Decline in Pelagic Cephalopod Metabolism With Habitat Depth Reflects Differences in Locomotory Efficiency

摘要: The metabolic rates of 33 species pelagic cephalopods from California and Hawaii were measured correlated with minimum depth occurrence. Mean ranged 0.07 {mu}mol O2g-1 h-1 for the deep-living vampire squid, Vampyroteuthis infernalis, to 8.79 O2 g-1 Gonatus onyx, a vertically migrating squid. An individual V. which lives within oxygen layer off California, had lowest mass-specific rate ever cephalopod (0.02 h-1, 1050 g wet weight). For collected in sufficient quantity size range, metabolism was related body size. Critical partial pressures (Pc) determined Hawaiian Californian cephalopods. Pc values animals considerably higher than those taken trend that corresponds levels environmental waters. Buffering capacity ({beta}) mantle muscle, assayed eight species, used estimate glycolytic energy production. {beta} 1.43 slykes bathypelagic octopod, Japetella heathi, 77.08 an epipelagic Sthenoteuthis oualaniensis. Significant declines increasing occurrence observed both {beta}. decline parameters is interpreted as decreased reliance on locomotory abilities predator/prey interactions light-limited deep sea. significantly steeper previously either fishes or crustaceans. We suggest since strong are not priority sea, deeper-living may rely more heavily means locomotion efficient jet propulsion via contractions--means such fin swimming medusoid utilizing arms extensive webbing present many species. greater efficiency be responsible observation pronounced