Thermal independence of muscle tissue metabolism in the leatherback turtle, Dermochelys coriacea

Department of Bioscience and Biotechnology, Drexel University, Philadelphia, PA 19104, USA.
Comparative Biochemistry and Physiology - Part A Molecular & Integrative Physiology (Impact Factor: 1.97). 08/1998; 120(3):399-403. DOI: 10.1016/S1095-6433(98)00024-5
Source: PubMed


Metabolic rates of animal tissues typically increase with increasing temperature and thermoregulatory control in an animal is a regional or whole body process. Here we report that metabolic rates of isolated leatherback turtle (Dermochelys coriacea) pectoralis muscle are independent of temperature from 5-38 degrees C (Q10 = 1). Conversely, metabolic rates of green turtle (Chelonia mydas) pectoralis muscle exhibit a typical vertebrate response and increase with increasing temperature (Q10 = 1.3-3.0). Leatherbacks traverse oceanic waters with dramatic temperature differences during their migrations from sub-polar to equatorial regions. The metabolic stability of leatherback muscle effectively uncouples resting muscle metabolism from thermal constraints typical of other vertebrate tissues. Unique muscle physiology of leatherbacks has important implications for understanding vertebrate muscle function, and is another strong argument for preservation of this endangered species.

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Available from: Frank V Paladino
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    • "This endothermy is thought to be achieved through their considerable body mass (gigantothermy; Paladino et al. 1990) and physiological adaptations including counter-current vasculature in the flippers (Greer et al. 1973), insulating subcutaneous lipid layers (Frair et al. 1972, Davenport et al. 1990) and variable lipid composition and distribution (Davenport et al. 1990). The independence of leatherback muscle metabolism to temperatures between 5 and 38°C (Penick et al. 1998) may also favour prolonged occupation of mid-latitude habitats. Leatherback turtles primarily feed on gelatinous organisms such as coelenterates (class Scyphozoa), including Aurelia, Chrysaora, Cyanea and Rhizostoma (Bleakney 1965, Brongersma 1972, Davenport 1998). "
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