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Chloride ion and water balance in the prosobranch gastropod Collisella persona

The chloride ion concentration of blood, urine, and foot muscle, blood and muscle water content, and blood and urine osmotic pressure, were measured in summer and winter adapted populations of the prosobranch limpet Collisella persona, over a range of salinities from 25% to 125% SW (100% SW = 480 mEq Cl⁻/L). Blood, urine, and foot muscle Cl⁻ were not regulated in all salinities tested. Blood Cl⁻ was generally hypoionic and urine isoionic to the experimental sea water concentrations. Muscle Cl⁻ did not reach a level greater than one-half of equivalent blood or sea water values in all salinities tested. However, muscle and blood values were similar, if muscle Cl⁻ were expressed in terms of extracellular water. Extracellular volume remained relatively unchanged and showed only a 7% increase in salinities ranging from 50% to 125% SW. Seasonal differences were apparent in muscle Cl⁻, with winter values higher than summer values by 20-25 mEq/kg tissue, in salinities ranging from 75% to 125% SW. However, this could be accounted for by the slightly larger (4-8%) extracellular space recorded from winter animals.
Summer and winter adapted limpets were osmoconformers in salinities ranging from 25% to 125% SW. Summer animals had blood hyperosmotic, and urine isosmotic to the experimental sea water concentrations. Winter limpets had blood hyperosmotic to 75% SW, and isosmotic in 25% and 125% SW. Urine was hyposmotic to 25% and 75% SW, and isosmotic in 125% SW. Summer blood was hyperosmotic to winter blood, although summer and winter urine

remained isosmotic. In addition, for both summer and winter animals, blood was hyperosmotic to urine.
The foot muscle water content of winter adapted limpets returned to the control value in 50% to 125% SW, between 48 hours and 1 week. Over the same time period, summer animals only regulated muscle water in 50% and 75% SW. Blood water content remained relatively unchanged for both summer and winter adapted limpets, and showed a 4% decrease over a salinity range from 25% to 125% SW. There were no significant seasonal differences in blood water content.
Seasonal differences recorded during the present study, in particular the comparatively large variation in measurements from summer animals, were attributed to seasonal changes in salt and water permeability, or metabolic rate. In addition, an attempt was made to relate the physiological responses recorded from limpets in the laboratory, to the survival of limpets in the field. / Science, Faculty of / Zoology, Department of / Graduate

Identiferoai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/23127
Date January 1982
CreatorsClark, Geoffrey A.
Source SetsUniversity of British Columbia
LanguageEnglish
Detected LanguageEnglish
TypeText, Thesis/Dissertation
RightsFor non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.

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