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Unique characteristics of the trachea of the juvenile leatherback turtle facilitate feeding, diving and endothermy

Journal of Experimental Marine Biology and Ecology

By:
, , , and
DOI: 10.1016/j.jembe.2013.10.013

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Abstract

The adult leatherback turtle Dermochelys coriacea overlaps in body size (300–500 kg) with many marine mammals, yet develops from a 50 g hatchling. Adults can dive deeper than 1200 m and have core body temperatures of 25 °C; hatchlings are near-surface dwellers. Juvenile leatherbacks have rarely been studied; here we present anatomical information for the upper respiratory tract of 3 turtles (66.7–83.0 cm straight carapace length; 33.2–53.4 kg body mass) incidentally captured by long-line fisheries. Combined with existing information from adults and hatchlings, our data show that there is an ontogenic shift in tracheal structure, with cartilaginous rings becoming broader and eventually fusing anteriorly. This ontogenic shift during independent existence is unique among extant deep-diving air breathing vertebrates. Tract wall thickness is graded, becoming progressively thinner from larynx to bronchi. In addition, cross-sectional shape becomes increasingly dorsoventrally flattened (more elliptical) from anterior to posterior. These characteristics ensure that the tract will collapse from posterior to anterior during dives. This study contains the first report of a double (= internally bifurcated) posterior section of the trachea; it is suggested that this allows continuous food movement along the esophagus without tracheal collapse. The whole upper respiratory tract (from larynx to lungs) has a vascular lining (thicker anteriorly than posteriorly) that appears to be a simple analog of the complex turbinates of birds and mammals. Our study confirmed that the leatherback tracheal structure represents a distinctive way of dealing with the challenges of diving in deep, cold sea water.

Geospatial Extents

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Unique characteristics of the trachea of the juvenile leatherback turtle facilitate feeding, diving and endothermy
Series title:
Journal of Experimental Marine Biology and Ecology
DOI:
10.1016/j.jembe.2013.10.013
Volume
450
Year Published:
2014
Language:
English
Publisher:
Elsevier
Contributing office(s):
National Wildlife Health Center
Description:
7 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Experimental Marine Biology and Ecology
First page:
40
Last page:
46
Other Geospatial:
Equatorial Pacific Ocean,
Online Only (Y/N):
N
Additional Online Files(Y/N):
N