Underwater breathing: the mechanics of plastron respiration

The rough, hairy surfaces of many insects and spiders serve to render them water-repellent; consequently, when submerged, many are able to survive by virtue of a thin air layer trapped along their exteriors. The diffusion of dissolved oxygen from the ambient water may allow this layer to function as...

Full description

Saved in:
Bibliographic Details
Published in:Journal of fluid mechanics 2008-08, Vol.608, p.275-296
Main Authors: FLYNN, M. R., BUSH, JOHN W. M.
Format: Article
Language:English
Subjects:
Biochemistry. Physiology. Immunology
Biological and medical sciences
Biomimetics
Carbon dioxide
Dissolved oxygen
Environmental conditions
Fluid mechanics
Fundamental and applied biological sciences. Psychology
Gas flow
Insecta
Insects
Invertebrates
Mass transfer
Physiology. Development
Respiration
Streams
Underwater
Water
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The rough, hairy surfaces of many insects and spiders serve to render them water-repellent; consequently, when submerged, many are able to survive by virtue of a thin air layer trapped along their exteriors. The diffusion of dissolved oxygen from the ambient water may allow this layer to function as a respiratory bubble or ‘plastron’, and so enable certain species to remain underwater indefinitely. Maintenance of the plastron requires that the curvature pressure balance the pressure difference between the plastron and ambient. Moreover, viable plastrons must be of sufficient area to accommodate the interfacial exchange of O2 and CO2 necessary to meet metabolic demands. By coupling the bubble mechanics, surface and gas-phase chemistry, we enumerate criteria for plastron viability and thereby deduce the range of environmental conditions and dive depths over which plastron breathers can survive. The influence of an external flow on plastron breathing is also examined. Dynamic pressure may become significant for respiration in fast-flowing, shallow and well-aerated streams. Moreover, flow effects are generally significant because they sharpen chemical gradients and so enhance mass transfer across the plastron interface. Modelling this process provides a rationale for the ventilation movements documented in the biology literature, whereby arthropods enhance plastron respiration by flapping their limbs or antennae. Biomimetic implications of our results are discussed.
ISSN:0022-1120
1469-7645
DOI:10.1017/S0022112008002048