五条鰤早期生长发育特征及胚胎发育的温度适应特性

The early growth and development characteristics of Seriola quinqueradiata and the temperature adaptation of embryonic development

中文关键词: 五条鰤  胚胎发育  胚后发育  形态特征  生长特征  温度适应

英文关键词: Seriola quinqueradiata  Embryonic development  Postembryonic development  Morphological characterisitcs  Growth performance  Temperature adaption

中文摘要:

      本研究采用显微摄像与形态度量的方法，首次系统观察和描述了五条鰤(Seriola quinqueradiata)胚胎和仔稚幼鱼阶段生长发育的形态与数量特征。结果显示，五条鰤成熟卵子为透明的圆球形浮性卵，卵径长为1.26~1.36 mm，单油球。在水温(22.0±0.5)℃、盐度30、pH 7.6~8.0的条件下，历时35 h 15 min孵化出膜。胚胎发育过程可分为卵裂前期、卵裂期、囊胚期、原肠期、神经胚期、器官发生期、肌肉效应期和脱膜孵化期8个时期。初孵仔鱼全长为(4.03±0.27) mm，卵黄囊呈长椭圆形，长度约为全长的3/8。3 DAH(day after hetching, DAH)仔鱼全长为(16.23±1.61) mm，开口，转入混合营养期，开口饵料为轮虫(Brachionus plicatilis)。6 DAH仔鱼全长为(4.93±0.17) mm，卵黄囊消耗殆尽，鳔开始充气。10 DAH仔鱼全长为(5.21±0.23) mm，油球消耗完毕，完全进入外源性营养阶段。15 DAH仔鱼全长为(6.24±0.66) mm，脊椎末端开始弯曲，至25 DAH时，稚鱼全长为(10.25±1.35) mm，弯曲过程完成，开始摄食卤虫无节幼体(Artemia salina)。30 DAH稚鱼全长为(16.23±1.61) mm，开始进行配合饲料转化；40 DAH稚鱼全长为(28.07±2.32) mm，苗种摄食配合饲料良好。65 DAH幼鱼全长为(81.49±5.11) mm，体态与成体相似。研究表明，五条鰤胚胎孵化的适宜温度范围为22℃~24℃。研究结果可为构建稳定的五条鰤苗种培育技术提供依据，保障深远海养殖优质种苗生产与供给。

英文摘要:

      Yellowtail amberjack, Seriola quinqueradiata, is a globally distributed, economically important, marine pelagic fish species belonging to the same genus as S. aureovittata and S. dumerili. It is a popular table fish worldwide because of its flavorsome flesh and high nutritional value. Recently, we made a breakthrough in triggering the natural spawning of S. quinqueradiata by manipulating photothermal regimes in China, and produced over 7700 juveniles with an average total length (TL) of 147 mm in an indoor tank culture system. Meanwhile, the morphological and quantitative characteristics and the growth and development of S. quinqueradiata during the early life history stages were observed and described for the first time. The mature eggs of S. quinqueradiata are transparent, spherical, and buoyant, with a single oil globe with a diameter of approximately 1.26~1.36 mm. The embryos hatched out at approximately 37 h 40 min post hatching at a water temperature of (22.0±0.5)℃. The embryonic development process can be divided into eight stages: pre-cleavage, cleavage, blastula, gastrula, neurula, organogenesis, muscle effect, and hatching. The morphology of embryonic development has been described previously. The TL of the newly hatched larvae was (4.03±0.27) mm with an oval yolk sac, which accounted for 3/8 of the TL. The TL of larvae 3 days after hatching (DAH) was (16.23±1.61) mm, and the mouth opened and larvae entered the mixed nutrition period. The first food was a rotifer. The TL of larvae at 6 DAH was (4.93±0.17) mm; here, the yolk sac was exhausted and the swim bladder started to inflate. The TL of larvae at 10 DAH was (5.21±0.23) mm, and the larvae entered the exogenous nutrition stage. The TL of larvae at 15 DAH was (6.24±0.66) mm, and the end of the spine began to bend. The TL of larvae at 25 DAH was (10.25±1.35) mm, and the spine bending process was completed; thereafter, the larvae began to feed on Artemia nauplii. The TL of juveniles at 30 DAH was (16.23±1.61) mm, which is when commercial feed conversion started, and the juveniles began to feed well on the commercial diet at 40 DAH when the TL reached (28.07±2.32) mm. The TL of juveniles at 65 DAH was (81.49±5.11) mm, which was when the juvenile morphology was similar to the adults. Furthermore, the suitable temperature for embryonic development was determined to be 22℃~24℃. The results provide technical support regarding artificial breeding and seedling production technology of S. quinqueradiata that could boost the development of the S. quinqueradiata farming industry in China.