open access

https://hdl.handle.net/2115/48558

Vertical segregation within four grazing copepods in the Oyashio region during early spring

英語

Neocalanus

2011-08

Oxford University Press

Journal of Plankton Research

33(8)

1230-1238

Fine-scale vertical distribution patterns of Neocalanus flemingeri, Neocalanus cristatus, Eucalanus bungii and Metridia pacifica were studied by stratified sampling (9 strata between 0 and 1000 m) with a vertical multiple plankton sampler (VMPS) every 3 h for 24 h during 21-22 March 2005 in the Oyashio region. Most C1-C5 stages of N. flemingeri and N. cristatus occurred in the 30-90 m and 70-200 m strata, respectively, both day and night. Irrespective of day and night, C3-C6 E. bungii were distributed broadly in the 200-430 m stratum (C5 inhabiting the shallowest layer). Thus, these three copepods exhibited vertical partitioning of their habitats in the upper layers. The C1-C6 of M. pacifica were distributed broadly from 140 to 400 m during daytime and migrated up to the 100-180 m layer at night (except for non-migrant C1 and C6 males). The within-species zonation of copepodid stages was less marked, but older stages tended to occupy deeper zones (N. flemingeri, N. cristatus and M. pacifica) or shallower zones (E. bungii). Gut content analyses of N. flemingeri and N. cristatus revealed the predominance of diatoms in both species, but the proportion of broken cells was greater in the deep-dwelling N. cristatus than in the shallow-dwelling N. flemingeri, suggesting the importance of sinking phytoplankton aggregates as food source for the former species.

学術雑誌論文

Accepted Manuscript

This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Journal of Plankton Research following peer review. The definitive publisher-authenticated version J. Plankton Res. (2011) 33 (8): 1230-1238 is available online at: http://plankt.oxfordjournals.org/content/33/8/1230

0142-7873