Age and growth of Sebastes vulpes in the coastal waters of western Hokkaido, Japan |
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| Authors: | Takeshi SEKIGAWA Toyomi TAKAHASHI Tetsuya TAKATSU Syuichi NISHIUCHI Masayoshi SASAKI AND Fumiyasu SHIOKAWA |
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| Affiliation: | Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, ;Hokkaido Central Fisheries Experimental Station, Yoichi, Hokkaido 046-8555 and ;Hokkaido Shiribeshi-nanbu Fisheries Extension Office, Iwanai, Hokkaido 045-0023, Japan |
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| Abstract: | ABSTRACT: Age and growth of Sebastes vulpes collected from the coastal waters of western Hokkaido were studied. Observation of the otolith margin verified that annuli (outer margins of the opaque zone) were produced chiefly from July to August. This period was associated with parturition and the birth season. The maximum age estimated by the surface method was 12 years but the oldest fish was aged at 35 years by the cross-section method. The surface method was inadequate for aging of S. vulpes older than 6 years because of the underestimation of age. No significant difference was found in the parameters of the growth equations between both sexes. The von Bertalanffy growth curve combined for both sexes was as follows: SL t = 358.6(1 − exp−0.156( t +0.820)), where SL t is standard length (mm) at age t (after parturition in years). It seems likely that S. vulpes grows slowly and lives longer than previously thought. |
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| Keywords: | age cross-section method growth otolith Sebastes vulpes |
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