Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If you need an accessible version of this item please contact JSTOR User Support

Sodium and Water Balance in Free-Ranging Robber Crabs, Birgus latro (Anomura: Coenobitidae)

Peter Greenaway
Journal of Crustacean Biology
Vol. 21, No. 2 (May, 2001), pp. 317-327
Published by: on behalf of The Crustacean Society
Stable URL: http://www.jstor.org/stable/1549783
Page Count: 11
  • Read Online (Free)
  • Download ($34.00)
  • Subscribe ($19.50)
  • Cite this Item
If you need an accessible version of this item please contact JSTOR User Support
Sodium and Water Balance in Free-Ranging Robber Crabs, Birgus latro (Anomura: Coenobitidae)
Preview not available

Abstract

The rates of exchange of sodium and water and renal filtration rates were measured in field populations of Birgus latro (Linnaeus, 1756) in rain forest on Christmas Island, Indian Ocean. Water exchange was quite high (47.7 ml· kg-1· d-1) and on seed diets must have been derived largely from drinking, although animal tissue when eaten would have provided a greater amount of preformed water. Under prevailing conditions water output was chiefly in the excretory fluid. Intake of sodium was almost entirely from the food, and the mean rate of exchange of sodium (7.8 mmol· kg-1· d-1) was too high to be satisfied from vegetable origins. The crabs clearly fed regularly on animal material, probably Red Crabs, Gecarcoidea natalis. The bulk of sodium loss occurred via the excretory fluid. The intakes of water and sodium are well above the minimum level required for the maintenance of salt and water balance and, under field conditions with access only to rain water for drinking, B. latro has a very considerable reserve of osmoregulatory capacity. Saline drinking water is not required for the maintenance of ion balance.

Page Thumbnails

  • Thumbnail: Page 
317
    317
  • Thumbnail: Page 
318
    318
  • Thumbnail: Page 
319
    319
  • Thumbnail: Page 
320
    320
  • Thumbnail: Page 
321
    321
  • Thumbnail: Page 
322
    322
  • Thumbnail: Page 
323
    323
  • Thumbnail: Page 
324
    324
  • Thumbnail: Page 
325
    325
  • Thumbnail: Page 
326
    326
  • Thumbnail: Page 
327
    327