Alterations in soluble/insoluble collagen ratios in the annual fish, Cynolebias bellottii, in relation to age and environmental temperature

Abstract Annual fish of the species Cynolebias bellottii have a prolonged survival when kept throughout most of their lives at 15°C, as opposed to 20°C. The prolonged survival is accompanied by changes in the ratio of soluble to insoluble collagen of such a nature as to suggest an actual retardation of the ageing process. It is known that reduced temperature in poikilotherms constitutes a potent immunosuppressive regime. The results are therefore consistent with theoretical expectations of the immunologic theory of ageing.