CAJ | 학술논문

利用光学显微技术和透射电镜技术,观察和研究了出膜后1-35日龄黄颡鱼(Pelteobagrus fulvidraco)仔稚鱼的胃肠发育.水温为23-25℃时,2日龄仔稚鱼的消化道分化出口咽腔、食道、胃、肠;3日龄肠道分化为前肠、中肠、后肠.3日龄黄颡鱼开口摄食时其胃贲门部黏膜层下出现胃腺,为已有鱼类研究报道中胃腺最早出现的日龄.超微结构显示3日龄胃腺细胞中可见胃蛋白酶原颗粒和丰富的管泡系统,为典型的泌酸胃酶细胞;随日龄增加,胃蛋白酶原颗粒越来越丰富而管泡系统越来越不明显.3日龄时前肠吸收细胞胞质中可见脂肪泡,后肠吸收细胞胞质中可见蛋白质胞饮体.直到25日龄后肠吸收细胞胞质中尚可见蛋白质胞饮体.以七结果表明黄颡鱼在3日龄开口摄食时消化道具备细胞外消化功能,但此功能不完善,期间继续通过胞饮作用等细胞内消化来弥补胞外消化的不足,直到25-30日龄后细胞外消化功能发育完善.采用符合其生理机能发育过程的投喂管理策略可以有效提高大规格苗种培育的成活率.
이용광학현미기술화투사전경기술,관찰화연구료출막후1-35일령황상어(Pelteobagrus fulvidraco)자치어적위장발육.수온위23-25℃시,2일령자치어적소화도분화출구인강、식도、위、장;3일령장도분화위전장、중장、후장.3일령황상어개구섭식시기위분문부점막층하출현위선,위이유어류연구보도중위선최조출현적일령.초미결구현시3일령위선세포중가견위단백매원과립화봉부적관포계통,위전형적비산위매세포;수일령증가,위단백매원과립월래월봉부이관포계통월래월불명현.3일령시전장흡수세포포질중가견지방포,후장흡수세포포질중가견단백질포음체.직도25일령후장흡수세포포질중상가견단백질포음체.이칠결과표명황상어재3일령개구섭식시소화도구비세포외소화공능,단차공능불완선,기간계속통과포음작용등세포내소화래미보포외소화적불족,직도25-30일령후세포외소화공능발육완선.채용부합기생리궤능발육과정적투위관리책략가이유효제고대규격묘충배육적성활솔.
Yellow catfish (Pelteobagrus fulvidraco) is an important commercial freshwater species in China. Due to its high market value, the culture of this species has increased rapidly in recent years. However, larvae rearing became a major bottleneck because of its high mortality. In order to enhance the success of larvae rearing of P. fulvidraco, we need to know the ontogeny of its digestive system thoroughly. The purpose of this study was to understand the morphological structure and the ultrastructure of digestive tract during the ontogeny of P. fulvidraco. We hope that this information would provide fundamental knowledge for larvae rearing management for this species. The histological and ultrastructural characteristic studies of the stomach and intestine of yellow catfish were carried out from hatching ( Od after hatching ( DAH ) ) until 35 DAH. Larvae were hatched from artificially spawned broodstock and maintained in the laboratory ( water temperature was 23 -25℃). They were fed with zooplankton from 3 to 17 DAH, adding zoobenthos from 10 DAH, and only zoobenthos from 18 to 35 DAH. Development of the digestive tract in yellow catfish followed the general pattern described for other species. At hatching, it consisted of an undifferentiated straight tube laying over the yolk sac. The digestive tract was differentiated into buccopharynx, esophagus, initial stomach, and intestine by 2 DAH. The intestine became differentiated into anterior and posterior regions separated by a valve at 3 DAH. The gastric gland in cardiac stomach appeared at 3 DAH, the same time at the first feeding. In ultrastructure, oxynticopeptic cell contained pepsinogenic granules and abundant tubu-lovesicular systems at 3 DAH. The abundant visible tubulovesicular systems suggested that oxynticopeptic cell was still in rest phase with little hydrogen chloride ( HCl) secreted at the first appearance time. As larvae grew, more pepsinogenic granules but less tubulovesicular systems were found in oxynticopeptic cell. There were abundant pepsinogenic granules but little tubulovesicular systems in gastric gland cell at 25 DAH. The epithelial absorptive cell of the anterior and posterior intestinal segment showed electron-opaque lipid droplets and heavy pinocytosis at 3 DAH. Heavy pinocytosis was observed in the posterior intestine between 3 and 25 DAH. The results of this study suggested that the development of digestive tract of yellow catfish larva was functional rapidly, but incomplete. Pinocytotic absorption and intracellular digestion of proteins can compensate for this incomplete extracellular digestion. It is suggested feeding management strategy in line with the physiological function development process in order to effectively increase the survival rate of larva and juvenile of yellow catfish.