Typescript.
Includes vita and abstract.
Bibliography: Includes bibliographical references (leaves 172-183). / Cancer magister, the Dungeness crab, occurs in
different habitats during its life cycle, habitats which
vary widely in the magnitude of salinity and temperature
changes. Cancer magister hemocyanin also changes in
structure and oxygenation properties during development. The
following question was considered in this thesis: what are
the effects of environmental salinity and temperature on
metabolic rates, ionic and osmotic regulation and hemocyanin
oxygen affinity in Q. magister during development.
Metabolic rates and hemolYmph ionic and osmotic
concentrations were measured in the megalopa, 1st juvenile,
5th juvenile and adult crab eight hours after acute exposure
to 100% seawater (=32 ppt), 75% seawater and 50% seawater at
both 10°C and 20°C. The oxygen binding properties of the
whole hemolymph from these stages in 100% seawater at 10°C was determined. The effects of calcium and magnesium on the
oxygen affinity of purified hemocyanin from different stages
were also determined.
In 100% seawater, routine metabolic rates of the four
stages scale with body mass over the size range, 0.05 gm to
500 gm. The Q10 (10°C to 20°C) for the megalopa is higher in
75% seawater and 50% seawater than in 100% seawater. For the
1st juvenile, 5th juvenile and adult the Q10 values (10°C to
20°C) are independent of salinity. The megalopa, 1st
juvenile and 5th juvenile are weaker regulators of hemolymph
chloride, sodium and osmotic concentrations than the adult.
The megalopa and adult, unlike the 1st juvenile and 5th
juvenile, strongly regulate hemolymph calcium in reduced
salinity. In 100% seawater hemolymph magnesium is
significantly higher in the megalopa, 1st juvenile and 5th
juvenile than in the adult. The oxygen affinities of whole
hemolymph from the four stages are indistinguishable when
adjusted for endogenous L-lactate concentrations; the Bohr
coefficients are not significantly different among stages.
The effect of magnesium on oxygen affinity of purified adult
hemocyanin is influenced by proton concentration; the effect
of calcium is independent of proton concentration. In 100%
seawater, endogenous inorganic ion concentrations in the
whole hemolymph of the various stages reduce the intrinsic
stage specific differences in hemocyanin oxygen affinity.
| Identifer | oai:union.ndltd.org:uoregon.edu/oai:scholarsbank.uoregon.edu:1794/9845 |
| Date | January 1991 |
| Creators | Brown, Anne Christine, 1962- |
| Publisher | Thesis (Ph. D.)--University of Oregon, 1991. |
| Source Sets | University of Oregon |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
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