Variation in migratory history of Dolly Varden in a stream with an artificial dam in the Shiretoko Peninsula,Hokkaido, Japan |
| |
Authors: | Yoshiyuki Umatani Takaomi Arai Koji Maekawa |
| |
Institution: | (1) Field Science Center for Northern Biosphere, Hokkaido University, Sapporo Hokkaido, 060-0809, Japan;(2) International Coastal Research Center, Ocean Research Institute, The University of Tokyo, 2-106-1, Akahama, Otsuchi Iwate, 028-1102, Japan |
| |
Abstract: | The variation of migration patterns in Dolly Varden Salvelinus malma in a stream with an artificial dam (erosion-control-dam) in the Shiretoko Peninsula, Hokkaido Island, Japan, at the southernmost
part of its distribution, was examined by otolith Sr:Ca ratio analysis. All specimens from the above-dam area showed consistently
low Sr:Ca ratios (<5.0 × 10−3) throughout the otolith. In contrast, many specimens from the below-dam area had higher ratios (>5.0 × 10−3) throughout the otolith or only at the outer part than do those from the above-dam area. This higher ratio is probably due
to salinity effects. Specimen from the below-dam area could be divided into three types: (1) Consistently low Sr:Ca ratios
throughout the otolith, being freshwater residents. (2) Low Sr:Ca ratios around the inner part of the otolith, and thereafter
higher ratios toward the outer part, being typically anadromous. (3) Relatively higher Sr:Ca ratios throughout many or in
some parts of the otolith, indicating that these have migrated from the freshwater to brackish water or seawater from the
early life stage. These findings suggest that Dolly Varden has a high degree of plasticity in its migratory behavior. |
| |
Keywords: | Anadromy Dolly Varden Life history Migration Otolith Sr:Ca ratios |
本文献已被 SpringerLink 等数据库收录! |
|