Map of Pearl River basin, Liujong River and Min River in southern China.

<p>Distribution areas of botiid species indicated as follows: Green: <i>S</i>. <i>pulchra</i>, violet: joint distribution area of <i>L</i>. <i>guilinensis</i> and ‘<i>B</i>.’ <i>zebra</i>, pink: new record of ‘<i>B</i>.’ <i>zebra</i>. Circles with numbers indicate geographical origin of analysed samples. Numbers correspond to locality numbers in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0159311#pone.0159311.t001" target="_blank">Table 1</a>.</p

Allozymes of <i>Leptobotia guilinensis</i>, <i>Sinibotia pulchra</i> and <i>’B</i>.<i>’ zebra</i>.

<p>Allozymes of <i>Leptobotia guilinensis</i>, <i>Sinibotia pulchra</i> and <i>’B</i>.<i>’ zebra</i>.</p

Morphometric comparison of <i>Leptobotia guilinensis</i>, <i>Sinibotia pulchra</i> and ‘<i>Botia</i>’ <i>zebra</i>.

<p>Morphometric comparison of <i>Leptobotia guilinensis</i>, <i>Sinibotia pulchra</i> and ‘<i>Botia</i>’ <i>zebra</i>.</p

Chromosme numbers and karyotype composition of <i>Leptobotia guilinensis</i>, <i>Sinibotia pulchra</i> and <i>’B</i>.<i>’ zebra</i>.

<p>Chromosme numbers and karyotype composition of <i>Leptobotia guilinensis</i>, <i>Sinibotia pulchra</i> and <i>’B</i>.<i>’ zebra</i>.</p

Phylogenetic relationships of Botiidae as revealed by the RAG-1 dataset.

<p>Phylogenetic relationships among freshwater fishes of the family Botiidae as revealed by a Bayesian analyses of the nuclear RAG-1 gene. The values at the nodes represent the Bayesian posterior probabilities. <i>Sinibotia zebra</i> and <i>Sinibotia pulchra</i> are sister species, while <i>Leptobotia guilinensis</i> is only distantly related.</p

Number of specimens and geographical origin of <i>Leptobotia guilinensis</i>, ‘<i>B</i>.’ <i>zebra</i> and <i>Sinibotia pulchra</i> analysed in the present study.

<p>Number of specimens and geographical origin of <i>Leptobotia guilinensis</i>, ‘<i>B</i>.’ <i>zebra</i> and <i>Sinibotia pulchra</i> analysed in the present study.</p

Mouthes of <i>Leptobotia guilinensis</i>, <i>Sinibotia pulchra</i> and <i>’B</i>.<i>’ zebra</i>.

<p>Mouth of a) <i>Sinibotia pulchra</i>, A 9102, 73.0 mm SL; b) ‘<i>B</i>.’ <i>zebra</i>, A 8904, 63.1 mm SL and c) <i>Leptobotia guilinensis</i>, A8868, 71.6 mm SL in ventral view. The presence of two prominent buttons on the lower lip (arrows in <i>S</i>. <i>pulchra</i>) are a diagnostic character of the genus <i>Sinibotia</i>. Scale bar is 1 mm.</p

Suborbital spines of <i>Leptobotia guilinensis</i>, <i>Sinibotia pulchra</i> and <i>’B</i>.<i>’ zebra</i>.

<p>Right suborbital spine of (a) <i>Sinibotia pulchra</i> (A1783, 70.5 mm SL), (b) ‘<i>Botia</i>’ <i>zebra</i> (A8607, 61.9 mm SL) and (c) <i>Leptobotia guilinensis</i> (A8573, 70.6 mm SL) in dorsal view. The spine bears a dorsal branch in <i>S</i>. <i>pulchra</i>, but this branch is missing in <i>L</i>. <i>guilinensis</i> and ‘<i>B</i>.’ <i>zebra</i>. A simple (= unbranched) suborbital spine is the diagnostic character for the genus <i>Leptobotia</i>. Scale bar is 1 mm.</p

Karyotypes of <i>Leptobotia guilinensis</i>, <i>Sinibotia pulchra</i> and <i>’B</i>.<i>’ zebra</i>.

<p>Karyotypes of the diploid species <i>Leptobotia guilinensis</i> (a) and the tetraploid species ‘<i>Botia</i>’ <i>zebra</i> (b) and <i>Sinibotia pulchra</i> (c). Bar = 10 μm.</p

Europe-wide distribution, reproductive pathways and contact zone in Odra R. basin of studied species.

<p>(a) Distribution area of <i>C. tanaitica</i> (blue circles), <i>C. taenia</i> (red area), and <i>C. elongatoides</i> (yellow area), with the directions of postglacial colonization of Europe by <i>C. taenia</i> (red arrows) and <i>C. elongatoides</i> (yellow arrow). Secondary contact zones are indicated by zigzag symbols, and the dispersal of clonal lineages is indicated by dotted arrows (modified from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045384#pone.0045384-Janko2" target="_blank">[13]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045384#pone.0045384-Culling1" target="_blank">[46]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045384#pone.0045384-Janko7" target="_blank">[64]</a>); (b) inferred reproductive pathways in <i>Cobitis</i> complex. Sperm at straight arrow indicates true fertilization, whereas sperm at round arrow indicates a triggering the egǵs development without paternal genetic contribution to the offspring; (c) Sampling sites in the Odra R. hybrid zone. For each locality, the presence of <i>C. taenia</i> and <i>C. elongatoides</i> is indicated by red and yellow dots, respectively and we indicate co-occurring hybrid biotypes, and their number in parentheses, if more than one. For each biotype on a given sample site, we list the presence of clones (MLL) and their absolute frequencies in parentheses, if more than one.</p