绿鳍马面鲀外部器官的早期发育

Early developmental characteristics of external apparatus of bluefin leatherjacket Thamnaconus modestus

中文关键词: 绿鳍马面鲀  仔稚鱼  器官发育

英文关键词: Thamnaconus modestus  External apparatus  Development

中文摘要:

      本研究分别描述了绿鳍马面鲀人工繁育过程中11个器官的发育特征。口：2～3 dph开口后持续生长，在24～28 dph出现短时期停滞，建议此时保证小型饵料供给。眼：1 dph色素出现，3 dph脉络膜形成、瞳孔黑色，4 dph巩膜形成，14 dph眼眶出现，40 dph与成鱼基本一致。第一背鳍棘：3 dph原基出现，7～8 dph鳍棘初成，10 dph凸出体外，14dph基本形成，60 dph与成鱼基本一致。腰带骨与腹鳍棘：5 dph腰带骨出现，60 dph腰带骨与成鱼一致，5～7 dph腹鳍棘生长迅速，10 dph逐渐萎缩，至30 dph全部脱落。胸鳍：15 dph胸鳍膜加厚，鳍条形成，30 dph基本发育完善。背、臀鳍：14 dph出现支鳍骨和鳍条，24dph鳍条基本发育完全，60 dph与成鱼基本一致。尾鳍：0～14 dph尾椎平直，16 dph尾尖下方出现鳍条原基，16～24 dph尾尖上曲，鳍条完善并分节，50 dph尾鳍圆形。皮肤：8 dph表皮加厚，头部首先出现致密表皮，40 dph全身被鳞；120 dph成为柔韧结实的革状表皮。内脏团：2 dph卵黄囊吸收完毕，肛门形成，出现第一个肠袢；3dph油球消失，仔鱼摄食；8～12 dph肝、肾和鳔的原基出现，16dph肾脏、肝脏和鳔形成，18dph脾脏形成。连续测定了总高、肛门前长、水平眼径和下颌侧长的生长并绘制了生长曲线。

英文摘要:

      This study described the developmental characteristics of external apparatus during early life stages of bluefin leatherjacket, Thamnaconus modestus. The developmental morphological characteristics of 11 external apparatus were recorded and described in detail. 1) Mouth: opened at 2-3 dph(days post hatching), then grew continuously except at the stagnation stage (24-28 dph). 2) Eyes: pigment appeared at 1 dph, choroids formed and the pupil was black at 3 dph, sclera formed at 4 dph, rim of the eye appeared at 14 dph, and the eye form was same with adults at 40 dph basically. 3) First dorsal fin spine: anlage appeared at 3 dph, fin spine formed initially at 7-8 dph, protruded out of body at 10 dph, development finished roughly at 14 dph, and the shape was the same with adult at 60 dph basically. 4) Girdles and pelvic fin spine: Girdles appeared at 5 dph, pelvic fin spine grew fast at 5-7 dph, and shunk from 10 dph, all pelvic fin spine off at 30 dph. The shape of girdles was the same with adult at 60 dph. 5) Pectoral fin: fin membrane thickened and the fin ray formed at 15 dph, developed completely at 30 dph. 6) Dorsal fin and anal fin: fin suspensorium and fin ray appeared at 14 dph, fin ray developed completely at 24 dph, and the shape at 60 dph was the same with adult’s. 7) Caudal peduncle: caudal vertebra was straight until 14dph, some fin ray anlage appeared under the tail end of notochord at 16 dph. The tail end of notochord up-curved, fin ray developed completely and sub-section at 16-24 dph. Caudal fin turned into rotundity at 50 dph. 8) Scales and skin: epidermis thickened at 8dph, the compact epidermis appeared first at head, full body covered by scales at 40dph, turned into withy leathery epidermis. 9) Abdomen and splanchnic zone: yolk-sac was absorbed, anus and the first intestinal loop formed at 2 dph, oil ball disappeared and the fish larvae fed on the oyster larvae. The anlages of liver, kidney and swim bladder appeared at 8-12 dph, and the three organs formed at 16 dph. Spleen formed at 18 dph. The growth curve of total height, pre-anus length, eye length and side length of lower jaw during 0-75 dph were also described in the present study.