| To further promote artificial breeding technology of Hucho taimen, it was important to systematically study the characteristics of its physiological breeding, nutritional needs, since realized the successful artificial breeding not very long time. The nutritional changes during embryonic and larval development, vitellogenin (Vg) of physical and chemical properties as a major nutrient, temperature on the larvae growth were discussed, and some meaningful results were obtained.The composition of proteins, lipids, amino acids and fatty acid were examined by biochemical methods during embryonic and larvae development. (1) From egg to first-feed larvae stage the content of both protein and total amino acid showed a downward trend in general, but during gastrulation and eyeball pigment stage showed a significant pick-up, followed a sharp decline by yolk sac larvae and first-feed larvae stage. Leucine (Leu) was the highest essential amino acid at egg stage and lysine (Lys) was the highest essential amino acid at first-feed larvae stage; moreover, glutamic acid (Glu) was was the highest non-essential amino acid and cystine (Cys) was the lowest amino acid from egg to first-feed larvae stage. (2) The highest fat content was in the yolk sac larvae stage, followed by first-feed larvae stage, but there was no significant differenc between egg and first-feed larvae stage (P>0.05): Saturated fatty acids (SFA) as the main embryo and larval development energy provider, its content appeared a downward trend, of which C18:0 had the largest proportion during different developmental stages and dropped the largest amount; The total amount of monounsaturated fatty acids (MUFA) increased significantlly, only C16:1n-7 balanced. The total amount of polyunsaturated fatty acids (PUFA) also increased significantlly, however, there was no significant difference among fertilized eggs, cleavage and first-feed larvae stages (P>0.05), only 22:6 n-3 (DHA) levels had been declining.Vitellogenin as both major nutrient and female–related protein in serum and egg yolk (FYSP) was purified from untreated Hucho taimen by chromatography and electrophoresis, and its physical and chemical properties were analyzed.(1)The results showed that the second peak's protein of crude extract in eggs was FYSP in eggs, and the characters is identical with FYSP existed in female Hucho taimen serum. After SDS-PAGE, the two kinds of FYSP appeared as three bands and molecular weights of bands were137.8KDa,84.2KD and 10.8KDa. They could be stained by red oil O, Molecular Proes'Pro-Q? Emerald 300 Glycoprotein Gel stain and Pro-Q? Diamond Phosphoprotein Gel Stain, which meant that they are phospholipins-glycoprotein. The PI of FYSP in egg yolk was 5.60. (2) Western-blotting and immunodiffusion indicated that antiserum against FYSP cross-reacted with Female serum of Taimen, but not cross-reacted with male serum.The growth characteristics of Hucho taimen larvae were studied at different temperatures(12℃, 15℃, 18℃, 21℃, 24℃) by aquarium. (1) there were significant differences in the results among five temperature groups, of which 12℃, 15℃, 18℃three temperature groups growed healthy; 21℃group in varying degrees diseased after 30~49 days breeding; 24℃group had acute death in the initial culture. Besides the larger difference among temperature groups, there were also large differences between individuals in the same temperature group, 21℃group had relatively large differentiation between individuals, but 12℃, 15℃, 18℃groups little differentiation and growth is relatively tidy. (3) When at 12~18℃, the growth rate of hucho taimen larvae is accelerated with increasing temperature, and 18℃reached the highest, 21℃was the maximum temperature for growth additionally. |
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