| 摘要: |
| 圆斑星鲽成熟卵子透明、光滑、无油球，卵径1.75±0.08 mm(n=30)。在水温11±0.5 ℃、盐度31~32、DO≥5 mg/L条件下，受精卵经159 h脱膜孵出，胚胎发育下限温度为5.14 ℃，发育时间与温度呈负相关关系。初孵仔鱼体色透明，全长4.95±0.15 mm（n=30），7日龄，仔鱼体覆黑色素，口和肛门贯通，口裂0.32 mm时开始摄食轮虫；11日龄，卵黄囊耗尽，仔鱼由内源性营养转化为外源性营养方式，开始摄食卤虫无节幼体；17日龄，进入尾椎弯曲期，尾扇和下尾骨形成；28日龄，尾鳍色素沉积；33日龄，尾椎弯曲完成，仔鱼左眼开始向右侧翻转，进入变态期，尾鳍条增至18根；45日龄稚鱼体表色素带形成，背、腹鳍各覆4~5个棕黑色斑点；50日龄，变态完成，左眼完全翻转至右侧，开始营底栖生活；70日龄，幼鱼体被鳞片逐渐形成，各鳍条均发育至定数，体态和生活习性与成鱼无异。 |
| 关键词: 圆斑星鲽 胚胎发育 仔稚鱼 形态特征 |
| DOI： |
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| 基金项目:国家“863”计划项目（2006AA10A414；2010AA10A402）、国家鲆鲽类产业技术体系（nycytx-50）和公益性农业行业专项项目（nyhyzx07-046）共同资助 |
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| Morphological development and growth pattern of Verasper variegatus, Temminck et Schlegel in early life stages |
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| Abstract: |
| Morphological and quantitative characteristics of Verasper variegatus in early life stages including embryonic development, yolk sac larva, pre-flexion larva, post-flexion larva, and juveniles were recorded. The eggs are 1.75mm 0.08mm in diameter, without oil globule and spherical in shape when they are suspended in sea water. There is negative a relationship between the temperature and the hatching time, and the calculated lower threshold temperature for hatching of embryos is 5.14 ℃. The larvae hatched out 159h post fertilization at temperatures of 11±0.5 ℃, salinity of 31-32, and DO≥5mg/L. The newly hatched larvae is transparent and 4.95±0.15mm in total length. Larval development and growth completely depended on the energy from the yolk sac and oil globe till 7 DAH (days after hatching). Meantime, mouth and anus opened, larvae entered the mixed feeding stage. Larvae entered the complete exogenous feeding stage after the yolk was completely absorbed at 11DAH. The first feeding food was L type rotifers Brachionus plicatilis. Larvae began to feed rotifers at 7 DAH. At 11 DAH, larvae were fed nauplii of brine shrimp Artemia salina at densities of 0.5 1.5 ind./ml till 46 DAH. Weaning to commercial diet started at 31 DAH and larvae fed mainly commercial diet after 40 DAH. There is no swim bladder present all through the early life history. The flexion of notochord started at 17 DAH at a total length of 7.32 0.23 mm (n=30), and finished at 33DAH when the total length reached 11.2 0.33 mm (n=30). Meanwhile, metamorphosis began at 33 DAH and completed at 50 DAH with the left eye moved completely to the right side, and the juveniles entered the bottom life stage. At 70 DAH, lateral line formed and the juveniles entered the young stage with the total length up to 25.3 3.23 mm (n=30), with similar appearance as the adults. The dorsal fin, pectoral fin, pelvic fin, caudal fin, and anal fin reached their full numbers at 70DAH. There were 4-5 black spots on the dorsal and pectoral fins at 45DAH, which is same as the adults. |
| Key words: Verasper variegatus Embryonic development Larva and juveniles Morphological characteristics |
