Horizontal distribution and seasonal variability of the epipelagic chaetognath Sagitta elegans in relation to hydrography in the western subarctic Pacific Ocean
The spatial distribution and seasonal variability of epipelagic chaetognaths along the Kurile Islands and off south‐east Hokkaido, in the western subarctic Pacific Ocean. were investigated during the period from May 1990 to October 1992. Sagitta elegans was the dominant species among the epipelagic...
| Published in: | Fisheries Oceanography |
|---|---|
| Main Authors: | , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley
1995
|
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1111/j.1365-2419.1995.tb00069.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2419.1995.tb00069.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2419.1995.tb00069.x |
| Summary: | The spatial distribution and seasonal variability of epipelagic chaetognaths along the Kurile Islands and off south‐east Hokkaido, in the western subarctic Pacific Ocean. were investigated during the period from May 1990 to October 1992. Sagitta elegans was the dominant species among the epipelagic chaetognaths in the study area. Juvenile S. elegans were distributed mainly along the path of the mixed water which was determined by the acceleration potential anomaly (APA) at the iso‐pycnal density surface of 26.6 σθ. The location of the path of The mixed water meandered around cyclonic and anticyclonic eddies. Catches of S. elegans were made at temperatures ranging from 4.5 to 22.2d̀C. The juvenile distribution, however, was mostly restricted to between 1 and 4d̀C of the potential temperature determined at the isopycnal density surface of 26.6 σθ. Variability in the juvenile abundance within the path of the mixed water could be caused by predation rather than by food limitation because microzooplankton, which are known to he prey for juveniles, were abundant enough to meet the food requirements of juveniles in the study area. Adults occurred in spring (April‐May) and young individuals (juvenile and stage 1) were abundant in summer (June‐July), when a strong thermocline developed. The main spawning period appears to be during April‐May, with a possible second spawning period in the autumn. |
|---|