Cobitis linea (Heckel, 1848)

Freyhof, Jörg, Bayçelebi, Esra & Geiger, Matthias, 2018, Review of the genus Cobitis in the Middle East, with the description of eight new species (Teleostei: Cobitidae), Zootaxa 4535 (1), pp. 1-75 : 24-25

Cobitis linea (Heckel, 1848)

( Fig. 18 )

Acanthopsis linea Heckel, 1848: 267 (type locality: Iran: creeks around Persepolis [Marvdasht Plain, about 70 km northeast of Shiraz]).

Material examined. FSJF 2240 , 15 , 38–100 mm SL; Iran: Fars prov.: River Kor about 10 km south of Dashtak , 30.193 52.465 .— FSJF 3219 , 8 , 32–39 mm SL; Iran: Shiraz prov.: Malous spring 10 km north of Shiraz , 29.877 52.481 .

Material used in molecular genetic analysis. FSJF DNA-1982 , Iran: Shiraz prov. : Malous spring 10 km north of Shiraz, 29.877 52.482. (GenBank accession numbers: KP 050530 , KP 050539 ) .

Diagnosis. Cobitis linea is distinguished from C. avicennae and C. kellei , two other species from the Persian Gulf basin, by having two laminae circularis in the male (vs. one). It is distinguished from C. elazigensis , the only other Cobitis species in the Persian Gulf basin having two laminae circularis, by the lack of an axillary pelvic lobe (vs. present) and the blotches in Z4 very small and roundish or comma-shaped along its whole length, densely set, often fused to short stripes or dissociated into an open field of several rows of small spots and blotches (vs. blotches in Z4 irregularly squarish, between vertical of pectoral-fin origin and dorsal-fin base, roundish and usually widely spaced posterior to the dorsal-fin base, not fused into stripes).

Cobitis linea is distinguished from C. evreni and C. levantina by the blotches in Z4 very small and roundish or comma-shaped along the flank, densely set, often fused to short stripes or dissociated into a field of several rows of blotches (vs. blotches horizontally elongate or squarish anterior to the dorsal-fin origin, fused into a stripe in some C. levantina , Z4 is formed by a dark-brown stripe reaching from above the pectoral-fin base until the anus or beyond in C. evreni ). Cobitis linea is further distinguished from C. evreni by the presence of the black spot at the uppermost caudal-fin base (vs. absent) and from C. levantina by the maxillary barbel reaching the vertical of the front margin or the middle of the eye (vs. not reaching).

Distribution. Cobitis linea is endemic to the Kor River drainage, an endorheic basin in Central Iran.

Remarks. Molecular data ( Fig. 1 ) place Cobitis linea in a species group with C. aliyeae , C. anabelae , C. elazigensis , C. erkakanae , and C. levantina . Based on DNA barcoding it is well separated from all other included Cobitis and by a minimum K2P distance of 4.7% to C. elazigensis , also supported as PTP entity.

See below for details to distinguish C. linea from other species in the C. linea species group.

Figures

FIGURE 1. Maximum likelihood estimation of the phylogenetic relationships based on the mitochondrial COI barcode region (TN93 model, discrete Gamma distribution for rate differences with 3 categories +G parameter = 0.3792. Nucleotide positions with less than 95% site coverage were eliminated, resulting in 590 analysed positions. Numbers of major nodes indicate bootstrap values from 1000 pseudoreplicates from the ML, NJ and MP method. A star denotes highest possible support from all three methods. Solid bars right to the specimen labels indicate species delimitation results from PTP followed by the results of the mPTP approach as dashed bars. Except to the outgroups and the branch to the right part of the figure, the tree is drawn to scale with branch lengths depicting number of substitutions per site.

FIGURE 18. Cobitis linea, FSJF 2240, female, 89 mm SL; Iran: Kor River.