title: Phylogenetic relationships of Acheilognathidae (Cypriniformes: Cyprinoidea) as revealed from evidence of both nuclear and mitochondrial gene sequence variation: evidence for necessary taxonomic revision in the family and the identification of cryptic species.
abstract: Bitterlings are relatively small cypriniform species and extremely interesting evolutionarily due to their unusual reproductive behaviors and their coevolutionary relationships with freshwater mussels. As a group, they have attracted a great deal of attention in biological studies. Understanding the origin and evolution of their mating system demands a well-corroborated hypothesis of their evolutionary relationships. In this study, we provide the most comprehensive phylogenetic reconstruction of species relationships of the group based on partitioned maximum likelihood and Bayesian methods using DNA sequence variation of nuclear and mitochondrial genes on 41 species, several subspecies and three undescribed species. Our findings support the monophyly of the Acheilognathidae. Two of the three currently recognized genera are not monophyletic and the family can be subdivided into six clades. These clades are further regarded as genera based on both their phylogenetic relationships and a reappraisal of morphological characters. We present a revised classification for the Acheilognathidae with five genera/lineages: Rhodeus, Acheilognathus (new constitution), Tanakia (new constitution), Paratanakia gen. nov., and Pseudorhodeus gen. nov. and an unnamed clade containing five species currently referred to as "Acheilognathus". Gene trees of several bitterling species indicate that the taxa are not monophyletic. This result highlights a potentially dramatic underestimation of species diversity in this family. Using our new phylogenetic framework, we discuss the evolution of the Acheilognathidae relative to classification, taxonomy and biogeography.
authors.affiliation: Biodiversity Research Center, Academia Sinica, Taipei 11529, Taiwan; Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan; Department of Biology, Saint Louis University, St. Louis, MO 63103, USA.
authors.forename: Chia-Hao
authors.initials: CH
authors.lastname: Chang
authors.affiliation: Department of Oceanography, National Sun Yet-sen University, Kaohsiung 80424, Taiwan; Institute of Biodiversity Science, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Li
authors.affiliation: Biodiversity Research Center, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Kwang-Tsao
authors.initials: KT
authors.lastname: Shao
authors.affiliation: Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan; Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu 30068, Taiwan.
authors.forename: Yeong-Shin
authors.initials: YS
authors.lastname: Lin
authors.affiliation: Japan Wildlife Research Center, Tokyo 130-8606, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Morosawa
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul 151-747, Republic of Korea.
authors.forename: Sungmin
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Biological Science, Sangji University, Wonju 220-702, Republic of Korea.
authors.forename: Hyeyoung
authors.initials: H
authors.lastname: Koo
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul 151-747, Republic of Korea.
authors.forename: Won
authors.initials: W
authors.lastname: Kim
authors.affiliation: Department of Biological Sciences, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Jae-Seong
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Shunping
authors.initials: S
authors.lastname: He
authors.affiliation: School of Biology, University of St Andrews, St Andrews, Fife KY16 8LB, UK; Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Květná 8, 603 65 Brno, Czech Republic.
authors.forename: Carl
authors.initials: C
authors.lastname: Smith
authors.affiliation: Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Květná 8, 603 65 Brno, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Reichard
authors.affiliation: Natural History Museum & Institute, Chiba 260-8682, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Miya
authors.affiliation: Natural History Museum & Institute, Chiba 260-8682, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sado
authors.affiliation: Aquatic Life Conservation Research Center, Research Institute of Environment, Agriculture and Fisheries, Osaka 572-0088, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Uehara
authors.affiliation: Institute of Oceanography, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Lavoué
authors.affiliation: Institute of Oceanography, National Taiwan University, Taipei 10617, Taiwan. Electronic address: wjchen.actinops@gmail.com.
authors.forename: Wei-Jen
authors.initials: WJ
authors.lastname: Chen
authors.affiliation: Department of Biology, Saint Louis University, St. Louis, MO 63103, USA.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Mayden
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D005075:Biological Evolution; D003530:Cyprinidae / Q000145:classification* / Q000235:genetics; D050259:Genes, Mitochondrial; D014644:Genetic Variation; D016013:Likelihood Functions; D010802:Phylogeny; D017422:Sequence Analysis, DNA
keywords: Acheilognathinae; Cryptic species; Cyprinidae; Cytochrome b; European bitterling; Nuclear loci