca chuatsi), with the observation of embryo development and change in body spots

Abstract

The mandarin fish, Siniperca chuatsi, is an economically fish with delicious flesh and rich nutrients. Artificially induced polyploid is an effective methods of breeding superior species of fish. The increasing frequency of mosaicism in the research of fish polyploidy has attracted the attention of many scholars. In this study, hydrostatic pressure shock caused an abnormal cleavage of fertilized, larvae treated with pressure shock displayed reduced fertilization, hatch and survival rates. Mosaics that both have diploid and tetraploid cells were induced in mandarin fish. The effective condition was applying 500 kg/cm2 pressure at 45 min after fertilization for 2 min at 25 °C, the occurrence of 44.5% diploid/tetraploid mosaic fish was confirmed by flow cytometry determination of DNA content. Mosaic mandarin fish has the ability to incubate and grow, and the body weight and body length analysis showed no significant difference between mosaic and diploid individuals. However, after the hydrostatic pressure shock, delayed embryonic development and body deformities were observed, and the body spot and stripe have largely changed in experimental mandarin fish.