Diapause in copepods (Crustacea) from ephemeral habitats with different hydroperiods in Everglades National Park (Florida, U.S.A.)
Diapause in copepods (Crustacea) from ephemeral habitats with different hydroperiods in Everglades National Park (Florida, U.S.A.)
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大沼泽国家公园（美国佛罗里达州）不同水文期短暂栖息地的桡足类（甲壳类）滞育
作者：
M. Bruno;W. Loftus;J. Reid;S. Perry
大沼泽地的水资源管理措施严重影响了自然系统，特别是减少了该地区大部分地区的水文周期。在1999年的旱季，我们调查了水文周期对季节性湿地的大沼泽地国家公园，佛罗里达，美国的栖息地的特点是每年的旱季，从12月到6月的淡水桡足类群落的物种组成和休眠模式的影响。我们在两个地点进行了采样：落基山脉林间空地地区的长松关键地区（短水文周期，约。4-5月），和西部泰勒斯劳（中期水文周期，约. 8-10月）。这两个地区都经历了自然水文周期的减少和干旱频率的增加。我们每周收集浮游生物样本从岩石林间空地解决方案孔，以评估潜在的桡足类物种池。为了记录能够通过休息来生存的类群，我们进行了三次浸泡试验，在实验室水族箱中，我们进行了再水化，从所有站的溶液孔和表层土壤的沉积物补丁。只有一个子集的南极物种收集出现在干燥的沉积物。剑水蚤以红剑水蚤和波氏拟剑水蚤占优势。这是首次记录到桃实蝇滞育现象。不同水文周期土壤斑块的物种分布表明，更多滞育物种发生在干燥时间较短的网站。M.红腹叶蜂和桃实蝇以产卵为主，表现出一种罕见的休眠策略。在我们的试验中，近环剑水蚤出现在干燥的沉积物中，以前没有报道过滞育。我们收集了六个佛罗里达的新记录：Diacyclops nearcticus，Megacyclops latipes，Orthocyclops modestus，Elaphoidella marjoryae，Bryocamptus sp.和Bryocamptuscf。纽约的。波氏拟剑水蚤、暗色大剑水蚤和佛罗里达北极水蚤是大沼泽地国家公园的新记录。显然，滞育是桡足类在短水周期湿地中持续生存的重要策略。干旱期的持续时间似乎与滞育后出现的物种数量成反比。
Water management practices in the Everglades have severely stressed the natural system, particularly by reducing the hydroperiods of much of the region. During the dry season of 1999, we investigated the influence of hydroperiod on the species composition and dormancy patterns of freshwater copepod communities in seasonal wetlands of Everglades National Park, Florida, U.S.A. The habitats were characterized by an annual dry season, from December through June. We sampled at two locations: the Long Pine Key area of the Rocky Glades region (short hydroperiod, ca. 4–5 months), and western Taylor Slough (intermediate hydroperiod, ca. 8–10 months). Both areas have experienced a reduction in natural hydroperiods and an increase in the frequency of dry-down. We collected weekly plankton samples from Rocky Glades solution holes to assess the potential species pool of copepods. To document the taxa capable of surviving dry-down by resting, we performed three immersion trials in which we rehydrated, in laboratory aquaria, sediment patches from solution holes and surface soils from all stations. Only a subset of the planktonic species collected emerged from the dried sediments. The cyclopoids Microcyclops rubellus and Paracyclops poppei were dominant. This is the first record of diapause for P. poppei. Species distributions from the different hydroperiod soil patches indicated that more diapausing species occurred at the sites that dried for shorter periods. Emerging individuals of M. rubellus and P. poppei were mainly ovigerous females, demonstrating a resting strategy seldom before recorded. The cyclopoid Diacyclops nearcticushad not been previously reported to diapause, but they emerged from the dried sediments in our trials. Our collections included six new records for Florida: Diacyclops nearcticus, Megacyclops latipes, Orthocyclops modestus, Elaphoidella marjoryae, Bryocamptus sp. and Bryocamptuscf. newyorkensis. Paracyclops poppei, Macrocyclops fuscus and Arctodiaptomus floridanus are new records for Everglades National Park. Clearly, diapause is an important strategy for the persistence of copepods in short-hydroperiod wetlands. The duration of the dry period appears to be inversely related to the number of species that emerge from diapause.