SummaryStudies on the larval development of fish are essential for conservation and improvements in cultivation techniques. Geophagus brasiliensis popularly known as Cará has potential as a fish of interest in ornamental aquaculture. Wild adults of G. brasiliensis were kept in an aquarium for spontaneous reproduction. Newly hatched larvae were transferred to 5-litre aquaria at 22, 26 and 30°C until total yolk sac resorption. Histological slides were used for biometric analysis and monitoring of larval ontogenesis at different temperatures. Histologically, from the first to the fourth days it was possible to identify myomeres, optic vesicle, yolk syncytial layer, brain, heart and differentiation of the eye layers. From the fourth to the seventh days, it was possible to identify mandibular and gill cartilages, swim bladder, liver, prismatic epithelium with striated border in intestine and renal epithelium. All biometric measurements increased over the days, except height and length of the yolk sac, which gradually decreased until the complete resorption of the yolk sac that occurred on the fifth day at a temperature of 30°C, the sixth day at 26°C and the seventh day at 22°C. Morphological events at 30°C such as the reabsorption of the yolk sac, the appearance of cartilage in the branchial arches and differentiation of the layers of the eyes occurred faster compared with the other temperatures tested. Opening of the mouth and digestive tract occurred at a similar time on the fourth day in all temperatures.

中文翻译：

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温度对巴西土鳖幼虫个体发育的影响 (Quoy & Gaimard, 1824) (Pisces: Cichlidae)

总结对鱼类幼体发育的研究对于保护和改进养殖技术至关重要。巴西土鳖俗称卡拉有潜力成为观赏水产养殖的鱼类。野生成虫G. brasiliensis被保存在水族箱中进行自然繁殖。将新孵化的幼虫转移到 22、26 和 30°C 的 5 升水族箱中，直至卵黄囊完全吸收。组织学载玻片用于生物特征分析和监测不同温度下的幼虫个体发育。组织学上，从第一天到第四天，可以识别肌球、视泡、卵黄合胞层、大脑、心脏和眼层的分化。从第四天到第七天，可以识别出下颌和鳃软骨、鱼鳔、肝脏、肠内有横纹边缘的棱柱状上皮和肾上皮。除了卵黄囊的高度和长度外，所有生物特征测量值都在增加，逐渐减少，直到在 30°C 的第五天、26°C 的第六天和 22°C 的第七天发生卵黄囊完全吸收。与其他测试温度相比，30°C 下的形态学事件（例如卵黄囊的重吸收、鳃弓中软骨的出现和眼睛各层的分化）发生得更快。在所有温度下，第四天张口和消化道的时间相似。