Summary This study describes the embryonic development of Moenkhausia oligolepis in laboratory conditions. After fertilization, the embryos were collected every 10 min up to 2 h, then every 20 min up to 4 h, and afterwards every 30 min until hatching. The fertilized eggs of M. oligolepis measured approximately 0.85 ± 0.5 mm and had an adhesive surface. Embryonic development lasted 14 h at 25ºC through the zygote, cleavage, blastula, gastrula, neurula, and segmentation phases. Hatching occurred in embryos around the 30-somites stage. The present results contribute only the second description of embryonic development to a species from the Moenkhausia genus, being also the first for this species. Such data are of paramount importance considering the current conflicting state of this genus phylogenetic classification and may help taxonomic studies. Understanding the biology of a species that is easily managed in laboratory conditions and has an ornamental appeal may assist studies in its reproduction to both supply the aquarium market and help the species conservation in nature. Moreover, these data enable the use of M. oligolepis as a model species in biotechnological applications, such as the germ cell transplantation approach.

中文翻译：

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Fire-eye-tetra Moenkhausia oligolepis (Characiformes: Characidae) 的胚胎发育

总结 本研究描述了鳐鱼在实验室条件下。受精后，每 10 分钟收集一次胚胎直至 2 小时，然后每 20 分钟收集一次，直至 4 小时，然后每 30 分钟收集一次直至孵化。受精卵的M. oligolepis测量大约 0.85 ± 0.5 mm 并具有粘性表面。胚胎发育在 25ºC 下持续 14 小时，经历受精卵、卵裂、囊胚、原肠胚、神经胚和分割阶段。孵化发生在 30 体节左右的胚胎中。目前的结果仅对胚胎发育的第二个描述做出了贡献。蒙克豪斯属，也是该物种的第一个。考虑到该属系统发育分类的当前冲突状态，这些数据至关重要，并且可能有助于分类学研究。了解在实验室条件下易于管理并具有观赏吸引力的物种的生物学可能有助于研究其繁殖，以供应水族市场并帮助自然界中的物种保护。此外，这些数据使使用M. oligolepis作为生物技术应用中的模型物种，例如生殖细胞移植方法。