Abrunhosa Fernando A, Simith Darlan J B, Monteiro Joely R C, Souza Junior Antonio N de, Oliva Pedro A C
Laboratório de Carcinologia, Instituto de Estudos Costeiros, Universidade Federal do Pará, Bragança, PA, Brasil.
An Acad Bras Cienc. 2011 Dec;83(4):1269-78. doi: 10.1590/s0001-37652011005000045. Epub 2011 Oct 21.
Feeding is an important factor for the successful rearing of larvae of the crab species. Further information on the morphological features of the foregut may to reveal larval feeding behaviour and or/whether there is a lecithotrophy in some or even in all stages of the larval cycle. In the present study, the structural development of the foregut and their digestive functions were examined in larvae of two brachyurans, Uca vocator and Panopeus occidentalis, reared in the laboratory. During larval development, the foreguts of the larvae in the first and last zoeal stages and in the megalopa stage were microscopically examined, described and illustrated. The zoeal foreguts of both species were well developed, showing specialization with a functional cardiopyloric valve and a filter press. The megalopa stage had a complex and specialized gastric mill similar to that found in adult crabs with the appearance of rigidly calcified structures. These results support the hypothesis that the feeding behaviour of each larval stage is directly related to the morphological structure of the foregut. Such facts strongly indicate that all larval stages of both U. vocator and P. occidentalis need an external food source before completing the larval development in a planktonic environment.
摄食是蟹类幼体成功培育的一个重要因素。关于前肠形态特征的更多信息可能有助于揭示幼体的摄食行为，以及在幼体发育周期的某些阶段甚至所有阶段是否存在卵黄营养。在本研究中，对实验室饲养的两种短尾类动物——招潮蟹（Uca vocator）和西方太平蟹（Panopeus occidentalis）的幼体前肠的结构发育及其消化功能进行了研究。在幼体发育过程中，对第一期和最后一期溞状幼体以及大眼幼体阶段的幼体前肠进行了显微镜检查、描述和绘图。两种溞状幼体的前肠都发育良好，具有功能性的贲门幽门瓣和滤器。大眼幼体阶段有一个复杂且特化的胃磨，类似于成年蟹的胃磨，出现了坚硬钙化的结构。这些结果支持了这样一种假设，即每个幼体阶段 的摄食行为都与前肠的形态结构直接相关。这些事实有力地表明，在浮游环境中完成幼体发育之前，招潮蟹和西方太平蟹的所有幼体阶段都需要外部食物来源。
