【作者】 陈静；

【导师】 朱邦科； 梁银铨；

【作者基本信息】 华中农业大学 ， 渔业资源， 2008， 硕士

【摘要】 匙吻鲟(Polyodon spathula)是目前世界上匙吻白鲟科仅存的两种之一,另一种是分布于我国长江中的白鲟。《濒危野生动植物种国际贸易公约》(CITES)附录Ⅱ保护物种,该物种目前处于易危状况。我国于1990年开始从美国引进匙吻鲟,迄今关于匙吻鲟的资料仅有零星的养殖技术资料方面的报道,对该种鱼在早期生活史和营养学方面的报道甚少。本文对匙吻鲟早期发育和不同生长阶段体成分进行了研究,主要研究结果如下:1.匙吻鲟的成熟卵为多黄卵,卵裂为特殊的辐射裂。匙吻鲟的胚胎发育可分为9个发育阶段:受精卵、卵裂期、囊胚期、原肠期、卵黄栓期、神经胚期、心脏搏动期、孵出前期和孵出期。在水温为18～22℃(平均20℃)时,匙吻鲟胚胎发育需要119～138 h,总积温为2266～2617℃·h.。刚孵化出来的仔鱼全长为7.38 mm。2.在水温为18～22℃(平均20℃)的条件下:早期仔鱼(日龄0～8d)卵黄囊吸收完全,平均全长7.38～15.50mm;晚期仔鱼(日龄8～22d)吻端有色素沉着,体透明的特征逐渐消失,鳍条开始发育,仔鱼平均全长15.50～31 mm;稚鱼期(日龄22～71 d)各鳍条发育完成,尾鳍分叉,平均全长为31～230mm。3.饥饿仔鱼身体消瘦,停止增长或出现负增长,器官停止发育,脑后部下陷,游动缓慢,身体失衡。在水温19～23℃(平均21℃)时,仔鱼在日龄为17.5 d时达到PNR点,在仔鱼日龄为17 d期间,瞬时死亡率达到49.25%,总死亡率为85.71%,随后日龄为19 d的仔鱼,瞬时死亡率和总死亡率都为100%。4.不同生长阶段的匙吻鲟肌肉成分分析表明,体重为50 g,150 g,300 g,600g的水分含量依次降低,蛋白质和脂肪的含量依次升高。蛋白质含量分别为13.17±0.54%,15.71±0.23%,16.77±0.39%,17.09±0.28%,脂肪含量分别为1.75±0.14%,2.21±0.30%,2.72±0.24%,3.10±0.13%。氨基酸总量与鱼体内蛋白质含量趋势相同,都是随着体重的增加,氨基酸含量增高,匙吻鲟肌肉中谷氨酸、赖氨酸、亮氨酸、天冬氨酸、甘氨酸和丙氨酸的含量都较高。更多还原

【Abstract】 Paddlefish（Polyodon spathula） populations is now threatened,and it is listed in the AppendixⅡof the Convention on International Trade in Endangered Specied of Wild Fauna and Flora（CITES）.P.spathula was introduced into China from America in 1990. At present,there are only several reports about culture technology of P.spathula,and sporadic reports about early life history and nutritional studies on P.spathula.This experiment was conducted to observe the early development and body composition of larvae and juvenile P.spathula.The main results were generalized as follows:1.The fertilized eggs of P.spathula was megalecithal,and the cleavage of eggs was the speical spokewise cleavage.The whole embryonic development of paddlefish can be divided into nine periods:fertilized eggs periods,cleavage periods,blastula periods, gastrula periods,yolk plug periods,neurula periods,heat beating periods,pre-hatching periods and hatching periods.Under water temperature of 18～22℃（Average 20℃）,the embryonic development lasted for 119～138 hrs.The total accumulated temperature was 2266℃·h～2617℃·h.The total length of newly hatched larvae was 7.38 mm.2.When water temperature was 18～22℃（Average 20℃）,In the early-larvae stage the yolk sac of the larvae was absorbed completely at the 8^th DAH（day afer hatching）,the total length of larvae was 15.50 mm.In the late-larvae stage（8～22 DAH）,the snout of the larvae protruded forward and became dark gradually due to pigmentation,the fins began development,the average length of larvae was 7.38～15.50 mm;In the juvenile stage（22～71 DAH） the average length of larvae was 230 mm,all fins completed their development and the caudal fin completed bifurcation.3.Starvation will result in the stunt growth and organ differentiation.Starved larvae was thin,the posterior cerebral caved,the body unbalanced,and swam slowly.When water temperature was 19～23℃（Average 21℃）,the starved larvae reached their PNR （the point-of-no return） at 17.5 DAH.At 17^th DAH,the total mortality of starved larvae was up to 85.71%and its instantaneous mortality was up to 49.25%.At 19^th DAH,both total and instantaneous mortalities of starved larvae were up to 100%.4.As the juvenile paddlefish grow,its protein content and fat content in the muscle increase significantly while water content decrease.When the body weight is 50 g,150 g, 300 g and 600 g,the protein content in its muscle is 13.17±0.54%,15.71±0.23%, 16.77±0.39%and 17.09±0.28%,respectively,and fat content,1.75±0.14%,2.21±0.30%, 2.72±0.24%and 3.10±0.13%,respectively.The amino acid content has the same tendency as protein content,increasing with the increase of body weight.The content of Glu,Lys, Leu,Asp,Gly and Ala was high in the muscle of paddlefish.更多还原