Ice nucleation studies of two beetles from sub-antarctic South Georgia
Supercooling points of adults and larvae of the coleopterans Hydromedion sparsutum and Perimylops antarcticus at South Georgia ranged from -3.0 to -5.4°C with Perimylops freezing at c.1.6°C lower than Hydromedion. Intact excised guts from adults of both species froze c. 1°C lower than the adult inse...
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ftnerc:oai:nora.nerc.ac.uk:518125 2023-05-15T13:49:34+02:00 Ice nucleation studies of two beetles from sub-antarctic South Georgia Worland, Roger Block, William Rothery, Peter 1993-03 http://nora.nerc.ac.uk/id/eprint/518125/ https://doi.org/10.1007/BF00238543 unknown Springer Worland, Roger; Block, William; Rothery, Peter. 1993 Ice nucleation studies of two beetles from sub-antarctic South Georgia. Polar Biology, 13 (2). 105-112. https://doi.org/10.1007/BF00238543 <https://doi.org/10.1007/BF00238543> Publication - Article PeerReviewed 1993 ftnerc https://doi.org/10.1007/BF00238543 2023-02-04T19:45:31Z Supercooling points of adults and larvae of the coleopterans Hydromedion sparsutum and Perimylops antarcticus at South Georgia ranged from -3.0 to -5.4°C with Perimylops freezing at c.1.6°C lower than Hydromedion. Intact excised guts from adults of both species froze c. 1°C lower than the adult insects. Ice nucleating activity of homogenized faeces from larvae and adults of both species and excised guts were compared with three potential food plants using an ice nucleation spectrometer. Mean supercooling points of the insect materials at four concentrations in distilled water (range from 0.01 to 10 g 1−1) were significantly different (P<0.01) within species, and within life stages between species. Differences in the supercooling points of suspensions of Polytrichum alpinum (moss) and Usnea fasciata (lichen) were not significant. In general, differences between supercooling points were greater at the higher concentrations. Histograms of the supercooling points showed unimodal distributions particularly at high concentrations and greater dispersion with increased dilution. Spectra showing the concentration of active ice nucleators over the temperature range 0 to -20°C were developed. These showed that nucleation occurred as high as -2°C in faecal material and all insect samples nucleated above -3°C, whereas the plant materials nucleated between -4 and -5°C. The calculated number of ice nucleators for each material in suspension revealed low values (5.3 to 5.8 × 103) for the plants, but a greater abundance (1.3 × 105 to 1.3 × 106) in the insect samples. It is concluded that c.1000 active nucleators g−1 are required for ice nucleation to occur in these suspensions. Ice nucleator activity of a suspension of Hydromedion faeces was much reduced by heating to 75°C, suggesting a proteinaceous structure. These results are discussed in relation to ice nucleation in other insects, and it is concluded that bacteria may be responsible for the high nucleation temperatures, and hence poor supercooling, in these South Georgia ... Article in Journal/Newspaper Antarc* Antarctic antarcticus Polar Biology Natural Environment Research Council: NERC Open Research Archive Antarctic Polar Biology 13 2 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
language |
unknown |
description |
Supercooling points of adults and larvae of the coleopterans Hydromedion sparsutum and Perimylops antarcticus at South Georgia ranged from -3.0 to -5.4°C with Perimylops freezing at c.1.6°C lower than Hydromedion. Intact excised guts from adults of both species froze c. 1°C lower than the adult insects. Ice nucleating activity of homogenized faeces from larvae and adults of both species and excised guts were compared with three potential food plants using an ice nucleation spectrometer. Mean supercooling points of the insect materials at four concentrations in distilled water (range from 0.01 to 10 g 1−1) were significantly different (P<0.01) within species, and within life stages between species. Differences in the supercooling points of suspensions of Polytrichum alpinum (moss) and Usnea fasciata (lichen) were not significant. In general, differences between supercooling points were greater at the higher concentrations. Histograms of the supercooling points showed unimodal distributions particularly at high concentrations and greater dispersion with increased dilution. Spectra showing the concentration of active ice nucleators over the temperature range 0 to -20°C were developed. These showed that nucleation occurred as high as -2°C in faecal material and all insect samples nucleated above -3°C, whereas the plant materials nucleated between -4 and -5°C. The calculated number of ice nucleators for each material in suspension revealed low values (5.3 to 5.8 × 103) for the plants, but a greater abundance (1.3 × 105 to 1.3 × 106) in the insect samples. It is concluded that c.1000 active nucleators g−1 are required for ice nucleation to occur in these suspensions. Ice nucleator activity of a suspension of Hydromedion faeces was much reduced by heating to 75°C, suggesting a proteinaceous structure. These results are discussed in relation to ice nucleation in other insects, and it is concluded that bacteria may be responsible for the high nucleation temperatures, and hence poor supercooling, in these South Georgia ... |
format |
Article in Journal/Newspaper |
author |
Worland, Roger Block, William Rothery, Peter |
spellingShingle |
Worland, Roger Block, William Rothery, Peter Ice nucleation studies of two beetles from sub-antarctic South Georgia |
author_facet |
Worland, Roger Block, William Rothery, Peter |
author_sort |
Worland, Roger |
title |
Ice nucleation studies of two beetles from sub-antarctic South Georgia |
title_short |
Ice nucleation studies of two beetles from sub-antarctic South Georgia |
title_full |
Ice nucleation studies of two beetles from sub-antarctic South Georgia |
title_fullStr |
Ice nucleation studies of two beetles from sub-antarctic South Georgia |
title_full_unstemmed |
Ice nucleation studies of two beetles from sub-antarctic South Georgia |
title_sort |
ice nucleation studies of two beetles from sub-antarctic south georgia |
publisher |
Springer |
publishDate |
1993 |
url |
http://nora.nerc.ac.uk/id/eprint/518125/ https://doi.org/10.1007/BF00238543 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic antarcticus Polar Biology |
genre_facet |
Antarc* Antarctic antarcticus Polar Biology |
op_relation |
Worland, Roger; Block, William; Rothery, Peter. 1993 Ice nucleation studies of two beetles from sub-antarctic South Georgia. Polar Biology, 13 (2). 105-112. https://doi.org/10.1007/BF00238543 <https://doi.org/10.1007/BF00238543> |
op_doi |
https://doi.org/10.1007/BF00238543 |
container_title |
Polar Biology |
container_volume |
13 |
container_issue |
2 |
_version_ |
1766251709268492288 |