Vol. 46 No. 4, 2007

Population Genetic Structure of the Year-Round Spawning Tropical Eel, Anguilla reinhardtii, in Australia

Kang-Ning Shen¹ and Wann-Nian Tzeng^2,3,*

¹Institute of Zoology, College of Life Science, National Taiwan University, Taipei 106, Taiwan
²Department of Life Science, College of Life Science, National Taiwan University, Taipei 106, Taiwan
³Institute of Fisheries Science, College of Life Science, National Taiwan University, Taipei 106, Taiwan

Kang Ning Shen and Wann Nian Tzeng (2007) The population genetic structure of tropical freshwater eels is less well investigated than that of their temperate counterparts.  To understand both the spatial and temporal population genetic structures of the year-round spawning tropical eel, Anguilla reinhardtii, variability at 6 microsatellite loci was examined in 799 glass eels.  Samples were collected from 5 estuaries across the range of the species in East Australia in 1997-1999.  F_ST, a measure of differentiation among populations, did not significantly differ among months or estuaries, suggesting that A. reinhardtii populations are panmictic.  An oceanic and prolonged spawning period, which lasts nearly the entire year, appears to facilitate interbreeding between adult eels from different generations and areas.  A short pelagic larval duration decreases larval dispersal, and therefore decreases the effect of latitude-correlated environmental variables on the spawning migration.  Mixing of individuals from different areas in ocean gyres may also contribute to genetic homogeneity among streams.

Key words: Tropical eel, Microsatellites, Panmixia, Spawning behavior.

*Correspondence: Tel: 886-2-33662887.  Fax: 886-2-23639570. E-mail:wnt@ccms.ntu.edu.tw