Temperature Effects on Blood-Oxygen Equilibria in Relation to Movements of the Bat Ray, Myliobatis californica in Tomales Bay, California
Hopkins TE and Cech JJ. 1995. Temperature Effects on Blood-Oxygen Equilibria in Relation to Movements of the Bat Ray, Myliobatis californica in Tomales Bay, California. Marine Behaviour and Physiology. 24(4):227-235
In vitro blood-oxygen binding curves for the bat ray, Myliobatis californica, were constructed at four temperatures (8, 14, 20, and 26 degree C) to gain insight into the possible adaptations to ambient temperature regimes in Tomales Bay, California. The curves were hyperbolic (man n sub(50): 1.06) with high affinities (p sub(50): 0.8-3.2 kPa) and large whole blood buffer values ( beta : -14.25 to -16.43 slykes) implying a tolerance to hypoxia and hypercapnia while large O sub(2) capacities (CBO sub(2): 3.1-4.1 mmol/L) and Bohr factors ( Phi : -0.45 to -0.52) indicated high activity levels. The temperature effect ( Delta H) was greatest between 14 and 20 degree C as compared to relatively temperature independent binding between the 8 to 14 degree C, and 20 to 26 degree C ranges. The heightened sensitivity between 14 and 20 degree C parallels a previously-documented large change in respiratory demand for this same temperature range (Q sub(10) = 6.81). However, the magnitude of the hematological adjustments were small relative to the large increase in metabolic demand and it is likely that increasing cardiac output plays an important role to safeguard oxygen transport as temperature rises. Thus, the movements of rays between warmer and cooler regions of Tomales Bay are not related to their blood oxygen binding characteristics, but may be due to other factors such as increasing assimilation efficiency, minimizing energy expenditure, or social factors.
- Type
- Journal Article
- Authors
- Hopkins, T; Cech, J
- Units
- PORE
- Keywords
- Behavior, behavioral responses, blood circulation, California, community studies, Ecology, ecophysiology, Environmental Regime Marine, Fish physiology, INE, Local movements, Marine Fish, movements ER, Myliobatis californica, temperature effects, Tomales Bay, USA