Maintained Cardiac Pumping in Anoxic Crucian Carp

Abstract

Like most vertebrates, humans die within minutes when deprived of molecular oxygen (anoxia), in part because of cardiac failure. In contrast, some freshwater turtles can survive anoxia for months at low temperatures, but to do so, they drastically suppress cardiac activity and autonomic cardiovascular control. Although Carassius carassius, the crucian carp, shares this anoxia tolerance, we show that it has a unique ability among vertebrates to retain normal cardiac performance and autonomic cardiovascular regulation for at least 5 days of anoxia. These responses point to an unusual tolerance of a vertebrate heart and autonomic nervous system to prolonged anoxia.

Predator-induced morphology enhances escape locomotion in crucian carp

“…In Scandinavian lakes and ponds, pike and crucian carp often coexist (Brö nmark & Miner 1992). Predation pressure on crucian carp can vary greatly within one prey generation due to hypoxic events which may kill pike and other predators, but not crucian carp, since they are extremely resistant to hypoxia (Stecyk et al 2004). Phenotypic plasticity allows crucian carp to take advantage of a shallow body form for high cruising ability in the absence of predators, while the deep-bodied morph shows a high escape swimming performance, together with a defence mechanism in the presence of gape-limited predators.…”

Identification and characterization of hypoxia-induced genes in Carassius auratus blastulae embryonic cells using suppression subtractive hybridization

“…Both in nature and in the laboratory, they have been found to survive many days or, at low temperatures, even several months of anoxia Piironen and Holopainen, 1986;Nilsson and Lutz, 2004). Some of the adaptive mechanisms the Carassius species have evolved to survive anoxia include the ability of producing ethanol as an alternative metabolic end product (Shoubridge and Hochachka, 1980;Johnston and Bernard, 1983), increasing respiratory surface area to boost oxygen uptake (Sollid et al, 2003(Sollid et al, , 2005, maintaining heart activity and brain ATP levels for several days (Nilsson, 2001;Stecyk et al, 2004). These striking differences in anoxic survival strategy are reflected all the way down to the cellular and molecular levels.…”

Critical oxygen levels and metabolic suppression in oceanic oxygen minimum zones

“…This exciting finding suggests that cyprinids are not the only fishes that produce ethanol as an anaerobic end-product and represents a novel physiological adaptation to OMZs. Ethanol is a volatile end-product that can be excreted directly across the gills, along with the CO 2 that is simultaneously produced, thereby avoiding several of the disadvantages of anaerobic metabolism (Stecyk et al, 2004). However, the energy contained in the excreted ethanol is lost.…”

“…Anaerobic glycolysis results in the accumulation of protons as well as organic compounds such as lactate and octopine (Hochachka and Somero, 2002), so consideration must be given to acid-base disturbances (Hochachka and Mommsen, 1983). Some anaerobic pathways also produce volatile end-products that can be excreted directly across the gills, allowing their continued use without risk of acid-base disturbance (Stecyk et al, 2004). However, the remaining energy contained in the volatile end-products (e.g.…”