裂腹魚屬為特產(chǎn)于亞洲高原地區(qū)的一類鯉科魚類。所謂“裂腹魚”因其腹部肛門和臀鰭兩側(cè)各有一排較大的排列整齊的鱗片（臀鱗），兩排鱗片之間有一條明顯的裂縫,，初看起來象是肚子裂開一樣,，故名裂腹魚。裂腹魚類是青藏高原及其周邊地區(qū)的特有魚類，它們是隨著青藏高原的形成而出現(xiàn)的,，裂腹魚的演化過程與青藏高原的形成和發(fā)展息息相關(guān)。云貴高原的廣大地區(qū),，地質(zhì)條件復(fù)雜,，河流眾多，為青藏高原自西向東南的傾斜延伸面,，正是由于這樣的傾斜控制了金沙江,、怒江、瀾滄江等河流的流向,。青藏高原強(qiáng)烈隆起及其相伴的差異運(yùn)動,，直接影響了云貴高原水系格局的形成、河流襲奪,。
為了更清楚地闡明裂腹魚屬魚類在云貴高原地區(qū)的歷史生物地理學(xué)過程,，中國科學(xué)院昆明動物研究所楊劍博士在導(dǎo)師楊君興研究員和陳小勇副研究員的指導(dǎo)下，重點(diǎn)加強(qiáng)了云南貴高原地區(qū)該屬魚樣本的收集,，構(gòu)建了這一地區(qū)較為完整的裂腹魚屬魚類的系統(tǒng)進(jìn)化樹,。研究結(jié)果表明：系統(tǒng)樹不支持裂腹魚屬魚類亞屬的劃分；不同種類Cyt b 基因序列的最大遺傳距離為11.2%,；怒江和瀾滄江的個(gè)體以較高的支持率聚成一單系,；伊洛瓦底江水系與雅魯藏布江的個(gè)體以較高的支持率聚成一單系；識別了一新地理單元群體——泛金沙江群體(金沙江,、元江,、南盤江、北盤江),；系統(tǒng)樹不支持長江第一灣為襲奪灣的觀點(diǎn),，古金沙江入古紅河可能不經(jīng)劍川-洱海一線；起源于3.6Ma 的青藏運(yùn)動是橫斷山區(qū)各大水系發(fā)育的主要力量,，也是該地區(qū)裂腹魚屬魚類成種的主要時(shí)期,。(生物谷Bioon.com)
DOI: 10.1111/j.1439-0469.2012.00661.x
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A re-examination of the molecular phylogeny and biogeography of the genusSchizothorax (Teleostei: Cyprinidae) through enhanced sampling, with emphasis on the species in the Yunnan–Guizhou Plateau, China
Jian Yang1,2, Jun Xing Yang1, Xiao Yong Chen1
The mitochondrial DNA cytochrome b sequences of 36 Schizothorax species from 51 localities in the Yunnan–Guizhou Plateau (YGP) and its adjacent areas were analysed. Maximum parsimony, Maximum likelihood and Bayesian phylogenetic analyses were performed to examine the relationships of Schizothorax species. A hypothesis of the phylogenetic relationships of the species is given. A relaxed molecular clock based on Bayesian evolutionary analysis was used to tentatively calculate the divergence times of Schizothorax. Samples from the YGP were tentatively grouped into three geographically distributed clades: the Tsangpo-Irrawaddy, the Mekong-Salween and the Trans-Jinsha River (including Jinsha, Red, Nanpan and Beipan Rivers). Calibration of the molecular clock revealed that two geological periods, the late Miocene about 10 million years before present (Myr BP) and the Pliocene (4.0 Myr BP), were important times in the vicariant speciation ofSchizothorax. The phylogenetic history of the species is congruent with events caused by the uplift of the Tibetan Plateau and the YGP. The divergence ofSchizothorax species in YGP began in the Pliocene. Our phylogenetic trees did not support the hypothesis that the paleo Jinsha River was drained through the Yangtze River-Jianchuan Lake-Erhai Lake to the Red River. Schizothorax in the Beipan River were derived from the Jinsha River.
