Temperature limits to activity, feeding and metabolism in the Antarctic starfish Odontaster validus

Cold-blooded Antarctic marine species are highly stenothermal and possibly the most temperature-sensitive group on Earth. Studies to date have produced upper lethal temperatures in the range of 4 to 10 degrees C. Although invertebrates have not been acclimated to temperatures above 3 degrees C, some Antarctic fish have been acclimated to 4 degrees C. Activity competence has been evaluated in several Antarctic marine invertebrates and shown to be very sensitive to temperature, with 50% failures in the range of 1 to 3 degrees C for clams, limpets and scallops. The starfish Odontaster validus is much more capable of coping with elevated temperatures than any of these species. Turning speed increased with temperature, reaching a maximum at 7.5 degrees C. Temperature increase led to a clear hierarchy of response loss in the starfish, with lethal limits occurring at a higher temperature (15 degrees C) than loss of activity (9 degrees C) and loss of feeding competence (Specific Dynamic Action, or SDA) and coelomic oxygen level collapse both occurring at 6 degrees C. The higher temperature limit for activity than coelomic oxygen level could be explained by body design or taxonomic factors, which may also explain the markedly enhanced ability to cope with elevated temperature over other Antarctic marine species. Long-term acclimation and survival up to 6 degrees C should be possible for this species, which is important for species living on the west coast of the Antarctic Peninsula, possibly the fastest warming marine environment on Earth. The markedly higher resistance to elevated temperature and maintenance of function in a common Antarctic predator compared to the abilities of several of its prey species suggests that a warming environment could have dramatic consequences on the community-level ecological balance for large areas of the Antarctic benthos.

[1]  L. Peck,et al.  An improved desorber design for use in couloximetry , 1992 .

[2]  L. Peck,et al.  Metabolic Demand, Oxygen Supply, and Critical Temperatures in the Antarctic Bivalve Laternula elliptica , 2002, Physiological and Biochemical Zoology.

[3]  L. Peck,et al.  Slowest of the slow: latitudinal insensitivity of burrowing capacity in the bivalve Laternula , 2007 .

[4]  A. Clarke,et al.  Antarctic marine benthic diversity , 2003 .

[5]  L. Peck,et al.  Two methods for the assessment of the oxygen content of small volumes of seawater , 1990 .

[6]  L. Peck,et al.  The myth of metabolic cold adaptation: oxygen consumption in stenothermal Antarctic bivalves , 2000, Geological Society, London, Special Publications.

[7]  C. Franklin,et al.  A falsification of the thermal specialization paradigm: compensation for elevated temperatures in Antarctic fishes , 2005, Biology Letters.

[8]  L. Peck.  Temperature and basal metabolism in two Antarctic marine herbivores , 1989 .

[9]  A. Clarke,et al.  The Influence of Feeding on Oxygen Consumption and Nitrogen Excretion in the Antarctic Nemertean Parborlasia corrugatus , 1997, Physiological Zoology.

[10]  L. Peck,et al.  Mitochondrial function and critical temperature in the Antarctic bivalve, Laternula elliptica , 1999 .

[11]  G. Somero,et al.  Temperature Tolerance of Some Antarctic Fishes , 1967, Science.

[12]  H. Pörtner,et al.  Energetic aspects of cold adaptation critical temperatures in metabolic, ionic and acid-base regulation? , 1998 .

[13]  W. Davison,et al.  Plasma osmolarity, glucose concentration and erythrocyte responses of two Antarctic nototheniid fishes to acute and chronic thermal change , 2005 .

[14]  A. Devries,et al.  Antifreeze glycoprotein levels in Antarctic notothenioid fishes inhabiting different thermal environments and the effect of warm acclimation. , 2006, Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology.

[15]  M. Meredith,et al.  Rapid climate change in the ocean west of the Antarctic Peninsula during the second half of the 20th century , 2005 .

[16]  Lloyd S. Peck,et al.  Extreme sensitivity of biological function to temperature in Antarctic marine species , 2004 .

[17]  L. Peck,et al.  Thermal limits of burrowing capacity are linked to oxygen availability and size in the Antarctic clam Laternula elliptica , 2007, Oecologia.

[18]  G. Somero,et al.  Inducible heat tolerance in Antarctic notothenioid fishes , 2006, Polar Biology.

[19]  H. Hensel,et al.  Temperatur und Leben , 1955 .

[20]  L. Peck.  Metabolism and feeding in the Antarctic brachiopod Liothyrella uva: a low energy lifestyle species with restricted metabolic scope , 1996, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[21]  L. Peck,et al.  Feeding, metabolism and growth in the Antarctic limpet, Nacella concinna (Strebel 1908) , 2001 .

[22]  I. Johnston,et al.  Invertebrate muscle performance at high latitude: swimming activity in the Antarctic scallop, Adamussium colbecki , 2005, Polar Biology.

[23]  L. Peck.  Prospects for survival in the Southern Ocean: vulnerability of benthic species to temperature change , 2005, Antarctic Science.

[24]  L. Peck,et al.  Intracellular pH and energy metabolism in the highly stenothermal Antarctic bivalve Limopsis marionensis as a function of ambient temperature , 1999, Polar Biology.

[25]  C. Franklin,et al.  Turning up the heat on subzero fish: thermal dependence of sustained swimming in an Antarctic notothenioid , 2002 .

[26]  G. Somero,et al.  Thermal limits and adaptation in marine Antarctic ectotherms: an integrative view , 2007, Philosophical Transactions of the Royal Society B: Biological Sciences.

[27]  L. Peck,et al.  The influence of acclimation and substratum on the metabolism of the Antarctic amphipods Waldeckia obesa (Chevreux 1905) and Bovallia gigantea (Pfeffer 1888) , 1995, Polar Biology.

[28]  P. Gonzalez-Cabrera,et al.  Enhanced hypo-osmoregulation induced by warm-acclimation in antarctic fish is mediated by increased gill and kidney Na+/K(+)-ATPase activities. , 1995, The Journal of experimental biology.