Orestias ascotanensis Parenti is a critically endangered endemic species of the Chilean high Andean systems, found only in the springs of the Ascotán saltpan. Considering the importance of reproduction and early life history stages in population persistence in fishes, understanding these is essential for successful conservation efforts. We studied the larval development of O. ascotanensis under controlled temperature and photoperiod conditions. A total of 50 O. ascotanensis specimens were captured during 2014 and 2015 and moved to the laboratory to be kept under controlled conditions and diet. Females were subjected to hormone therapy using Ovaprim® to induce oviposition, which was followed by artificial fertilization under dry conditions. Water temperature was maintained at 20 °C (± 1 °C), conductivity values oscillated in the interval of 2800–3600 µS/cm³, and the photoperiod was established as 16:8 (light hours:dark hours). The larvae hatched within 14 to 18 days. Three larval stages were established: (i) flexion larva with yolk sac, (ii) flexion larva, and (iii) post-flexion larva. The newly hatched larvae were highly prepared for the free-living stage and they absorbed the yolk sac in 5–7 days. The intense pigmentation of O. ascotanensis eggs and larvae and the high degree of development at hatching may represent adaptations to extreme conditions, such as high levels of solar radiation and significant changes in daytime temperatures. A range of anthropogenic activities have caused the contraction and degradation of the habitat of O. ascotanensis, producing serious concern regarding the conservation status of the species.

Orestias ascotanensis Parenti 是智利高安第斯山脉系统的一种极度濒危的特有物种，仅在阿斯科坦盐田的泉水中发现。考虑到繁殖和早期生活史阶段在鱼类种群持久性中的重要性，了解这些对于成功的保护工作至关重要。我们研究了O的幼虫发育。ascotanensis在受控温度和光周期条件下。总共50 ö。亚斯科坦样本在 2014 年和 2015 年期间被捕获并转移到实验室，以保持在受控条件和饮食下。使用 Ovaprim® 对雌性进行激素治疗以诱导产卵，然后在干燥条件下进行人工受精。水温保持在 20 °C (± 1 °C)，电导率值在 2800–3600 µS/cm ³的区间内波动，光周期设定为 16:8（光照时间：黑暗时间）。幼虫在 14 至 18 天内孵化。建立了三个幼虫阶段：（i）具有卵黄囊的屈曲幼虫，（ii）屈曲幼虫，和（iii）屈曲后幼虫。新孵化的幼虫为自由生活阶段做好了充分的准备，它们在 5-7 天内吸收了卵黄囊。O的强烈色素沉着。一种scotanensis卵和幼虫以及孵化时的高度发育可能代表了对极端条件的适应，例如高水平的太阳辐射和白天温度的显着变化。一系列人为活动导致O栖息地的收缩和退化。ascotanensis，引起对该物种保护状况的严重关注。