Chronological and physiological ageing in a polar and a temperate mud clam.
We investigated chronological and physiological ageing of two mud clams with regard to the "rate of living theory" (Pearl, 1928) and the "free radical theory of ageing" (Harman, 1956). The Antarctic Laternula elliptica (Pholadomyoida) and the temperate Mya arenaria (Myoida) represent the same ecotype (benthic infaunal filter feeders), but differ in maximum life span, 36 and 13 years, respectively. L. elliptica has a two-fold lower standard metabolic rate than M. arenaria, but its life long energy turnover at maximal age is three times higher. When comparing the two species within the lifetime window of M. arenaria, antioxidant capacities (glutathione, catalase) are higher and tissue oxidation (ratio of oxidised to reduced glutathione, lipofuscin accumulation) is lower in the polar L. elliptica than in the temperate mud clam. Tissue redox state in L. elliptica remained stable throughout all ages, whereas it increased dramatically in aged M. arenaria. Our results indicate that metabolic rates and maintenance of tissue redox state are major factors determining maximum lifespan in the investigated mud clams.
Philipp
Eva
E
Alfred-Wegener-Institut für Polar-und Meeresforschung, Okophysiologie, Postfach 120161, D-27568 Bremerhaven, Germany.
Brey
Thomas
T
Pörtner
Hans-Otto
HO
Abele
Doris
D
D000375:Aging / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D000864:Antarctic Regions; D049872:Bivalvia / Q000378:metabolism / Q000502:physiology*; D002374:Catalase / Q000378:metabolism; D002980:Climate; D005978:Glutathione / Q000378:metabolism; D008062:Lipofuscin / Q000378:metabolism; D009426:Netherlands; D009659:North Sea; D010084:Oxidation-Reduction; D011506:Proteins / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
D008062:Lipofuscin; D011506:Proteins; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione