Fertilization Biology And Reproductive Mode Studies Of Pingxiang Red-transparent Crucian Carp (Carassius Auratus Gibelio Bloch)

The basic biological characteristics, main events of fertilization biology and reproductive mode of Pingxiang red-transparent crucian carp (Carassius auratus gibelio Bloch) was studied. Three main achievements were obtained in this dissertation.1. Though feeding on varieties of food, it was found that both Brachionus forficula and Paramecium sp. were fit for the initial feeding of Pingxiang red-transparent crucian carp larvae; Data about the growth of artificial breeding populations at six offspring were collected. We made a conclusion that the body weight and length rose, male-to-female ratio of selective population were higher than the wild ones.2. The sperms of Xinguo Red Carp (Cyprinus carpio var. singuonensis) and Pingxiang red-transparent crucian carp penetrating into the eggs of the Pingxiang red-transparent crucian carp were observed by scanning electronic microscope. The results indicated that there were no remarkable differences in the process of sperms penetration into eggs between crossbreeding and inbreeding. While mature eggs and sperms meeting, activated mutually, and resulted in a series of response, such as cortical reaction, fertilization membrane hunching, maturation division restarting with the extrusion of a single polar body, the plasma membrane restoration and reorganization. In addition, the earlier embryogenesis processes of crossbreeding and inbreeding were observed directly by common microscope. The results showed that the modalities of embryos of crossbreeding and inbreeding looked the same, but there was a little difference on the time of early stage of embryogenesis.3. The cytological observation on the fertilization of Pingxiang red-transparent crucian carp ( ♀ ) × Xingguo re common carp (♂) and Pingxiang red-transparent crucian carp ( ♀) × Pingxiang red-transparent crucian carp (♂) were carried out, and the results showed that heterologous sperm nucleus remained as a condensed mass and could not transform into male pronucleus, while homologous sperm could partlytransform into male pronucleus and amphimixis could be observed. Karyotype of head kidney tissues and the patterns of four isozymes (EST, LDH, MDH and G-6-PDH ) were investigated in hybrids and purebreds, and the results indicated that there were no differences between the two kinds of offspring. The Fi progeny of the Pingxiang red-transparent crucian carp triggered by heterologous and homologous sperm was analyzed by SSR. The amplified patterns clearly indicated that the Fi progeny triggered by the red carp was similar to mother but different from father.In conclusion, Pingxiang red-transparent crucian carp (Carassius auratus gibelio Bloch) as a multiple triploid and bisexual reproductive strain did reproduce by both gynogenesis and bisexual.