spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by GRAHAM, J. B.
Right arrow Articles by STÖCKMANN, W.
Right arrow Search for Related Content
PubMed
Right arrow Articles by GRAHAM, J. B.
Right arrow Articles by STÖCKMANN, W.
Journal of Experimental Biology 129,83-106 (1987)
Published by Company of Biologists 1987

The Transition to Air Breathing in Fishes : IV. Impact of Branchial Specializations for Air Breathing on the Aquatic Respiratory Mechanisms and Ventilatory Costs of the Swamp Eel Synbranchus Marmoratus

JEFFREY B. GRAHAM 1, TROY A. BAIRD 2, and WIELAND STÖCKMANN 3

1 Physiological Research Laboratory, Scripps Institution of Oceanography, University of California, San Diego, La Folla, CA 92093, USA; Department of Zoology, University of British Columbia, Vancouver, British Columbia, V6T 2AP, Canada
2 Physiological Research Laboratory, Scripps Institution of Oceanography, University of California, San Diego, La Folla, CA 92093, USA; Institut für Anatomie und Zytobiologie der Justus-Leibig-Universität Giessen, 6300 Giessen, Federal Republic of Germany
3 Physiological Research Laboratory, Scripps Institution of Oceanography, University of California, San Diego, La Folla, CA 92093, USA

The gills, adjacent buccopharyngeal epithelium, and skin of the swamp eel Synbranchus marmoratus (Bloch) function for both aerial and aquatic respiration. Aquatic cutaneous O2 uptake occurs continuously at rates that, while dependent upon aquatic 2 tension (PwOO2), are in direct proportion to body surface area. Branchial aquatic O2 uptake takes place during intermittent ventilation which occurs in proportion to body mass. Because of reductions in the body surface area to volume ratio that occur with growth, cutaneous oxygen uptake comprises a larger percentage of the total oxygen uptake of small fish and, to compensate, large fish ventilate more. The mass exponent for total rate of oxygen uptake (Voo2) (0.894 ± 0.145) is within the range predicted from the contributions of cutaneous Voo2 (mass exponent 0.651 ± 0.167) and the number of minutes each hour that branchial ventilation occurs (0.378 ± 0.105). Hyperoxia increases cutaneous VOO2 and reduces branchial ventilation. Total Voo2 was also reduced in hyperoxia and calculations relating this to the reduction in ventilation time yield ventilatory cost estimates that increase with body size and that are high compared to those of other fish when the large component of cutaneous respiration in this species is considered. Large ventilatory costs reflect gill and branchial apparatus specialization for aerial respiration. Accessory cutaneous respiration and intermittent aquatic ventilation reduce these costs, and intermittent gill use in aquatic breathing, which is the exact analogue of the pattern for branchial respiratory use during air breathing, seems to optimize aquatic O2 uptake with minimal ventilatory cost.

Key words: air breathing, gas exchange, cutaneous respiration, body size, Synbranchus, optimization of respiratory function

Accepted on October 14, 1986






© The Company of Biologists Ltd 1987