Roundup is the most popular glyphosate-based herbicide (GBH) worldwide. These formulations kill a wide range of plants. Despite that, non-target species can be jeopardized by GBH, such as the annual fish Austrolebias nigrofasciatus. This species occurs in wetlands that dries annually. key-adaptations permit them to live in such harsh habitats, e.i. elevated fertility, drought-tolerant diapausing embryos and elevated thermal tolerance. We aimed to evaluate acute (96 h) effects of Roundup exposure (0.36 or 3.62 mg a.e./L) in reproduction, diapause pattern and embryonic upper thermal tolerance (EUTT) of A. nigrofasciatus. For such, we evaluated the number and diameter of embryos produced by exposed fish. Also, recently fertilized embryos were exposed and its diapause pattern was evaluated. Following 15 post exposure days (PED), we evaluated the number of somite pairs and following 30, 35 and 40 PED we evaluated the proportion of pigmented embryos (PPE). Finally, the critical thermal maximum (CTMax) of exposed embryos was assessed. Results demonstrated that couples exposed to 0.36 mg a.e./L Roundup produced less but larger embryos. Similarly, embryos exposed to 3.62 mg a.e./L Roundup had a reduced PPE following 30 PED. Finally, embryos exposed to 0.32 mg a.e./L Roundup had a CTMax reduction of 2.6 ^oC and were more sensitive to minor increases in heating rates. These results indicate that Roundup have negative outcomes in fish reproduction, embryonic development and EUTT. This information is of particular interest to the conservation of annual fish, considering that those are key-adaptations that permit these animals to survive the harsh impositions of ephemeral wetlands.

农达是全球最受欢迎的草甘膦除草剂 (GBH)。这些制剂会杀死多种植物。尽管如此，非目标物种仍可能受到 GBH 的危害，例如一年生鱼类Austrolebias nigrofasciatus 。该物种出现在每年干燥的湿地中。关键的适应能力使它们能够生活在如此恶劣的栖息地， ei 。提高生育力、耐旱滞育胚胎和提高耐热性。我们的目的是评估农达暴露（0.36 或 3.62 mg ae/L）对黑带螟繁殖、滞育模式和胚胎耐热性上限（EUTT）的急性（96 小时）影响。为此，我们评估了暴露的鱼产生的胚胎的数量和直径。此外，还暴露了最近受精的胚胎并评估了其滞育模式。暴露后 15 天 (PED) 后，我们评估了体节对的数量，并在 30、35 和 40 PED 后评估了色素胚胎 (PPE) 的比例。最后，评估暴露胚胎的临界热最大值（CTMax）。结果表明，暴露于 0.36 毫克 ae/L 农达的夫妇产生的胚胎较少但较大。同样，暴露于 3.62 mg ae/L Roundup 的胚胎在 30 PED 后 PPE 降低。最后，暴露于 0.32 mg ae/L Roundup 的胚胎 CTMax 降低了 2.6 ^o C，并且对升温速率的轻微增加更加敏感。这些结果表明农达对鱼类繁殖、胚胎发育和 EUTT 具有负面影响。这些信息对于一年生鱼类的保护特别重要，因为这些是使这些动物能够在短暂湿地的严酷环境中生存下来的关键适应性。