English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Species composition and vertical distribution of oncaeid copepods, which are potentially important prey for juvenile fish, were investigated in the Kuroshio Extension region, the NW Pacific, in April, August, November 1998 and February 2001. Samples were collected from 8 discrete layers in the epipelagic zone (0-200 m depth) using MOCNESS (0.064 mm mesh) during both day and night. Thirty-five oncaeid species were identified. Oncaea (s.l.) zernovi and Spinoncaea ivlevi were numerically the dominant species comprising 20.0-48.2% and 15.2-26.8%, re- spectively, of adult oncaeid copepods in the epipelagic zone. Cluster analysis on all samples revealed that these were separated into three groups with discrete vertical ranges; the first one appearing in the 0-50 m depth surface layer in April and August and consisting mainly of Oncaea (s. str.), the second one located in the deepest layer and composed mostly ofO. zernovi and S. ivlevi with some mesopelagic species, and the third one located above the second one and having intermediate species composition. Species-specific vertical distributions indicate that most oncaeid popula- tions shifted downward from August to November, when the thermocline remarkably descended. However, most On- caea spp. did not show a downward shift with the thermocline, and were positively correlated to appendicularian abundances, suggesting that appendicularian houses, known to be oncaeid habitats and to provide food, were a possi- ble factor affecting their vertical distribution. Niche partitioning, allowing coexistence of congeners, might be ex- plained by differences in body size and distribution layers in Oncaea and by differences in distribution layer in Trico- nia.

Seasonal and diel changes in the vertical distribution of oncaeid copepods in the epipelagic zone of the Kuroshio Extension region