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Vol. 48 No. 6, 2009
A New Anguilla
Species and a Reanalysis of the Phylogeny of Freshwater Eels
Hui-Yu
Teng1, Yeong-Shin Lin2, and Chyng-Shyan Tzeng1,3,*
1Department
of Life Science, National Tsing Hua University, Hsinchu 300, Taiwan
Institute of Bioinformatics and Systems Biology, National Chiao Tung
University, Hsinchu 300, Taiwan
3Institute of Bioinformatics and Structural Biology,
National Tsing Hua University, Hsinchu 300, Taiwan
Hui-Yu
Teng, Yeong-Shin Lin, and Chyng-Shyan Tzeng (2009) Evidence of a
new species of Anguillid eel, Anguilla
huangi
sp. nov., was obtained from examining eel specimens collected from the
Cagayan River estuary, northern Luzon I., the Philippines. Both
glass eels and cultured eels reared in Taiwan for 5 yr were
examined. The morphological measurements of A. huangi sp. nov. overlap with
those of A. celebesensis Kaup, 1856 and A. interioris
Whitley, 1938, so that this new species cannot be distinguished using
morphological characteristics alone. We sequenced its complete
mitochondrial genome and constructed a phylogeny of all currently
recognized freshwater eel species and subspecies based on both
molecular and morphological data. Although A. huangi sp. nov. seemed to be
morphologically more similar to A.
celebesensis, the
molecular phylogeny showed a strongly supported clustering of A. huangi sp. nov. and A. interioris. The genetic
distance between A. huangi
sp. nov. and A. interioris was
similar to that between A. anguilla
(Linnaeus, 1758) and A. rostrata (Le
Sueur, 1817). The distinct molecular phylogeny ensures the
specific status of this new freshwater eel. On the other hand,
based on the likelihood analyses, the phylogeny of freshwater eels
seems to be better represented by polytomies. These polytomies
are likely derived from multiple radiation (rapid speciation)
events. We further inferred that each radiation event may also
have included a large-scale expansion in distribution. The
morphological phylogenetic tree generated using the minimum network
(MinNet) method was generally consistent with the molecular
phylogeny. We also propose a possible evolutionary history for
freshwater eels. The Central American Isthmus hypothesis for the
dispersal route of the Atlantic eels was supported by various lines of
evidence.
Key words: New
species, Anguilla huangi, The
Philippines, Morphology, Mitochondrial genome.
*Correspondence: Tel: 886-3-5742765. Fax:
886-3-5742765. E-mail:labtcs@gmail.com
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