Effects of environmental factors and body size on rates of oxygen consumption in Archaeomysis grebnitzkii and Neomysis awatschensis (Crustacea: Mysidae)

The rates of oxygen consumption in relation to oxygen tension, temperature, salinity and body size were determined for Archaeomysis grebnitzkii Czerniavsky and Neomysis awatschensis (Brandt). Oxygen uptake was regulated by both species down to an oxygen tension of about 50 mm Hg (30% of saturation value); below this level, it was related to the oxygen tension in the medium. Oxygen tension below 20 mm Hg was lethal. A statistically significant interaction was noted for the effects of species, temperature, and salinity. In general, oxygen-uptake rate decreased with decreasing salinity in both species. The effect of size is expressed as a power function of body weight. The regression coefficients of oxygen consumption on body weight, 0.70 for A. grebnitzkii and 0.62 for N. awatschensis, were found to be significantly different from each other.Contribution No. 726 from the Department of Oceanography, University of Washington, Seattle, USA.