Water and ion balance and nitrogenous excretion as limitations to terrestrial excursion in the Christmas Island blue crab, Cardisoma hirtipes (Dana)
Water and ion balance and nitrogenous excretion as limitations to terrestrial excursion in the Christmas Island blue crab, Cardisoma hirtipes (Dana)
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水和离子平衡以及氮排泄对圣诞岛蓝蟹 Cardisoma hirtipes (Dana) 陆地迁移的限制
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
S. Morris
中科院分区：
文献类型：
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作者：
J. Dela;S. Morris
从物种分布上看，毛足Cardisoma hirtipes依赖淡水。C.在实验室和在潮湿和干燥季节的现场，评估了在没有自由水（螃蟹可以浸没在其中的水）的情况下，硬足蟹维持离子和水平衡以及氮排泄的能力。在强制暴露于空气中9天（仅提供饮用水），血淋巴和尿液的渗透压和组成保持恒定，尽管尿液的组成与血淋巴不同。触角腺对尿液中的Ca和Mg有重吸收作用。最终排泄产物（P）是稀释的，仅含血淋巴中测得离子浓度的10%。通过减少P流使水流失到空气中最小化，但饮水不足以防止脱水。因此，C.多毛类动物可能需要定期浸泡，以保持长期的水分平衡。与向水中的排泄相比，向空气中的氮排泄可以忽略不计，并且在空气C中9天后。在第一个2分钟内的淹没，多毛的N排泄率升高。在该领域，螃蟹限制获得水的尿液和血淋巴渗透压和组成类似的不受限制，自由放养的螃蟹。渗透压是最高的螃蟹采样在潮湿的季节，虽然氮的排泄率是相似的，在潮湿和干燥的季节自由放养和限制螃蟹。C.硬足类动物依赖水的供应，但在潮湿条件下，饮用水和食物中的水可能会抵消短期损失。C.硬足类由于氮排泄依赖于水而受到限制。J. Exp. Zool.279：537-548，1997.© 1997 Wiley-Liss，Inc.
Cardisoma hirtipes appears from the species distribution to be dependent on fresh water. The ability of C. hirtipes to maintain ion and water balance and nitrogenous excretion in the absence of free water (water in which the crab can immerse itself) was assessed in the laboratory and in the field during both the wet and dry seasons. During enforced exposure to air for 9 days (only drinking water provided), the osmotic pressure and composition of both the haemolymph and urine remained constant, although the urine differed in composition to the haemolymph. The antennal gland reabsorbed Ca and Mg from the urine. The final excretory product (P) was dilute, containing only 10% of the concentration of ions measured in the haemolymph. Water loss to air was minimised by reduced P flow, but drinking was insufficient to prevent dehydration. Therefore, C. hirtipes might require periodic immersion to maintain long-term water balance. Nitrogen excretion to air was negligible compared to excretion to water, and after 9 days in air C. hirtipes excreted N at an elevated rate within the first 2 min of submersion. In the field, crabs restricted from access to water had urine and haemolymph osmotic pressure and composition similar to unrestricted, free-ranging crabs. The osmotic pressure was highest in crabs sampled in the wet season, although nitrogenous excretion rates were similar during the wet and dry season for both free-ranging and restricted crabs. The distribution of C. hirtipes is dependent on water availability, but under humid conditions water from drinking and food might balance short-term losses. The extent of terrestrial excursions by C. hirtipes is limited by dependency on water for nitrogen excretion. J. Exp. Zool. 279:537–548, 1997.© 1997 Wiley-Liss, Inc.