大口黑鲈开口摄食与转食人工配合饲料期消化系统发育特征  

Early Developmental Characteristics of Digestive System of Micropterus salmoides Larvae During the First Feeding and Artificial Formula Feed Adaptation

作　　者：李武辉 孙成飞[1] 董浚键[1] 杨超 胡婕 田园园[1] 叶星[1] LI Wuhui;SUN Chengfei;DONG Junjian;YANG Chao;HU Jie;TIAN Yuanyuan;YE Xing(Pearl River Fisheries Institute,Chinese Academy of Fishery Sciences,Key Laboratory of Tropical and Subtropical Fisheries Resource Application and Cultivation,Ministry of Agriculture and Rural Affairs,Key Laboratory of Aquatic Animal Immune Technology of Guangdong Province,Guangzhou,Guangdong 510380,China;State Key Laboratory of Developmental Biology of Freshwater Fish,Hunan Normal University,Changsha,Hunan 410081,China)

机构地区：[1]中国水产科学研究院珠江水产研究所,农业农村部热带亚热带水产资源利用与养殖重点实验室,广东省水产动物免疫技术重点实验室,广东广州510380 [2]湖南师范大学省部共建淡水鱼类发育生物学国家重点实验室,湖南长沙410081

出　　处：《渔业科学进展》2023年第1期80-89,共10页Progress in Fishery Sciences

基　　金：广东省重点领域研发计划项目(2021B0202020001);财政部和农业农村部:国家现代农业产业技术体系(CARS-46);2021年乡村振兴战略专项资金省级项目;中国水产科学研究院基本科研业务费(2020TD23);农业农村部热带亚热带水产资源利用与养殖重点实验室开放课题基金(2019A01)共同资助。

摘　　要：本研究利用组织切片和扫描电镜技术,观察和研究了2~30日龄大口黑鲈(Micropterus salmoides)仔鱼消化系统的发育过程及组织学变化。结果显示,在水温为(23±1)℃条件下,0~4日龄仔鱼消化道初步分化,为内源性营养期;4~6日龄仔鱼消化道逐渐分化形成食道、胃和肠,胃和肠黏膜褶形成,肝胰脏细胞团出现,仔鱼具备基本摄食能力,进入混合性营养期;10~16日仔鱼消化道和消化腺结构分明,胃、幽门盲囊、肠道紧密排列,肝脏和胰脏独立,进入外源性营养期,此阶段后可逐步转食人工配合饲料。20~30日仔鱼胃腺发达,胃和肠道出现次级黏膜褶,幽门盲囊黏膜褶显著增多、增长,肝脏逐渐出现脂肪积累区,胰脏可见酶原分泌颗粒,肝胰脏组织结构近似成鱼。扫描电镜显示,30日仔鱼胃部内表皮具有丰富的网状黏膜褶,胃小凹间分布着密集的分泌孔;幽门盲囊和肠道内表面结构相似,无固定形态的黏膜褶上布满黏液细胞和分泌孔。20日龄后仔鱼具备转食人工配合饲料的能力。此外,在仔鱼开口和转食人工配合饲料过程中,部分死亡个体的胃肠组织表现出腔体扩大或皱缩,内表皮无成型的黏膜褶或黏膜层脱落,胃和肠道组织损伤。本研究可为大口黑鲈仔鱼开口和转食人工配合饲料条件的优化提供组织学基础资料。Micropterus salmoides is an economically important cultured carnivorous fish in China. In recent years, owing to the development and wide application of artificial formula feed, M. salmoides production has rapidly increased and reached 470 000 tons in 2019. However, a low survival rate of M. salmoides larvae is observed during the first feeding and artificial formula feed adaptation.In this study, to better understand the artificial formula feed adaptation of M. salmoides larvae, the developmental characteristics of the digestive tract and digestive gland of the fish larvae from 2~30 dph were observed and described using histological sections and scanning electron microscopy(SEM).Moreover, the digestive tract(stomach and intestine) characteristics of certain dead larval fish during the first feeding and the transformation of artificial formula feed were investigated.For histological analysis, the larval fish(including stomach, intestine, pyloric cecum, liver, and pancreas tissues) were dehydrated with an alcohol gradient(70%, 80%, 90%, and 100%), embedded in paraffin, cut into 5 μm sections, and stained with standard hematoxylin and eosin.For SEM analysis, the stomach, pyloric cecum, and intestine of 30 dph larval fish were fixed in 2.5%glutaraldehyde solution for 12 h. Then, the tissues were fixed in 1% osmium solution for 2 h, dehydrated with gradient alcohol(70%~100%), soaked in tert-butyl alcohol for 2 h, dried with a lyophilizer, and plated with gold by ion sputtering. Finally, the images were captured using a HITACHIX-650 scanning electron microscope.At a water temperature of(23±1)°C, the larval yolk sac and oil drop gradually decreased at 0~4 dph,the digestive tract was initially differentiated, and heartbeat, blood circulation, mouth crack, esophagus,and anus were observed at 4 dph. Larval fish were in the endogenous nutrition period at this stage. In 4~6 dph larval fish, the esophagus, stomach, intestine, liver, and pancreas regions gradually formed, the digestive tube opened to the outside initially,

关 键 词：大口黑鲈 消化系统 组织学 扫描电镜 

分 类 号：S963[农业科学—水产养殖]