【摘要】 对初始孵化到孵化后26 d(变态前)的圆斑星鲽(Verasper variegatusTemminck et Schlegel)仔鱼的消化系统发生进行形态学和组织学研究。研究表明,在水温为12.5~15.5℃时,初始孵化仔鱼消化道细而直,两端封闭,位于卵黄囊背方。随着仔鱼发育,消化道延长,肝胰脏出现。孵化后6 d,仔鱼开口,消化道贯通,开始摄食。孵化后10 d,消化道明显分为口咽腔、食道、胃、小肠、直肠,黏膜上皮褶皱增多。孵化后14 d,卵黄囊消失,仔鱼完全依靠外源性营养。孵化后26 d,胃壁较厚处出现胃腺,但不发达,幽门盲囊尚未出现。由结果可见,孵化后6 d仔鱼开口,可开始投喂轮虫;孵化后26 d,消化系统的结构和功能逐渐完善,消化吸收能力增强,但由于胃的结构和功能尚不完善,此阶段还应以活体饵料为主,一方面可逐渐加大轮虫的投喂量,另一方面可适当投喂较大的卤虫无节幼体等。本研究旨为圆斑星鲽人工育苗中饵料种类及投喂时间的选择提供理论依据。[中国水产科学,2006,13(1):1-7]更多还原

【Abstract】 Verasper variegatus Temminck et Schlegel is a species of marine flounder commonly named spotted halibut and inhabits sandy and muddy bottoms in coastal areas of the east of China,the central of Japan and the southwest of Korea.As a valuable commercial species,Verasper variegates is a promising candidate for marine aquaculture.A few studies have been conducted on the digestive system of a number of flatfish species such as Paralichthys olivaceus and Scophthalmus maximus.But the knowledge of the development of the digestive system in Verasper variegates is not available.In this paper the development of the digestive system was studied morphologically and histologically in larval Verasper variegatus from hatching to the 26th day after hatching(DAH).The aim of this study was to achieve a better understanding of their organization and functionality which may help synchronize the stage of development with the rearing technology and feeding practices,and to provide a basis for future nutritional and physiological studies during larval rearing.Specimens for this study were maintained at 12.5-15.5?℃.The digestive duct was a straight tube lying dorsal to the yolk sac at the newly hatched larvae(0 DAH),while the mouth and anus were not opened.With the development of the larvae,the digestive tube lengthened and accessory glands(liver and pancreas) appeared.Mouth was open on the 6th DAH.With mucosal fold increasing,the digestive tract was obviously segmented into buccopharynx,oesophagus,stomach,intestine and rectum on the 10th DAH.The yolk sac disappeared and the larvae depended on exogeneous feeding completely on the 14th DAH.On the 26th DAH gastric glands in the gastric wall appeared but were underdeveloped and the pyloric caeca were not found.The above results indicated that the larvae may intake food at the time of mouth opening and on the 26th DAH the stomach was not completely functional although the digestion function of the digestive system was gradually strengthened during larvae development.So it was suggested that the larvae could be weaned to rotifer on the 6th DAH and it was suitable to feed larvae prior to metamorphism on live food including Rotifer and Artemia nauplii rather than artificial diets.[Journal of Fishery Sciences of China,2006,13(1):1-7]更多还原