QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by TAYLOR, H. H. Articles by GREENAWAY, P. Search for Related Content PubMed Articles by TAYLOR, H. H. Articles by GREENAWAY, P.

Journal of Experimental Biology 111,103-121 (1984)
Published by Company of Biologists 1984

The Role of the Gills and Branchiostegites in Gas Exchange in a Bimodally Breathing Crab, Holthuisana Transversa: Evidence for a Facultative Change in the Distribution of the Respiratory Circulation

H. H. TAYLOR ¹ and PETER GREENAWAY ²

¹ Department of Zoology, University of Canterbury, Christchurch, New Zealand
² School of Zoology, University of New South Wales, Kensington, New South Wales, Australia

The respiratory circulation was investigated in air-breathing and waterbreathing Holthuisana transversa von Martens by analysis of the distribution of radioactive microspheres injected into the haemocoel at seven locations. The gills and putative lungs (branchiostegites and membraneous thoracic walls) both trap approximately 90% of the microspheres entrained in their afferent circulations. The main blood supply to the branchiostegites is from the venous sinuses and constitutes a substantial fraction of the total venous return, which is consistent with earlier inferences, based on morphological information, of their possible involvement in gas exchange. In airbreathing crabs, a mechanism exists which directs a greater proportion of the total venous return via the lungs. From the sinus at the base of walking leg 2, the ratio lung: gill flow was estimated as 86.9: 13.1 ± 5.7% in hydrated crabs that had been air-breathing for more than 1 day, and 19.5:80.5 ± 7.12% in water-breathers. A factor in this circulatory switch may be an increase in branchial resistance in air caused by surface tension of water adherent to the gill lamellae. The direct arterial circulation to the gills represents about 3% of cardiac output and is therefore an insignificant component of the total respiratory circulation. Patterns of microsphere distribution among different gills and different regions of the lung provide information on flow patterns within the thoracic sinus. Neither the thoracic sinus as a whole nor the inf rabranchial sinuses can be considered as reservoirs of truly mixed venous blood in H. transversa.

Key words: Land crab, gas exchange, respiratory circulation

Accepted on February 3, 1984

This article has been cited by other articles:

				N. L. C. Ragg and H. H. Taylor Heterogeneous perfusion of the paired gills of the abalone Haliotis iris Martyn 1784: an unusual mechanism for respiratory control J. Exp. Biol., February 1, 2006; 209(3): 475 - 483. [Abstract] [Full Text] [PDF]

				S. Morris Respiratory and acid-base responses during migration and to exercise by the terrestrial crab Discoplax (Cardisoma) hirtipes, with regard to season, humidity and behaviour J. Exp. Biol., November 15, 2005; 208(22): 4333 - 4343. [Abstract] [Full Text] [PDF]