The heart rate, oxygen consumption, survivorship, and 1-lactate
accumulation were determined in the intertidal limpets Collisella pelta
and Collisella digitalis in relation to laboratory desiccation at 15°C
or 30°C. Water loss was computed as a percentage of total initial body
water (wet weight - dry weight). Although water was lost faster in C.
digitalis than in C. pelta, C. digitalis tolerated more water loss and
survived longer than C. pelta at both experimental temperatures. During
the first few hours of desiccation at 15°C the heart rate of C. digitalis
was constant while in C. pelta the heart rate declined rapidly. During
desiccation at 30°C the heart rates of both species declined rapidly.
No change was noted in control heart rates, determined under moist
aerial conditions, in either species during a 40 hour exposure period.
Oxygen consumption of C. digitalis declined gradually during desiccation
at 15°C to about 60% of the undesiccated aerial control rate after 46
hours of exposure. During desiccation at 30°C the decline in oxygen
consumption was much more pronounced. In C. pelta during desiccation
at 15°C oxygen consumption progressively declined with increasing
length of exposure to approximately 50% of control rates for the first
16 hours of exposure at which time rates became constant. At 30°C a
more pronounced reduction in oxygen consumption occurred. Whole-body
lactate accumulated in both species during desiccation at 15°C and 30°C
in comparison with controls. At 15°C accumulation in C. pelta began
after 15 hours of desiccation while at 30°C accumulations were evident
after 4 hours. In contrast, C. digitalis gradually accumulated lactate
during the entire length of exposure to desiccation conditions at 15°C.
Upon exposure to moist nitrogen atmosphere both species exhibited
a rapid bradycardia. Heart rates recovered rapidly after exposure and
overshot pre-exposure rates indicating oxygen debt repayment.
Of the three anaerobic end products examined (alanine, succinate
and lactate) only lactate accumulated to any degree in either species
during anoxia. During anoxia C. digitalis accumulated more lactate than
C. pelta. C. pelta reached a maximum accumulation after 4 hours of
anoxia while C. digitalis continued to accumulate lactate over the
entire length of exposure to moist nitrogen.
The results suggest differences between C. digitalis and C. pelta
in metabolic adaptations which may be related to intertidal zonational
differences. / Graduation date: 1979
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28521 |
| Date | 15 March 1979 |
| Creators | Boese, Bruce Leon |
| Contributors | Pritchard, Austin W. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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