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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Environmental Science / Faculty of Environmental Earth Science >
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Seasonal occurrence and sexual maturation of Japanese pygmy squid (Idiosepius paradoxus) at the northern limits of their distribution
| Title: | Seasonal occurrence and sexual maturation of Japanese pygmy squid (Idiosepius paradoxus) at the northern limits of their distribution |
| Authors: | Sato, Noriyosi Browse this author | | Awata, Satoshi Browse this author | | Munehara, Hiroyuki Browse this author |
| Keywords: | cephalopod | | distribution | | Idiosepius | | overwinter | | sea current | | thermal tolerance |
| Issue Date: | Jun-2009 |
| Publisher: | Oxford Journals |
| Journal Title: | ICES Journal of Marine Science |
| Volume: | 66 |
| Issue: | 5 |
| Start Page: | 811 |
| End Page: | 815 |
| Publisher DOI: | 10.1093/icesjms/fsp145 |
| Abstract: | The distribution of aquatic animals is severely limited by water temperature. However, little is known about migration pattern, over-wintering and reproduction at the northern limits of their distribution. To investigate the sexual maturation of the Japanese pygmy squid (Idiosepius paradoxus) and its ability to survive during winter at the northern limits of its distribution, we conducted monthly collections at Usujiri in northern Japan and carried out low temperature tolerance experiments. Squids were collected only during four months in autumn and early winter. In autumn, all squids were large and sexually mature, and many egg masses were found on the surface of seagrass, whereas in early winter, only small immature squids were collected. A warm northward-flowing current reached near Usujiri in autumn. These results suggest that squids were transported by the current and some small squids were recruits that hatched at Usujiri. Field data and low temperature tolerance experiments showed that I. paradoxus can not survive in the low seawater temperature that occurs at Usujiri in winter. The migration pattern in I. paradoxus may differ from the major pattern where young fish are passively transported and never reproduce at the northern limits. |
| Rights: | This is a pre-copy-editing, author-produced PDF of an article accepted for publication in ICES Journal of Marine Science following peer review. The definitive publisher-authenticated version 66(5):811-815, June 2009 is available online at: http://dx.doi.org/10.1093/icesjms/fsp145 |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/43087 |
| Appears in Collections: | 環境科学院・地球環境科学研究院 (Graduate School of Environmental Science / Faculty of Environmental Earth Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 佐藤 成祥
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