Centro de Aquicultura da Universidade Estadual Paulista (CAUNESP). Via de Acesso Professor Paulo Donato Castellane, S/N, CEP: 14884-900. Jaboticabal, São Paulo, Brazil.
Piscicultura Buriti. P.O. Box 198, CEP: 78450-000. Nova Mutum, Mato Grosso, Brazil.
Zygote. 2020 Jun;28(3):208-216. doi: 10.1017/S0967199420000015. Epub 2020 Feb 20.
In the present study, the morphological development of the Brycon amazonicus digestive tract is described to provide basic knowledge for nutritional studies and, therefore, increase the survival of this species during larviculture. Samples were collected from hatching up to 25 days of age, measured, processed and observed under a stereomicroscope and light microscopy. Newly hatched larvae presented their digestive tract as a straight tube, dorsal to the yolk sac, lined with a single layer of undifferentiated cells. At 24 h post-hatching (hPH), the buccopharyngeal cavity was open, but the posterior region of the digestive tube remained closed. At 25 hPH, the digestive tube was completely open and could be divided into buccopharyngeal cavity, oesophagus and intestine. At 35 hPH, the intestine presented a dilatation in the proximal region, which had the function of storing food. Differentiation of the stomach started at 83 hPH, and mucous cells were observed in the epithelium. These cells are important in the production of mucus, whose function is to protect the organ against acidity, although the gastric glands began developing only from 171 hPH, when three stomach regions were observed: cardiac, fundic and pyloric. The gastric glands were observed in the cardiac region, indicating that this organ already had digestive functionality. From 243 hPH, the absorption and assimilation of nutrients were already possible but, only from 412 hPH, the digestive tract was completely developed and functional.
本研究描述了亚马逊脂鲤消化道的形态发育，为营养研究提供了基础知识，从而增加了该物种在幼鱼养殖阶段的成活率。采集了孵化后 0 至 25 天的样本，进行测量、处理并在立体显微镜和光学显微镜下观察。刚孵化的仔鱼消化道呈直管状，位于卵黄囊背侧，由单层未分化细胞组成。孵化后 24 小时（hPH）时，口咽腔张开，但消化道后端仍闭合。孵化后 25 小时时，消化道完全张开，可分为口咽腔、食管和肠。孵化后 35 小时时，肠的近端出现扩张，具有储存食物的功能。胃的分化始于 83 hPH，上皮中观察到黏液细胞。这些细胞在产生黏液方面很重要，黏液的功能是保护器官免受酸性影响，尽管胃腺仅从 171 hPH 开始发育，此时观察到三个胃区：贲门、胃底和幽门。胃腺存在于贲门区，表明该器官已经具有消化功能。从 243 hPH 开始，就已经能够吸收和同化营养物质，但只有从 412 hPH 开始，消化道才完全发育并具有功能。
