Hidden ancient diversification in the circumtropical lancelet Asymmetron lucayanum complex
Kon, T.; Nohara, M.; Nishida, M.; Sterrer, W.; Nishikawa, T. (2006). Hidden ancient diversification in the circumtropical lancelet Asymmetron lucayanum complex. Mar. Biol. (Berl.) 149(4): 875-883. http://dx.doi.org/10.1007/s00227-006-0271-y
In: Marine Biology: International Journal on Life in Oceans and Coastal Waters. Springer: Heidelberg; Berlin. ISSN 0025-3162; e-ISSN 1432-1793, more
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| Authors | | Top |
- Kon, T.
- Nohara, M.
- Nishida, M.
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- Sterrer, W.
- Nishikawa, T.
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| Abstract |
The tropical lancelet Asymmetron lucayanum (= Epigonichthys lucayanus) is distributed from the western Indian Ocean to the central Pacific Ocean, and the western Atlantic Ocean. Molecular phylogenetic analysis of mitochondrial cytochrome c oxidase subunit I (COI) sequences (1,035 bp) of A. lucayanum (80 specimens from seven localities) showed clearly that this species is genetically distinguished into three major groups of geographical populations based on neighbor-joining tree using maximum likelihood distance (HKY model with invariable sites and gamma correction), suggesting the existence of three cryptic species. Our genetic data show that (1) inter-oceanic divergence time between Clade B (the West-Central Pacific) and Clade C (the Atlantic) (d = 6.6%, ca. 12 million years ago) was smaller than intra-oceanic divergence time between Clade A (the Indo-West Pacific) and Clade B (d=39.5%, ca. 100 million years ago); (2) there are two cryptic species in the West Pacific in sympatry; and (3) high gene flow is implied between the Maldives and the Ryukyus in Clade A (10,000 km distance), the Philippines and Hawaii in Clade B (8,500 km distance), and Barbados and Bermuda in Clade C (2,200 km distance). |
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