Summary: | Oxygen consumption of the copepodid V stages of Calanas plumchras was studied with respect to environmental and endogenous factors using standard closed chamber technique and Warburg respirometry. Specimens were collected from San Juan Channel, Washington and Indian Arm, British Columbia.
Rate of oxygen consumption of C, plumchrus (1) is significantly
decreased by population densities of 5 or more copepods / ml, (2) demonstrates no regular endogenous change, (3) is not significantly affected by presence or absence of light, (4) is directly proportional to temperature (being variously linear and non-linear in response) throughout the range of 5-20° C, (5) does not vary significantly over a salinity range of 20-35 ppt (but during May 1965 increased at 10 ppt and decreased at 45 ppt), (6) decreases to a minimum below an ambient oxygen concentration of 3 co 0₂ per liter and (7) is not significantly affected by increased hydrostatic pressure corresponding to a depth of about 400 m. Response to a range of temperatures, in particular, indicates that oxygen measurements taken from different collections are statistically different and therefore not directly comparable.
In general, the data presented are consistent with McLaren's theory of energy utilization and vertical migration, although temperature does not always appear to be the most significant factor. Interaction and variation of environmental factors may explain some of the complexity of vertical migration. === Science, Faculty of === Zoology, Department of === Graduate
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