Desiccation resistance and water balance in southern African keratin beetles (Coleoptera, Trogidae): the influence of body size and habitat
Desiccation resistance and water balance in southern African keratin beetles (Coleoptera, Trogidae): the influence of body size and habitat
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南部非洲角甲虫（鞘翅目、Trogidae）的抗干燥性和水平衡：体型和栖息地的影响
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发表时间：
1998
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影响因子：
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通讯作者：
C. Scholtz
中科院分区：
文献类型：
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作者：
M. Lagadec;S. Chown;C. Scholtz
摘要研究了7种不同大小、不同生境的刺蛾成虫的抗脱水能力和水分平衡。这些物种的身体含水量（51-58%的新鲜质量）和27 °C时的脱水速率（0.00026-0.00093 g h−1）与干旱栖息地中无关的相似大小的甲虫非常相似。角蛋白甲虫显着不同，从许多其他成年鞘翅目凭借其非常高的血淋巴渗透压和无法调节血淋巴渗透压，并分解代谢脂质的水生产，在干燥。与大多数其他昆虫一样，干旱地区的Trogid物种比中温带地区的Trogids具有更低的失水率和更长的生存时间。这是由于水分流失率较低，以及来自较干旱地区的物种体型较大。由于绝对身体含水量在大甲虫比小的，更大的身体尺寸赋予更高的抗干燥性非常大的卡拉哈里沙漠物种。这表明，在干旱地区的这种昆虫中，可能存在对大体型的强烈选择。大多数生态学和生态生理学研究的地理变异的身体大小，物种的身体大小分布，集中在温度和代谢率作为解释变量。这项研究表明，还应注意抗干燥性。
Abstract Desiccation resistance and water balance were examined in the adults of seven trogid species, which differed both in body size and in the habitats from which they were collected. Body water contents (51–58% fresh mass) and desiccation rates at 27 °C (0.00026–0.00093 g h−1) in these species were very similar to those of unrelated, similar-sized beetles from arid habitats. The keratin beetles differed markedly from many other adult Coleoptera by virtue of their very high haemolymph osmolality and inability to regulate haemolymph osmolality, and to catabolise lipids for water production, during desiccation. Like most other insects, the xeric trogid species had lower rates of water loss and longer survival times than trogids from mesic areas. This was due both to lower rates of water loss and to the larger body size of species from the more arid areas. Because absolute body water content was higher in large beetles than in small ones, larger body size conferred higher desiccation resistance on the very large Kalahari desert species. This suggests that there may be strong selection for large body size in such insects from arid areas. Most ecological and ecophysiological investigations of geographical variation in body size, and the species-body size distribution, have focused on temperature and metabolic rate as explanatory variables. This study suggests that attention should also be given to desiccation resistance.