The Morphological Characteristics And Gonad Development Of The Multiple Pengze Crucian Carp And RAPD Analysis Of The F₂ Generation

Pengze crucian carp (Carassius auratus of Pengze), is an endemic bisexualpopulation with natural gynogenetic reproduction mode. The multiple pengze cruciancarp is the minority of the offspring of Pengze crucian carp activated by heterogenoussperm, which grow speed also obvious compare it quickly than Pengze cruciancarp,and possesses some obvious patrilineal characteristics, for example the length ofrostrum, the apophysis of the back and the color of the lateral scales and so on.In the thesis, traditional morphological data and truss network data were used tostudy the morphological variations of multiple pengze crucian carp and Pengzecrucian carp. Method of dissection and histological obsevervation were used to studythe process of ovary maturation of the multiple pengze crucian carp on celllevel, complement the content of reproductive biology of multiple pengze cruciancarp, including the annul cycle of gonad development, the process of oogenesis and thediffearse in developing process of the oocytes in different phase of ovary. Randomamplified polymorphic DNA (RAPD) technique was used to anaiysis the F₂generation of multiple pengze crucian carp on DNA level, discusse the developmentmode of multiple pengze crucian carp.Major results were :(1)In the aspect of meristic characters, there were nosingnificant differences between the multiple pengze crucian carp and Pengze cruciancarp. In the aspect of traditional measurable characters plus truss networkcharacters, there were significant differences between them. Principal componentanalysis indicated that morphological differences between the tow strains were:headlength, backside depth, origin of pelvic fin, length of caudal peduncle, epth of caudalpeduncle, length between anal fin and caudal fin, length between ventral and dorsalorigin of caudal fin. Some simple discrimination formulas were produced todistinguish multiple pengze crucian carp form Pengze crucian carp.(2)The gonadaldevelopment of multiple pengze crucian carp was similar to that of common carp andcould be divided into six stages. The female fishes attained sexualmaturity when they were about one years old. The diameter of mature oocyte was 293.6～317μm. Thebreeding season of multiple pengze crucian carp was form March to May. This studyprove that the gonadal development of the multiple pengze crucian carp was nomaland both the female and the male fish could bu fertile. (3)The tow offsprings of themultiple pengze crucian carp, actived by maternal(Carassius auratus of Pengze) andpaternal(sea carp) sperm respectively, mostly amplified the same band patterents witheach other.Those above result shows that:(1)Principal component analysis showed that therewere highly significant differences between multiple pengze crucian carp and Pengzecrucian carp. The morphological differences mostly due to variations on the frontalpart of the body and the caudal fin depth. (2)The gonadal development of multiplepengze crucian carp was similar to that of common carp and could attain sexualmaturity in one year. (3)The multiple pengze crucian carp inherite the characteristic ofgynogenesis form its female parent(Carassius auratus of Pengze), basically, differentsperms had no effect on the development mode of multiple pengze crucian carp.