高体革(鱼市)消化道发生的组织学观察

Histological studies on development of the digestive system of Scortum barcoo

利用形态学和连续组织切片技术,对出膜后1～30d的高体革(鱼刺)消化系统胚后发育的组织形态学进行了系统观察和研究。结果表明,培养水温在26.6～29.7℃条件下,高体革(鱼刺)初孵仔鱼消化管为一柱形盲管,管腔狭窄,口、肛门尚未与外界接通。出膜30h仔鱼,口开始张开,消化管相通。出膜2d仔鱼肠壁出现皱褶,肠瓣将肠道分为前肠和后肠,在显微镜下可见消化管蠕动。出膜3d仔鱼可以开口摄食,消化管上皮分化,食管中出现黏液细胞,肝脏和胰脏出现,鱼体由内源性营养转入混合营养阶段。混合营养阶段仔鱼消化道明显分为口咽腔、食道、胃、前肠、直肠等,消化腺肝脏和胰脏也已形成,各部分已经有初步结构和一定的消化吸收能力。随着仔鱼的发育,仔鱼消化系统各器官也趋于完善。出膜21d稚鱼的胃壁出现胃腺,标志着稚鱼期开始。

Histological changes of the digestive system and its associated glands were studied in jade perch, Scortum barcoo from the first day （first day post-hatch, dph） to 30 dph. Specimens for this study were hatched from artificially spawned broodstock and maintained in the indoor plastic tanks （ 26.6 - 29.7 ℃ ）. The newly hatched larvae had one big yolk sac, and their digestive tract was only a columniform diverticulum, without communication with outside. Digestive tract communication with outside in 30-hour- old larva and their mouth shut up. 2-day-old larvae＇ s gut started crumple and peristalsis. The intestinal had been divided into anterior intestine and posterior intestine by intestinal valve. 3-day-old larvae could be fed, the epithelial of digestive tract begun differentiation, mucous cells appeared in esophageal, pancreas and liver appeared. The nutrition of fish began transferred to the stage of mixed nutrition. In this stage, the digestive tract was differentiated into five portions： buccal-pharyngeal cavity, esophagus, stomach, anterior intestine and posterior intestine, liver and pancreas had also been formed; these organs already had initial structure and the capacity of digestion and absorption. Along with the development of larvae fish, digestive system tended to perfect. Gastric glands appeared in the stomach of 21-day-old juvenile, marking the beginning of juvenile.