养殖雌达氏鳇的生长、性激素水平和卵巢发育

Growth Characteristics,Sexual Hormone and Ovary Development in Siberian Huso Sturgeon Huso dauricus under Artificial Farming Conditions

本文研究人工养殖条件下雌达氏鳇Huso dauricus的生长、性腺发育以及性激素变化特性。结果表明:随着年龄的增长,雌达氏鳇体质量和体长显著增加(P【0.05),体质量与体长关系式为:W=8E-0.7L3.46,(R=0.99)。不同年龄雌鱼的肥满度随年龄的增加而增加。达氏鳇血清雌二醇(17β-E2)和睾酮(T)水平随雌鱼年龄的增加而升高,9龄雌鱼血清的17β-E2和T水平显著高于2~8龄雌鱼,分别为36594.4pg·m L-1和77.97ng·m L-1(P【0.05)。2~9龄达氏鳇血清的E2/T比值的变动范围为0.283~0.469,而6龄雄达氏鳇血清的17β-E2/T比值则为0.014。其中,6龄雄性达氏鳇血清的T水平显著高于2~7龄雌鱼(P【0.05),而与8龄雌鱼血清的T水平差异不显著(P】0.05)。组织学观察显示,2~3龄达氏鳇的性腺已发育至第Ⅰ期,其中4~5龄雌鱼的卵巢以第Ⅱ期时项的卵母细胞为主,而6~7龄的卵巢以Ⅲ时项的卵母细胞为主,8~9龄达氏鳇的卵巢以Ⅲ期末的卵母细胞为主。

Body weight, body length, serum sex steroid levels and ovary development were monitored in Siberian huso sturgeon Huso dauricus from 2 years old to 9 years old under artificial conditions in order to understand the growth characteristics, change of level in serum steroid and ovary development of Siberian huso sturgeon. The body weight and body length was shown to significantly increase with age (P<0.05), and the relationship between body weight (W) and body length (L) was expressed as W=8E-0.7L3.46(R=0.99). The condition factors were found to be increased with age in Siberian huso sturgeon, and the levels of serum 17β-E2 and T in female were increased with age, higher in 9 years old fish(17β-E2 value of 36594.4 pg·mL-1 and T value of 77.97 ng·mL-1) than in other years old fish(P<0.05).The serum E2/T value was changed from 0.283 to 0.469 in females, and very low in males(0.014). The histological observation revealed that the ovary with stageⅠ, which there are more oogonia, was observed in 2 years old and 3 years old Siberian huso sturgeon. The stageⅡovary leading by primary oocytes was found in the 4 years old or 5 years old Siberian huso sturgeon. The 6 years old and 7 years old females had the stageⅢovary dominated byⅢphase oocytes. When the fish has grown to 8 or 9 years old, the ovary was primarily consisted ofⅣphase oocytes.