Regional and interannual variations in spawning activity of Pacific saury Cololabis saira during northward migration in spring in the north-western Pacific |
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Authors: | Y Kurita |
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Institution: | Tohoku National Fisheries Research Institute, Fisheries Research Agency, Shinhama, Shiogama, Miyagi 980-0001, Japan |
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Abstract: | Regional and interannual variations in spawning activity of Pacific saury Cololabis saira during the northward migration in spring were investigated for 1995–1997 in the north-western Pacific. Only females with a large body size (≥270–290 mm knob length) appeared to spawn. Almost all females in this cohort were actively spawning in a region of sea surface temperature ( T SS) >18° C, the proportion of active spawners appeared positively related to T SS in a region of 13° C < T SS≤ 18° C, and no females were spawning in the region of T SS≤13° C. Although this relationship between spawning activity and T SS was common in all years, the distribution of females in the large-size cohort among the regions varied interannually. Consequently, the proportion of active spawners among adult females showed considerable interannual variations. |
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Keywords: | Cololabis saira distribution interannual variations Pacific saury sea surface temperature spawning activity |
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