【動画】LASBOS card 020
Neocalanus cristatus, that reaches almost 1 cm in body length, is a large copepod distributed in the subarctic North Pacific Ocean. This species occupy approximately 30% on the zooplankton biomass in the Oyashio region and is an important prey for fish, cetaceans, and seabirds. This species develops in the surface layer during spring, and after accumated energy as lipid inside their body, descent to depths greater than 1,000 m. Between summer and winter, they stay in the deep layer for their diapause. Reproduction occurs at the deep layer, and the hatched nauplii with large amounts of lipid return to the surface. This species has a one-year life cycle.
Photo: MATSUNO Kohei
Text: YAMAGUCHI Atsushi
カイアシ類 Neocalanus cristatus
Neocalanus cristatus は北太平洋亜寒帯域に分布する大型カイアシ類で、体長は1 cm弱にまで達します。本種は親潮域における動物プランクトン重量の約30%を占めて、魚類や鯨類、海鳥類の重要な餌生物です。本種は春に表層で成長し、体内に油脂として栄養を貯め込んだ後に、水深1000 m以深に潜り、夏~冬は深海で過ごす休眠期を持ちます。再生産は深海で行われ、ふ化した幼生は油分を多み、脱皮を繰り返しつつ表層に回帰する、1年の生活史を持っています。