Study On The Biological Characteristics Of F₁ Hybrids Ocolour Crucian Carp And Cyprinus Carpio Var.jian

Six experiments were concluded to explore the biological characteristics of F1 hybrids of colour crucian carp and C.carpio var.jian. The Japanese colour crucian carp and C.carpio var.jian,the parents, were introduced from Luoyang, Henan Province and Wuxi, Jiangsu Province respectively. On 23, April, 2013, the strong and healthy parents were selected out and injected with human chorionic gonadotropin, luteinizing hormone-releasing hormone oxytocin and domperidone. The parents spawned and mated at around 2: 30 a.m. on 24, Aprial, 2013, when the water temperature in hatchery was controlled at 28-30℃. Then we got jian carp F1(C.carpio var.jian ♀ × crucian carp ♂) and carp jian F1(color crucian carp ♀ × C.carpio var.jian♂) generation. The fish were farmed in the laboratories and experimental farms of Research Institute of Aquaculture of Shihezi University.The study included the following six parts, the first part of is to study F1 hybrid morphology; the second part is to study F1 hybrid morphology; third part is to study the morphological characteristics of F1; the fourth part is to study F1 hybrids morphological characteristics; the fifth part is to compare the meat quality between F1 hybrids and parents; the last part is to primarily study the F1 hybrids germ cell chromosomes.The test one sampled 50 individuals respectively from the University and the Fisheries Research Institute. The body measurements, the countable properties data and the condition factor were analyzed and compared. In the test two the number of melanocytes on a scale was counted under a microscope and OD(optical density) values of crucian carp Carassius auratus and Jian common carp Cyprinus carpio var. Jian reared in indoor aquaria and earthern ponds for 6 months.The test three respectively chose 50 individuals from the Jian carps, the colorful carps, the F1 hybrids of the colorful carp(♂) and the Jian carp(♀) and the F1 hybrids of the colorful carp(♀)and the Jian carp(♂). The fish in each group had similar age in days. Each group chose five fish which had the similar weight to measure the intestines length and intestines weight and then made intestinal biopsies. And we calculated the indexes of intestinal weight and length and the height of duplicatures and other data. We disposed data by the Excel and analyzed data by the LSD of SPSS(17.0). The test four sampled 5 individuals respectively to determine the numbers of intraepithelial lymphocyte of foreguts,midguts and hindguts. We also determined the index of intestine length,the index of intestine weight,the spleen index and the hepatopancreas index.The test five sampled 3individuals respectively.We concluded from analyzing and comparing the p H value, the drip loss,the cooking holding percentage,the diameter of muscle fiber, the density of muscle fiber and the myofiber area. In the Experiment 6, 20 fish were randomly selected from each four types, then their testes or ovaries were removed and put into a petri dish filled with saline in 0.8% Na Cl andcut into pieces with scissors. Then they were put into centrifuge tube and were struck. After the standing, the cell suspension was taken out. Then 1000 rpm centrifugal for 5min; supernatant; the collected cells were suspended in 0.075 mol / L KCL hypotonic in hypotonic 2-5h, which repeatedly pipetting; centrifugation, the cells were collected; in methanol and glacial acetic acid(3:1) mixture fixing, fixing is repeated 2-3 times; the frozen droplets slide sheet, a flame-dried;Giemsa dyed. All the subjects’ gonad was observed in terms of histology. After fixed in Bouin’s solution for 1-2d, the gonad was dehydrated level by level in ethanol, embedded in paraffin and HE stained. Chromosomal and gonadal development were observed under a microscope, using NIS-Elements D digital microscope camera system. The main results are as follows:(1) The index body length/overall length of the F1 hybrids of the colorful carp(♀) and the Jian carp( ♂) tended to the female parent and the index withers height/body length of the F1 bybrids of the Jian carp(♀) and the colorful carp(♂) tended to the female parent, that the indexes head height/withers height, head height/head length and caudal peduncle length/caudal peduncle height all tended to the Jian carp and that the index head length/body length tended to the hybrid trait.(2) The OD value of the hybrids(Carassius auratus♀×Cyprinus carpio var.Jian♂) was close to the Carassius auratus(P>0.05).The numbers of black pigment cells of the hybrids(Carassius auratus♀×Cyprinus carpio var.Jian♂) were extremely significantly less than Cyprinus carpio var.Jians’(P < 0.01). The values of red pigment cells of the hybrids(Cyprinus carpio var.Jian♀×Carassius auratus♂) were extremely significantly lower than the Carassius auratuss’(P < 0.01). The numbers of black pigment cells of the hybrids(Cyprinus carpio var.Jian♀×Carassius auratus♂) were significantly less than the Cyprinus carpios’(P < 0.05).(3) The rate of digestion of the F1 hybrids of the colorful carp(♂) and the Jian carp(♀)were higher than the rate of digestion of the F1 hybrids of the colorful carp(♀) and the Jian carp(♂) and that the digestion rate of the F1 hybrids of the colorful carp(♂) and the Jian carp(♀) is higher than that of the two kinds of parental generations.(4) We concluded from analysis and comparison that there was significant distinction of intestinal length index, intestinal index, spleen index as well as liver and pancreas index between F1 hybrids and the parents. All the indexes of F1 hybrids were higher than those of parents’.Colour crucian carp parents and Cyprinus carpio Var.Jian parents have more Intestinal epithelial lymphocytes than F1 hybrids.(5) The results showed that the p H value, the drip loss, the cooking holding percentage, the density of muscle fiber and the myofiber area of the two kinds of hybrids were lower than the parental generation.But the diameter of muscle fiber of the F1 hybrids of the colorful carp(♀)and the Jian carp(♂) was minimum.This showed that its meat quality was the best.(6) Because the subjects were only 12 months old, which means they have not reached sexual maturity, the ability to achieve fertility status after full sexual maturity could be tested. Theovary slices showed that the eggs in the early primary oocyte were normal, though its fertility could not be confirmed. The testis slices showed that spermatocytes, fine vesicles, Leydig cells,Sertoli cells were in a normal state, and there were a large number of sperm cells. However, due to the sexual immaturity, the sperm cells showed no metamorphosis, hence unable to determine the possibility of the cells to become fertile sperm.The results suggested that:We infer that the discrete growth performance occurs and the gene controlling the body color is from the female parent. The gut mucosal immunization of the hybrids between their parents but the growth performance of internal organs of the hybrids was better than their parents’. And this reflected hybrid vigor. The parental generations’ meat are more tender and the edible quality is better than the offsprings.