Cobitis bilseli Battalgil, 1942

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 : 14

Cobitis bilseli Battalgil, 1942

( Fig. 7 )

Cobitis bilseli Battalgil, 1942: 292 , fig. 4 (type locality: Turkey: Lake Beyşehir).

Material examined. FSJF 1952 , 5 , 93–140 mm SL; Turkey: Konya prov.: stream Sarıöz at İsaköy about 9 km northeast of Beyşehir , 37.748 31.780 .— FSJF 2526 , 4 , 55–133 mm SL; Turkey: Konya prov.: stream Sarıçay 4 km north of Beyşehir , 37.715 31.708 .— FSJF 2624 , 3 , 130– 165 mm SL; Turkey: Konya prov.: outlet of Lake Beyşehir below dam in Beyşehir , 37.680 31.722 .

Material used in molecular genetic analysis. FSJF DNA-55 ; Turkey: Konya prov.: stream Sarıöz at İsaköy about 9 km northeast of Beyşehir , 37.748 31.780. (GenBank accession numbers: KJ 553049 , KJ552872 , KJ 553073 ) .

Diagnosis. Male Cobitis bilseli are distinguished from male C. battalgilae and all other Cobitis species known from the endorheic basins in Central Anatolia as well as from the Mediterranean Sea basin east of the Eşen River by having one lamina circularis on the pectoral fin (vs. two) and a short skin-flap before the genital papilla (vs. absent).

Distribution. Cobitis bilseli occurs in the Lake Beyşehir basin, where it inhabits the streams Sarıöz (Eylikler) and Sarıçay north of Beyşehir (and maybe others). Cobitis bilseli is seasonally found in the outlet of Lake Beyşehir below the dam in Beyşehir city, when the water flows over from the lake. It also occurs in the river flowing from Lake Beyşehir to Lake Suğla (Baran Yoğurtçuoğlu, pers. comm. 2017) and might be more widespread in the area.

Remarks. Cobitis bilseli is an unusual species, not only being the largest species of the genus, reaching 195 mm SL (Erk'akan et al. 1998). It has only one lamina circularis, despite which Bohlen et al. (2006), Geiger et al. (2014) and Perdices et al. (2016, 2018) found it to be related to the species of the C. simplicispina species group ( C. battalgilae , C. dorademiri , C. joergbohleni , C. phrygica , C. pirii , C. simplicispina , C. sipahilerae , C. turcica ) all having two laminae circularis. Erk'akan et al. (1998) pointed out that the first unbranched pectoral ray is thickened just where the other species have the second lamina circularis. In contrast to all other Cobitis species with one lamina circularis, its lamina circularis is strongly osseous, as in others of the C. simplicispina species group (vs. thin, scale-like) and in adult males there is a skin-flap before the genital papilla (vs. absent in other Cobitis ). Due to these characters, Erk'akan et al. (1998) placed C. bilseli in a separate subgenus: Beyshehiria . They suspected C. bilseli to be a relict lineage related to Siberian Cobitis species. Bohlen et al. (2006), however, rejected this hypothesis and it seems more likely that C. bilseli has evolved from an ancestor it shared with other Central Anatolian Cobitis . Based on DNA barcoding, Cobitis bilseli is well separated from all other included Cobitis , and by a minimum K2P distance of 2.5% to C. pirii , also supported as PTP entity.

Figures

FIGURE 7. Cobitis bilseli not preserved, about 190 mm SL; Turkey: Beyşehir canal.