コイ科の希少種ウケクチウグイの耳石Sr:Ca比解析による河川型生活史の検証

Otolith Sr : Ca ratios of an endangered cyprinid Tribolodon nakamurai indicating absence of sea-migrating traits

Creators Imai Chifumi

Creators Sakai Harumi

Creators Arai Takaomi

The strontium : calcium concentration ratios in the otoliths of ten variously-sized Tribolodon nakamurai (Cyprinidae) individuals collected from the lower reaches of the Mogami River were examined and compared with those of six spawning individuals from the upper reaches of the river in order to establish the existence or otherwise of any sea-migrating traits. The ratios were relatively stable from the core to the edge of the otolith in all specimens, indicating a solely freshwater life style. Any conservation program for T. nakamurai should therefore be based on the premise that the species has a fluvial mode of life.

[ISSN]0370-9361