Polyteny and Size Variation in the Copepod Pseudocalanus from Two Semi-Landlocked Fiords on Baffin Island
Two forms of the copepod Pseudocalanus, which differ only in size, coexist in two semi-landlocked fiords on Baffin Island. The large form possesses the same number of chromosomes as the small but its chromosomes are conspicuously larger and contain about seven times as much DNA. Due to polyteny, the...
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Canadian Science Publishing
1969
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crcansciencepubl:10.1139/f69-052 2023-12-17T10:26:16+01:00 Polyteny and Size Variation in the Copepod Pseudocalanus from Two Semi-Landlocked Fiords on Baffin Island Woods, Susan M. 1969 http://dx.doi.org/10.1139/f69-052 http://www.nrcresearchpress.com/doi/pdf/10.1139/f69-052 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Journal of the Fisheries Research Board of Canada volume 26, issue 3, page 543-556 ISSN 0015-296X General Medicine journal-article 1969 crcansciencepubl https://doi.org/10.1139/f69-052 2023-11-19T13:39:12Z Two forms of the copepod Pseudocalanus, which differ only in size, coexist in two semi-landlocked fiords on Baffin Island. The large form possesses the same number of chromosomes as the small but its chromosomes are conspicuously larger and contain about seven times as much DNA. Due to polyteny, the large form has a greater cell size and a slower development rate than the small form. The large form, having an essentially annual life cycle, matures later than the small form. Two generations of the small form may be produced in a summer with only the first reaching maturity. As the fiord waters are warmer, the small form is smaller and develops faster than its counterpart in nearby seas. The large form may represent an evolutionary attempt to restore normal arctic size and development rate in the fiords. In the cold waters of the sea, the slow development rate of the large form might lead to an excessively long life cycle, perhaps biennial. This may explain the apparent absence of the large form outside the two fiords. The polytene form may be a new species but, as the taxonomy of the genus is indefinite, a new name is deferred. Article in Journal/Newspaper Arctic Baffin Island Baffin Canadian Science Publishing (via Crossref) Arctic Baffin Island Journal of the Fisheries Research Board of Canada 26 3 543 556 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
General Medicine |
spellingShingle |
General Medicine Woods, Susan M. Polyteny and Size Variation in the Copepod Pseudocalanus from Two Semi-Landlocked Fiords on Baffin Island |
topic_facet |
General Medicine |
description |
Two forms of the copepod Pseudocalanus, which differ only in size, coexist in two semi-landlocked fiords on Baffin Island. The large form possesses the same number of chromosomes as the small but its chromosomes are conspicuously larger and contain about seven times as much DNA. Due to polyteny, the large form has a greater cell size and a slower development rate than the small form. The large form, having an essentially annual life cycle, matures later than the small form. Two generations of the small form may be produced in a summer with only the first reaching maturity. As the fiord waters are warmer, the small form is smaller and develops faster than its counterpart in nearby seas. The large form may represent an evolutionary attempt to restore normal arctic size and development rate in the fiords. In the cold waters of the sea, the slow development rate of the large form might lead to an excessively long life cycle, perhaps biennial. This may explain the apparent absence of the large form outside the two fiords. The polytene form may be a new species but, as the taxonomy of the genus is indefinite, a new name is deferred. |
format |
Article in Journal/Newspaper |
author |
Woods, Susan M. |
author_facet |
Woods, Susan M. |
author_sort |
Woods, Susan M. |
title |
Polyteny and Size Variation in the Copepod Pseudocalanus from Two Semi-Landlocked Fiords on Baffin Island |
title_short |
Polyteny and Size Variation in the Copepod Pseudocalanus from Two Semi-Landlocked Fiords on Baffin Island |
title_full |
Polyteny and Size Variation in the Copepod Pseudocalanus from Two Semi-Landlocked Fiords on Baffin Island |
title_fullStr |
Polyteny and Size Variation in the Copepod Pseudocalanus from Two Semi-Landlocked Fiords on Baffin Island |
title_full_unstemmed |
Polyteny and Size Variation in the Copepod Pseudocalanus from Two Semi-Landlocked Fiords on Baffin Island |
title_sort |
polyteny and size variation in the copepod pseudocalanus from two semi-landlocked fiords on baffin island |
publisher |
Canadian Science Publishing |
publishDate |
1969 |
url |
http://dx.doi.org/10.1139/f69-052 http://www.nrcresearchpress.com/doi/pdf/10.1139/f69-052 |
geographic |
Arctic Baffin Island |
geographic_facet |
Arctic Baffin Island |
genre |
Arctic Baffin Island Baffin |
genre_facet |
Arctic Baffin Island Baffin |
op_source |
Journal of the Fisheries Research Board of Canada volume 26, issue 3, page 543-556 ISSN 0015-296X |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f69-052 |
container_title |
Journal of the Fisheries Research Board of Canada |
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26 |
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3 |
container_start_page |
543 |
op_container_end_page |
556 |
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1785577982396465152 |