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Document Description
TitleThe role of antifreeze compounds in inhibiting ice crystal growth across the skin of marine fishes
AuthorValerio, Paul F.(Paul Federico), 1957-
DescriptionThesis (M.Sc.)--Memorial University of Newfoundland, 1992. Biology
Paginationvii, 83 leaves : ill.
SubjectCryobiochemistry; Fishes--Effect of temperature on; Cold adaptation; Marine fishes--Physiology
Degree GrantorMemorial University of Newfoundland. Dept. of Biology.
NotesBibliography: leaves 75-83
AbstractIt has been well established that antifreeze peptides are responsible for the ability of many marine teleosts to survive in icy sea water at temperatures below the colligative freezing points of their blood. However the in vivo site of antifreeze action has yet to be determined. The "ice-exclusion hypothesis" suggests that antifreeze proteins act within epithelial membranes (skin, gills, gut) and block the entry of external ice crystals. This hypothesis was examined by measuring ice propagation temperatures across isolated skin samples from the winter flounder (Pleuronectes americanus). The results obtained were consistent with the hypothesis, indicating that fish skin is an effective barrier to ice propagation and that the effectiveness of this barrier improves with the addition of antifreeze proteins. The results also demonstrated that the skin ice propagation temperatures were substantially lower than the lethal freezing temperatures of the fish. Therefore, some other epithelial tissue (possible gill) must be less effective than the skin in blocking ice crystal penetration into the fish. -- Analysis of tissues from the cunner, Tautociolabrus adspersus, revealed the presence of a thermal hysteresis compound in aqueous extracts of the skin. The apparent absence of this substance from cunner plasma provided further support for the hypothesis that antifreeze proteins block the entry of external ice crystals into the fish.
Resource TypeElectronic thesis or dissertation
FormatImage/jpeg; Application/pdf
SourcePaper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries
Local Identifier76118650
RightsThe author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission.
CollectionElectronic Theses and Dissertations
Scanning StatusCompleted
PDF File(10.08 MB) --
CONTENTdm file name337178.cpd