Taxonomic and Molecular Phylogenetic Studies of Stomiiforms from Taiwan
Date Issued
2007
Date
2007
Author(s)
Liao, Yun-Chih
DOI
zh-TW
Abstract
Stomiiforms are mesopelagic and bathypelagic fishes. The purposes of this study include expading taxonomic studies of Stomiiformes around Taiwanese waters and inferring phylogenetic relationships among this group of fishes based on mitochondrial Cyt b and CO1 gene sequences.A total of 56 species in 34 genera and 5 families have been recorded based on the classification system of Nelson (2006). Among them, there is one new species and 25 newly recorded species. They are: Astronesthes formosana n. sp. ; Cyclothone atraria, C. pallida, Diplophos orientalis, Gonostoma atlanticum, Ichthyococcus elongatus, Pollichthys mauli, Polymetme elongate, Vinciguerria nimbaria, Astronesthes indica, A. indopacifica, A. splendida, Bathophilus kingi, B. nigerrimus, Borostomias elucens, Chauliodus macouni, Echiostoma barbatum, Eupogonesthes xenicus, Eustomias bifilis, Heterophotus ophistoma, Leptostomias multifilis, Malacosteus niger, Melanostomias valdiviae, Pachystomias microdon, Photostomias guernei, Rhadinesthes decimus, and Thysanactis dentex. Five species in 3 genera i.e. Diplophos pacificus, Polyipnus spinosus, P. tridentifer, P. unispinus, and Eustomias longibarba, that have been reported in early literatures were not included herein due to lack of specimens. Synonyms, specimen, diagnostic characters, color photographs or line-drawings, distributions, depth, and a key to species of Taiwan are given.
The phylogenetic relationships within Stomiiformes were studied using the mitochondrial Cyt b and CO1 genes, and the Phylogenetic inference method including naximum parsimony, maximum likelihoos, and Bayesian methods. The results indicate that Stomiiformes is a monophyletic group, and Stomiidae could also be monophyly. The phylogenetic relationships constructed by different methods were incongruent with those by morphological characters. For example, the monophyly of families Diplophidae, Gonostomatidae, Sternoptychidae, and Phosichthyidae were not supported. Besides, Diplophos is a basal taxa to other Stomiiformes and Triplophos are clustered with Gonostomatidae rather than with Phosichthyidae. The special molecular characteristics such as longer branch length and short interior branch length from tree topologies, high proportion of variable sites, and saturation for base substitutions may obscure the phylogenetic relationships of Stomiiformes and result in lower bootstrap supporting value. The evidences from fossil records and the molecular tree of Stomiformes suggest that these deep-sea fishes had a very long evolutionary history (56-15 million years ago) and they might pass through species radiation shortly in stable deep-sea environment.
Subjects
巨口魚目
分類
分子類緣關係
粒線體去氧核糖核酸
Cyt b
CO1
Stomiiformes
taxonomy
molecular phylogeny
mitochondrial DNA
Taiwan
Type
thesis