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.

Osmoregulation, Ionic Exchange, Blood Chemistry, and Nitrogenous Waste Excretion in the Land Crab Cardisoma carnifex: A Field and Laboratory Study

Chris M. Wood and R. G. Boutilier
Biological Bulletin
Vol. 169, No. 1 (Aug., 1985), pp. 267-290
DOI: 10.2307/1541403
Stable URL: http://www.jstor.org/stable/1541403
Page Count: 24
  • Subscribe ($19.50)
  • Cite this Item
Osmoregulation, Ionic Exchange, Blood Chemistry, and Nitrogenous Waste Excretion in the Land Crab Cardisoma carnifex: A Field and Laboratory Study
Preview not available

Abstract

Cardisoma carnifex in Moorea, French Polynesia, were sampled in the field and after exposure in the laboratory to either fresh- or seawater under conditions which allowed the crabs to flush their branchial chambers with the medium but not to ventilate it. Relative to field data, ionic and osmotic status of the hemolymph was virtually unchanged by exposure to freshwater, but markedly disturbed by seawater. The crabs were capable of net Na+ and Cl- uptake from freshwater. Water sampled from natural crab burrows was essentially freshwater. It is concluded that the population was "in equilibrium" with freshwater in the wild. Net H+ uptake (= base excretion) occurred in both fresh- and seawater; in freshwater there was a 1:1 relationship between net H+ flux and strong cation minus anion flux (i.e., Na++ Mg+++ Ca+++ K+- Cl-). Unidirectional Na+ and Cl- exchanges, measured radioisotopically, were typical of euryhaline crabs in freshwater, but influxes were unusual in showing no increase in seawater. Mild dehydration caused complex alterations in these exchanges in both media, associated with small and quickly reversed changes in hemolymph composition in freshwater, but larger effects in seawater which were not reversed. High levels of ammonia in hemolymph occurred in the field but declined in the laboratory, while the level of urea was low in both situations. Both wastes were excreted into the water. Neither uric acid nor gaseous ammonia excretion were detected, and uric acid was generally not found in hemolymph. The results are discussed in relation to the ecology of this unusual animal.

Page Thumbnails

  • Thumbnail: Page 
267
    267
  • Thumbnail: Page 
268
    268
  • Thumbnail: Page 
269
    269
  • Thumbnail: Page 
270
    270
  • Thumbnail: Page 
271
    271
  • Thumbnail: Page 
272
    272
  • Thumbnail: Page 
273
    273
  • Thumbnail: Page 
274
    274
  • Thumbnail: Page 
275
    275
  • Thumbnail: Page 
276
    276
  • Thumbnail: Page 
277
    277
  • Thumbnail: Page 
278
    278
  • Thumbnail: Page 
279
    279
  • Thumbnail: Page 
280
    280
  • Thumbnail: Page 
281
    281
  • Thumbnail: Page 
282
    282
  • Thumbnail: Page 
283
    283
  • Thumbnail: Page 
284
    284
  • Thumbnail: Page 
285
    285
  • Thumbnail: Page 
286
    286
  • Thumbnail: Page 
287
    287
  • Thumbnail: Page 
288
    288
  • Thumbnail: Page 
289
    289
  • Thumbnail: Page 
290
    290