Seasonal migration and diel vertical migration of the neon flying squid, Ommastrephes bartramii in the North Pacific
Murata, M.; Nakamura, Y. (1998). Seasonal migration and diel vertical migration of the neon flying squid, Ommastrephes bartramii in the North Pacific, in: Okutani, T. Contributed papers to International Symposium on Large Pelagic Squids, July 18-19, 1996, for JAMARC's 25th anniversary of its foundation. pp. 13-30
In: Okutani, T. (1998). Contributed papers to International Symposium on Large Pelagic Squids, July 18-19, 1996, for JAMARC's 25th anniversary of its foundation. Japan Marine Fishery Resources Research Center: Tokyo. 269 pp., meer
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| Abstract |
In this paper, seasonal migration and diel vertical migration of the neon flying squid, Ommastrephes bartramii in the North Pacific was discussed, based on research vessel surveys, catch records of commercial drift net vessels, tagging experirnents, and results of tracking by biotelernetry. Distribution of this species was trans-Pacific at latitudes 35-50°N, with a seasonal shift northward in summer-fall, and southward in fall-winter, which were closely related to the oceanographic conditions. Seasonal migrations, spawning grounds and life span of two sub-populations (spring-breeding and fall-breeding groups) ofO. bartramii are discussed. A basic pattern in the diel vertical migration of O. bartramii was as foIlows: the squid swim at nighttime between the sea surface and the thermocline which is located near 40 m depth, then begin to descend around sunrise and remain at depths of 150-300 m during the daytime, and begin to ascend around sunset to reach the near surface swimming layer in nighttirne. The vertical migration corresponded weIl with the changing patterns of light intensities in the sea water. A hypothetical ecological strategy of this species over its life cycle in the North Pacific is proposed. |
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