Combs C A, Alford N, Boynton A, Dvornak M, Henry R P
Biol Bull. 1992 Jun;182(3):416-423. doi: 10.2307/1542261.
Drinking behavior in Birgus latro and Gecarcoidea lalandii was videotaped under controlled laboratory conditions. B. latro displayed the drinking behavior typically observed in nature, spooning up water with the chelae (Lister, 1888; Gross, 1955). G. lalandii is documented for the first time displaying this same behavior; however it obtained water primarily through immersion. Under normal hydrated conditions (hemolymph osmolarities < 1050 mOsm) B. latro showed no preference for drinking fresh or seawater. When dehydrated (hemolymph osmolarities > 1050 mOsm) B. latro altered its drinking behavior and showed a distinct preference for freshwater. This strategy resulted in restoration of original hemolymph osmolarities and wet weights and was accomplished through periods of intensive drinking activity. Conversely, G. lalandii never experienced true dehydration; rather, the hemolymph became hyperosmotic compared with control animals. This species preferred freshwater both under normal and hemoconcentrated conditions. G. lalandii was also able to osmoregulate behaviorally and was able to restore hemolymph osmolarities to normal concentrations via immersion in freshwater following experimentally induced hemoconcentration. Possible physiological and ecological reasons for the differences in water uptake strategies and preferences are discussed.
在可控的实验室条件下，对椰子蟹和兰氏地蟹的饮水行为进行了录像。椰子蟹表现出在自然环境中常见的饮水行为，即用螯舀水（利斯特，1888年；格罗斯，1955年）。首次记录到兰氏地蟹也表现出同样的行为；然而，它主要通过浸泡来获取水分。在正常水合条件下（血淋巴渗透压<1050毫渗摩尔），椰子蟹对饮用淡水或海水没有偏好。当脱水时（血淋巴渗透压>1050毫渗摩尔），椰子蟹改变其饮水行为，明显偏好淡水。这种策略导致血淋巴渗透压和湿重恢复到原来水平，这是通过高强度饮水活动阶段实现的。相反，兰氏地蟹从未经历过真正的脱水；相反，与对照动物相比，其血淋巴变得高渗。该物种在正常和血液浓缩条件下都偏好淡水。兰氏地蟹也能够通过行为进行渗透调节，并且在实验诱导血液浓缩后，通过浸泡在淡水中能够将血淋巴渗透压恢复到正常浓度。文中讨论了水分摄取策略和偏好差异可能的生理和生态原因。
