【摘要】 利用采自赤水河下游的银鮈(Squalidus argentatus)鱼卵对其早期发育进行了观察和描述,并对仔鱼的耐饥饿能力进行了研究。银卵属中等大小的漂流性卵,具双层卵膜,外膜径(3.35±0.41)mm。胚胎发育分32个发育期,在水温24.6～25.5℃时历时40h。初孵仔鱼全长(3.84±0.36)mm,眼下有一个黑点,胸鳍原基已形成,经85d左右发育成幼鱼。仔鱼孵出后2～3d开口摄食,5日龄时初次摄食率即达100%。持续饥饿对银鮈仔鱼生长、发育、存活均有很大影响,饥饿仔鱼11～12d达不可逆点(PNR),饥饿至13日龄时,绝大部分仔鱼死亡。更多还原

【Abstract】 The eggs of Squalidus argentatus were collected in the lower reaches of the Chishui River from March to July,2007. Ontogenesis of S. argentatus was observed,and starvation tolerance of the larva was studied. The egg of S. argentatus belongs to middle-sized drifting egg,which had two layers of membrane,with the outer layer 3. 35 ± 0. 41 mm in diameter. Embryonic development was subdivided into 32 stages,which lasted for about 40 hours under the water temperature of 24. 6 to 25. 5℃ . The average total length of newly hatched larvae was 3. 8mm,with rudiment of pectoral fin and a macula under its eye. Before developing to a young fish, postembryonic development of the larva lasted for about 85 days. The larva began to feed on the second or the third day after hatching,and then the initial feeding rate reached the highest level of 100% on the 5th day. Effects of starvation on growth,development and survival were observed. The point of no return (PNR) was 11 to 12 days after hatching,and almost all larvae died before the 13th day.更多还原