Morrison C M, Miyake T, Wright J R
Department of Pathology, IWK-Grace Health Center, Dalhousie University, Faculty of Medicine, Halifax, Nova Scotia, Canada B3J 3G9.
J Morphol. 2001 Feb;247(2):172-95. doi: 10.1002/1097-4687(200102)247:2<172::AID-JMOR1011>3.0.CO;2-H.
The developmental stages of Oreochromis niloticus are similar to those described in other mouth-breeding tilapias except that, as in zebrafish, no cavity was found in the blastula. Variation in the rate of development of the embryo and larva of O. niloticus was found within a clutch of eggs as well as between clutches. Hatching glands are described for the first time in tilapias. They are widely distributed within the ectoderm covering the head, body, tail, and surface of the yolk sac near its attachment to the embryo. Timing of larval development is similar to that in other mouthbrooding tilapias, but is slower than that found in substrate-spawning tilapias. A pneumatic duct connects the swimbladder to the digestive tract and swimbladder inflation and initiation of feeding occurs at about the same time. The digestive tract of the larva 8 and 9 days after fertilization is similar to that found in the adult, except that there are no digestive glands. An endocrine pancreatic islet was first seen 76 h after fertilization. A prominent thymus gland is present at 100 h. Hematopoietic tissue develops in the vicinity of the pronephros during early larval development. A spleen develops later, 7 days after fertilization.
尼罗罗非鱼的发育阶段与其他口育罗非鱼所描述的相似，只是与斑马鱼一样，在囊胚期未发现腔。在一窝卵内以及不同窝卵之间，尼罗罗非鱼胚胎和幼体的发育速度存在差异。首次在罗非鱼中描述了孵化腺。它们广泛分布于覆盖头部、身体、尾部以及卵黄囊与胚胎附着处附近表面的外胚层内。幼体发育的时间与其他口育罗非鱼相似，但比基质产卵罗非鱼慢。一条鳔管将鳔与消化道相连，鳔充气和开始摄食大约同时发生。受精后8天和9天的幼体消化道与成体相似，只是没有消化腺。受精后76小时首次见到内分泌胰腺胰岛。受精后100小时出现一个明显的胸腺。造血组织在幼体早期发育过程中在前肾附近发育。脾脏在受精后7天稍后发育。
