Hybrid Malaysian mahseer is a crossbreed between the male Malaysian mahseer, and female silver barb, through induced breeding. The study was carried out to observe the morpho-histological development of the F1 hybrid Malaysian mahseer larvae for the entire duration of its larval stage. Newly hatched larvae were reared in three 120 L aquaria at a stocking density of 5 larvae per liter. Larval development was observed daily from 1 to 9 DAH (day after hatching) and at 2-day intervals until 25 DAH by means of light and scanning electron microscopy (SEM), and histology. Newly hatched larvae had tiny body with closed mouth and simple gut formation. The hybrid larvae commenced exogenous feeding by 3 DAH using the taste buds and neuromasts to detect the presence of foods. Larval eyes were underdeveloped in early stage. They became fully functional as early as 9 DAH with larval TL and BW of 8.36 ± 0.24 mm and 4.3 ± 0.14 mg, respectively. By 7 DAH the stomach and intestinal tract were completely developed while complete tissue layers (mucosa, submucosa, muscularis and serosa) were visible in the larval gut by 18–21 DAH indicating the end of the larval stage. The post larval stage of the hybrid Malaysian mahseer was short and completed by 21–25 DAH when the scales fully covered its body. The rapid completion of larval stages and morphological features took after the maternal brood-fish, but with larger scales. These positive attributes in larval development could be of interest to the aquaculture industry.

中文翻译：

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马来西亚新杂交马赫西鱼（Barbonymus gonionotus ♀ × Tor tambroides ♂）的幼虫发育


杂交马来西亚鲅鱼是雄性马来西亚鲅鱼和雌性银鲃鱼通过诱导繁殖而产生的杂交品种。该研究的目的是观察 F1 代杂交马来西亚马赫鱼幼虫在整个幼虫阶段的形态组织学发育。将刚孵化的幼虫饲养在三个120L水族箱中，饲养密度为每升5只幼虫。从 1 至 9 DAH（孵化后一天）每天观察幼虫发育，每隔 2 天观察一次，直到 25 DAH 通过光学和扫描电子显微镜 (SEM) 以及组织学观察。刚孵化的幼虫身体很小，嘴巴闭合，肠道结构简单。杂交幼虫在 3 DAH 时开始外源进食，使用味蕾和神经丘来检测食物的存在。幼虫早期眼睛发育不全。它们早在 9 DAH 时就已完全发挥功能，幼虫 TL 和 BW 分别为 8.36±0.24mm 和 4.3±0.14mg。到 7 DAH 时，胃和肠道已完全发育，而到 18-21 DAH 时，幼虫肠道中可见完整的组织层（粘膜、粘膜下层、肌层和浆膜），表明幼虫阶段结束。杂交马来西亚鲢鱼的后幼体阶段很短，在 21-25 DAH 时完成，此时鳞片完全覆盖其身体。幼鱼阶段的快速完成和形态特征与母鱼相似，但规模更大。幼体发育的这些积极特性可能会引起水产养殖业的兴趣。