2014年4月
Growth-related morphology of "Kunimasu" (Oncorhynchus kawamurae: family Salmonidae) from Lake Saiko, Yamanashi Prefecture, Japan
ICHTHYOLOGICAL RESEARCH
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- 巻
- 61
- 号
- 2
- 開始ページ
- 115
- 終了ページ
- 130
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1007/s10228-013-0382-7
- 出版者・発行元
- SPRINGER JAPAN KK
Biological characteristics of "Kunimasu" (Oncorhynchus kawamurae), poorly known even before the species was prematurely believed extinct, have now become apparent following the examination of 59 specimens from Lake Saiko, Yamanashi Prefecture, Japan and comparison with 58 examples of "Himemasu" (kokanee of Oncorhynchus nerka in Japan), also from Lake Saiko. Significant (p < 0.01) differences between Kunimasu and Himemasu from Lake Saiko occurred in counts of anal-fin rays, pectoral-fin rays, gill rakers (no overlap found) and pyloric caeca. Secondary sexual characters related to maturity level were also found in Kunimasu, the body being more compressed in pre-spawning and spawning males and females than in immature and maturing individuals. Furthermore, maturing male Kunimasu and Himemasu also differed in body shape. Body coloration of Kunimasu also differed according to level of maturity, the nuptial coloration in both sexes being olive-green when alive and black when fresh. Dark dots, found in ca. 40 % of Kunimasu individuals examined, were less distinct than in Himemasu. The spawning season of Kunimasu extended through winter and early spring in Lake Saiko, with spawning males and females remaining near the bottom, compared with non-spawning individuals which occupied the upper and middle profundal zones in the daytime.
- リンク情報
- ID情報
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- DOI : 10.1007/s10228-013-0382-7
- ISSN : 1341-8998
- eISSN : 1616-3915
- Web of Science ID : WOS:000334418500003