The impact of climate variability on recruitment, life history, and physiology of sympatric pairs of ciscoes (Teleostei: Coregonus spp.) in lakes

最近，有人推测，全球变暖的趋势可能有利于春季产卵的一年级实力，而不是秋季产卵的鱼类。背后的机制被认为是一个不同的时间孵化的鱼和春季高峰的浮游动物作为食物的小鱼，和一个可变的招聘由于温度敏感的适应生命周期。在这里，我们比较孵化和早期招聘的同域对物种的ciscoes在一个深湖，其中一个物种产卵在秋季，另一个在春季的时间。在这个冰后期湖泊中，物种形成和分化发生在过去的10，000年中。这两个鱼种之间的生态、行为和生理差异（产卵时间除外）被认为很小。通过跟踪这两个物种早期生命阶段的生长、摄食、分布和生理表现，我们想测试春季产卵的物种是否确实能更好地适应预期的提前破冰和由于全球变暖而导致的更高的泉水温度。此外，通过检查沿岸的捕食性鱼类的胃内容物，估计这两个物种对食鱼性鱼类的捕食风险。今后，还应分析这两个物种和潜在杂种对寒冷和温暖温度的生理适应。

Recently, it has been speculated that global warming trends may favor year-class strengths of spring-spawning in opposition to autumn-spawning fish species. The mechanisms behind were assumed to be a differential timing of the hatching of fish and the spring peak of the zooplankton as food for the small fish, and a variable recruitment due to temperature-sensitive adaptations of the life cycle. Here, we compare the timing of hatch and early recruitment of a sympatric pair species of ciscoes in a deep lake whereby one species spawns in autumn, and the other in spring. In this postglacial lake, speciation and divergence have occurred during the last 10,000 years. The ecological, behavioural and physiological differences between both species (except for the spawning time) are assumed to be low. By following the growth, feeding, distribution and physiological performance of the early life stages of both species, we want to test whether the spring-spawning species is indeed better adapted to the anticipated earlier ice break and higher spring water temperatures due to global warming. Furthermore, the predation risk against piscivorous fish is estimated for both species by inspecting the stomach content of littoral predatory fish. In the future, the physiological adaptation of both species and potential hybrids to cold and warm temperatures shall be analysed in addition.