Growth and Development of Spirula Spirula
Spirula spirula has stimulated considerable interest since it was first discovered. It is a member of one of the two genera of sepioids to frequent oceanic water (the other being Heteroteuthis ); it has a unique spiral shell which acts as a buoyancy mechanism and can withstand considerable pressure...
Published in: | Journal of the Marine Biological Association of the United Kingdom |
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Language: | English |
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Cambridge University Press (CUP)
1970
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Online Access: | http://dx.doi.org/10.1017/s002531540000059x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002531540000059X |
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crcambridgeupr:10.1017/s002531540000059x 2024-06-16T07:41:55+00:00 Growth and Development of Spirula Spirula Clarke, M. R. 1970 http://dx.doi.org/10.1017/s002531540000059x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002531540000059X en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Journal of the Marine Biological Association of the United Kingdom volume 50, issue 1, page 53-64 ISSN 0025-3154 1469-7769 journal-article 1970 crcambridgeupr https://doi.org/10.1017/s002531540000059x 2024-05-22T12:55:59Z Spirula spirula has stimulated considerable interest since it was first discovered. It is a member of one of the two genera of sepioids to frequent oceanic water (the other being Heteroteuthis ); it has a unique spiral shell which acts as a buoyancy mechanism and can withstand considerable pressure (Denton, Gilpin-Brown & Howarth, 1967); and, until the capture by the Danish Oceanographical expeditions it was considered very rare, only 12 specimens having been captured. The Dana expeditions caught 193 individuals from 1909 to 1931 and these were described by Kerr (1931) and Bruun (1943,1955). Most of these were caught in the waters around the Canary Islands of the North Atlantic. Bruun (1943) arranged the specimens according to month and size and claimed that two size groups could be distinguished. The specimens were taken over a wide geographical area, in several years and during the months of February (1 specimen), March (40), April (3), May (8), June (1), August (1) and October (23). His conclusion concerning growth depends entirely upon his decision to split the March sample into two year-groups; those above 1.9 cm in ventral mantle length he put in a separate year-class to those below 1.9 cm in ventral mantle length. This division was arbitrary and, one suspects, based on a belief that a one-year life-span was likely. Clearly the growth of Spirula requires further study based on a larger collection and the present paper is an attempt to fulfil this need. MATERIAL AND METHODS This work is based upon 256 specimens collected to the south-east of Fuerteventura in the Canary Islands by R.R.S. ‘Discovery’ during 1965–68. Article in Journal/Newspaper North Atlantic Cambridge University Press Kerr ENVELOPE(65.633,65.633,-70.433,-70.433) Journal of the Marine Biological Association of the United Kingdom 50 1 53 64 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Spirula spirula has stimulated considerable interest since it was first discovered. It is a member of one of the two genera of sepioids to frequent oceanic water (the other being Heteroteuthis ); it has a unique spiral shell which acts as a buoyancy mechanism and can withstand considerable pressure (Denton, Gilpin-Brown & Howarth, 1967); and, until the capture by the Danish Oceanographical expeditions it was considered very rare, only 12 specimens having been captured. The Dana expeditions caught 193 individuals from 1909 to 1931 and these were described by Kerr (1931) and Bruun (1943,1955). Most of these were caught in the waters around the Canary Islands of the North Atlantic. Bruun (1943) arranged the specimens according to month and size and claimed that two size groups could be distinguished. The specimens were taken over a wide geographical area, in several years and during the months of February (1 specimen), March (40), April (3), May (8), June (1), August (1) and October (23). His conclusion concerning growth depends entirely upon his decision to split the March sample into two year-groups; those above 1.9 cm in ventral mantle length he put in a separate year-class to those below 1.9 cm in ventral mantle length. This division was arbitrary and, one suspects, based on a belief that a one-year life-span was likely. Clearly the growth of Spirula requires further study based on a larger collection and the present paper is an attempt to fulfil this need. MATERIAL AND METHODS This work is based upon 256 specimens collected to the south-east of Fuerteventura in the Canary Islands by R.R.S. ‘Discovery’ during 1965–68. |
format |
Article in Journal/Newspaper |
author |
Clarke, M. R. |
spellingShingle |
Clarke, M. R. Growth and Development of Spirula Spirula |
author_facet |
Clarke, M. R. |
author_sort |
Clarke, M. R. |
title |
Growth and Development of Spirula Spirula |
title_short |
Growth and Development of Spirula Spirula |
title_full |
Growth and Development of Spirula Spirula |
title_fullStr |
Growth and Development of Spirula Spirula |
title_full_unstemmed |
Growth and Development of Spirula Spirula |
title_sort |
growth and development of spirula spirula |
publisher |
Cambridge University Press (CUP) |
publishDate |
1970 |
url |
http://dx.doi.org/10.1017/s002531540000059x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002531540000059X |
long_lat |
ENVELOPE(65.633,65.633,-70.433,-70.433) |
geographic |
Kerr |
geographic_facet |
Kerr |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Journal of the Marine Biological Association of the United Kingdom volume 50, issue 1, page 53-64 ISSN 0025-3154 1469-7769 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s002531540000059x |
container_title |
Journal of the Marine Biological Association of the United Kingdom |
container_volume |
50 |
container_issue |
1 |
container_start_page |
53 |
op_container_end_page |
64 |
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1802009253260558336 |