Vol. 49 No. 3, 2010
Does Variable Habitat Usage by the Japanese Eel Lead to
Population Genetic Differentiation?
Han1,2,*, Yoshiyuki Iizuka3, and Wann-Nian Tzeng1,2
of Life Science, College of Life Science, National Taiwan University,
Taipei 106, Taiwan
2Institute of Fisheries Sciences, College of Life
Science, National Taiwan University, Taipei 106, Taiwan
3Institute of Earth Sciences, Academia Sinica,
Nangang, Taipei 115, Taiwan
Freshwater habitat use by Japanese eels (Anguilla japonica) is
facultative. However, the relationship between its habitat-use
strategy and the population genetic structure is still unknown.
To evaluate whether Japanese eel populations with different habitat-use
behaviors display genetic differentiation, we examined the otolith
Sr/Ca ratios by an electron probe microanalyzer of 166 wild Japanese
eels collected from the Kaoping River of southwestern Taiwan in
2006-2007. Eel habitat use was divided into 3 types according to
the mean and standard deviation (SD) of otolith Sr/Ca ratios: type 1
(fresh water, low-migratory, the SD of the Sr/Ca ratio < 1.4‰), type
2 (brackish water, low-migratory, the SD of the Sr/Ca ratio < 1.4‰),
and type 3 (highly migratory, the SD of the Sr/Ca ratio >
1.4‰). No significant genetic differentiation was found among
these 3 eel types (overall FST
= 0.0007, p = 0.99).
Our results suggest that the diverse habitat usage by Japanese eels is
due to behavioral plasticity that allows the utilization of different
ecological niches, rather than a heritable character that can cause
genetic differentiation among populations.
Key words: Japanese eel, Otolith Sr/Ca ratio,
Population genetic differentiation, Microsatellite DNA.
*Correspondence: Tel: 886-2-33663726.