open access

https://hdl.handle.net/2115/38425

Spatial distribution patterns and nutritional status of kichiji rockfish Sebastolobus macrochir in summer on the continental slope off the Pacific coast of Hokkaido, Japan

日本語

陸棚斜面

2006-05-15

The Japanese Society of Scientific Fisheries

Bulletin of the Japanese Society of Scientific Fisheries

72(3)

430-439

The spatial distribution patterns and nutritional status of the kichiji rockfish Sebastolobus macrochir were investigated off the Pacific coast of Hokkaido during the summer of 2001-2004. Fish≤100mm SL were chiefly distributed at depths of 550-750m off the southeastern area of Cape Erimo where their principal prey, gammarid amphipods, were abundant. The 101-150mm SL fish were concentrated in shallow areas where their principal prey, the decapod Neocrangon communis, was abundant. Conversely, fish≥151mm SL were observed to utilize various prey items and were widely distributed in the study area, suggesting a foraging strategy to reduce the intra- and inter-specific competition for food and to obtain food efficiently. The condition factor and hepatosomatic index of S. macrochir tended to decrease with increased depth. Given that the principal prey of S. macrochir ranged from decapods (high energy content) to ophiuroids (low energy content) with increased depth, the variation in the nutritional status of fish could be related to differences in the energy content of their prey. Despite feeding on prey items with a relatively high energy content, the nutritional status of 101-150mm SL fish was low. This is probably due to the fact that the fish in this size class grow rapidly.

学術雑誌論文

Version of Record

© 2006 The Japanese Society of Fisheries Science

0021-5392

AN00193422