Stomach contents of Euphausia pacifica in Sanriku waters off northeastern Japan were examined bimonthly from April 1997 to February 1998 and compared to ambient microplankton abundance. Copepods were consumed by E. pacifica in proportion to their abundance in the water column in all sampling periods except April. Few copepods were consumed by E. pacifica in April despite their high abundance in the water column. Instead, in April the stomachs contained large numbers of diatoms. Copepods proved to be the most important food item, in terms of carbon, for most of the year in Sanriku waters. A tentative calculation of the impact of predation by E. pacifica on copepods in Sanriku waters showed that the daily impact accounted for 0.1-2.2% of copepod biomass. Since E. pacifica can suspension-feed on diatoms, dinoflagellates, tintinnids and invertebrate eggs, as well as raptorial-feed on small and slow-moving copepods, it appears to be capable of feeding on a wide variety of organisms by switching the feeding behavior according to ambient food conditions.
|Number of pages||10|
|Journal||Plankton Biology and Ecology|
|Publication status||Published - 2001 Jan 1|
- Euphausia pacifica
- Sanriku waters
ASJC Scopus subject areas
- Aquatic Science