Cobitis taenia Linnaeus, 1758

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 : 36-37

Cobitis taenia Linnaeus, 1758

( Fig. 28 )

Cobitis taenia Linnaeus, 1758: 303 (type locality: Lake Mälaren, Sweden)

Cobitis spilura Holandre, 1837: 253 (type locality: Belgium: Liège / France: Moselle River, stream Nied below Malroy, Meuse River below Saint Mihiel)

Cobitis taenioides Băcescu & Maier, 1969: 52 [p. 39 of translation] (type locality: western Europe and Danube basin)

Material examined. FSJF 288 , 5 , 65–78 mm SL; Ukraine: Zhitomirskaya Region. Novgorod Volynsky district, Dnieper drainage, 50.789 27.393 .— FSJF 465 , 31 , 40–89 mm SL; Germany: River Oder at 3 km east of Schwedt , 53.059 14.308 .— FSJF 1946 , 5 , 54–70 mm SL; Turkey: Balıkesir prov.: stream Susurluk east of Susurluk , 39.917 28.165 .— FSJF 2006 , 1 , 68 mm SL; Turkey: Bursa prov.: Lake Ulubat at Gölyazı 40.159 28.674 .— FSJF 2280 , 11 , 45–67 mm SL; Turkey: Çanakkale prov.: stream Akçin between Ayvacık and Ezine at Bahçeli , 39.688 26.391 .— FSJF 2342 , 3 , 61–74 mm SL; Turkey: Çanakkale prov.: stream Tuzla about 1 km north of Assos , 39.498 26.333 .— FSJF 2387 , 17 , 57–78 mm SL; Turkey: Çanakkale prov.: stream Koca about 2 km west of Akçakoyun , 39.826 27.146 .— FSJF 2426 , 16 , 45–74 mm SL; Turkey: Çanakkale prov.: stream Menderes below Bayramiç dam, east of Bayramiç , 39.820 26.663 .— FSJF 3144 , 8 , 59–79 mm SL; Turkey: Zonguldak prov.: stream Devrek 6 km south of Devrek , 41.187 31.931 .— FSJF 3177 , 2 , 41–67 mm SL; Turkey: Zonguldak prov.: stream Yenice about 15 km west of Yenice , 41.232 32.204 .— FFR 5534 , 2 , 62–64 mm SL; Turkey: Çanakkale prov.: stream Kocaköy about 5 km east of Yenice , 39.941 27.310 .— FFR 0 5530, 9, 60–79 mm SL; Turkey: Balıkesir prov.: stream Sakar at Manyas Lake , 40.049 27.262 .— FFR 0 5546, 8, 54–62 mm SL; Turkey: Bursa prov.: stream Nilüfer at Nilüfer .— ZMH 2474 , 1 , 76 mm SL ; ZMH 4736 , 10 , 34–70 mm SL; Turkey: Lake İznik .

Material used in molecular genetic analysis. FSJF DNA-1630; Turkey: Zonguldak prov.: stream Yenice about 15 km west of Yenice, 41.232 32.204. (BOLD accession number: EUFWF2483-18).—FSJF DNA-1636; Turkey: Zonguldak prov.: stream Devrek about 6 km south of Devrek, 41.187 31.931. (BOLD accession number: EUFWF2481-18).—FSJF DNA-263; Turkey: Turkey: Çanakkale prov.: stream Tuzla about 1 km south of Ayvacık, 39.596 26.438. (BOLD accession number: EUFWF4325-18).—FSJF DNA-2910; Turkey: Çanakkale prov.: Karamenderes River at Karakul, 39.941 27.310. (GenBank accession number: MH795390 ).—FSJF DNA-2912; Turkey: Balıkesir prov.: stream Sakar flowing to Lake Manyas, 40.050 27.962. (GenBank accession number: MH795392 , MH795393 , MH795394 ).—FSJF DNA-2913; Turkey: Zonguldak prov.: stream Aydınlar, 41.268 31.541. (GenBank accession number: MH795403 , MH795404 ).—FSJF DNA-1191; Germany: Odra River at Reitwein (GenBank accession number: KM286530 )—ZFMK ICH-53777; Poland, Vistula drainage, 52.998 18.702. (BOLD accession number: EUFWF267-18).—ZFMK ICH-67470; Germany: Elbe drainage, 53.278 10.895. (BOLD accession number: EUFWF261-18).—ZFMK ICH-59248; Lithuania: Minija River, 55.936 21.625. (BOLD accession number: EUFWF263-18).—NRM51845; Sweden: Lake Vanern, 59.290 13.000. (GenBank accession number: KP 050512 ).—ZFMK ICH-53836; Latvia: Venta River, 56.989 22.075. (BOLD accession number: EUFWF265-18).—NRM52492; Sweden: Lake Yngaren, 58.817 16.645. (GenBank accession number: KJ128460 ).

Diagnosis. Cobitis taenia is distinguished from C. saniae , C. satunini and C. splendens by having a large focal zone in the sub-dorsal scales (about 1/2–1/3 of vertical scale diameter vs. focal zone small, about or less than 1/3 of the maximum scale diameter) and a small, comma-shaped or ovoid black spot at the upper caudal-fin base (vs. large, often roundish). Cobitis taenia is further distinguished from C. saniae by having the base of the lamina circularis narrowly connected to the pectoral-fin ray (vs. widely connected). It is further distinguished from C. splendens by the pigmentation in Z3 reaching from the pectoral-fin base and the caudal peduncle in the male (vs. pigmentation much reduced, not reaching the vertical of the dorsal-fin origin) and blotches in Z4 anterior to the dorsal-fin origin being horizontally elongate, often very densely set and fused into short or longer stripes (vs. vertically elongate, not fused to each other fused).

Cobitis taenia is distinguished from C. puncticulata from the Marmara Sea basin by having well separated and large blotches in Z2 and Z4 (vs. very small, indistinct or confluent), un-pigmented flank below Z4 (vs. pigmented) and a pale yellowish or whitish background coloration (vs. brownish). Cobiti s taenia is distinguished from C. simplicispina by having one laminae circularis in the males (vs. two).

Distribution. In Asia, C. taenia is known from the Yenice and Bartın River drainages in the south-western Black Sea basin. It is also distributed in the southern Marmara Sea basin from the Tuzla River east to Lake İznik basin including the Simav River drainage. Cobitis taenia is widespread in Central and Eastern Europe.

Remarks. Cobitis taenia is widespread in Eastern and Central Europe including the northern Black Sea basin, where it is found from the Dniester River east to the Dnieper ( Kottelat & Freyhof 2007). Similar looking Cobitis in the eastern Black Sea basin have been identified as C. satunini and those from the adjacent northern Anatolia and the southern Marmara Sea basin had been identified as C. splendens , C. fahireae and C. kurui by Erk'akan et al. (1999). Cobitis taenia is the only species of Cobitis in the Black Sea basin having a large focal zone in the subdorsal scales and a small black spot at the upper caudal-fin base. These two characters are the only external characters distinguishing C. taenia from C. satunini . Cobitis taenia is also unique among all Cobitis species studied in the Black Sea basin for having 48 chromosomes (vs. 50 in C. elongatoides , C. pontica , C. taurica , and C. tanaitica ) ( Janko et al. 2005, Vasil'eva & Vasil'ev 2006). The chromosome numbers have not been studied in C. satunini or in the populations identified here as C. taenia from the northern Black Sea basin and the southern Marmara Sea basin.

Our DNA barcode data separate the Anatolian C. taenia from European C. taenia (minimum KP2 distance 1.6%) as well as from C. satunini (minimum KP2 distance 1.6%). The RAG1 molecular data presented by Perdices et al. (2018) does not support the Anatolian C. taenia (considered as Cobitis sp. Marmara-Black Sea), European C. taenia (only partially supported) and C. satunini as monophyletic species (although they were supported in cyt b phylogenies). Also both PTP approaches applied by us suggest Anatolian C. taenia , European C. taenia and C. satunini to represent one unit. But by far not enough populations and individuals have been studied for their molecular characters in Anatolia and for the time being, we keep accepting C. satunini as a valid species, but identify western Anatolian populations as C. taenia , as we see no strong enough support to describe them as a new species. It is beyond the possibilities of this study to resolve the case as we could not apply karyological methods. Chromosome studies of Anatolian C. taenia and C. satunini are urgently needed, to decide, if one, two or three species are involved. Externally, we are able to distinguish C. satunini from C. taenia , but we found no consistent character to distinguish Anatolian C. taenia from European C. taenia . To complicate the situation further, there are Cobitis populations in Anatolia, which cannot be distinguished from C. taenia except that some individuals have a small focal zone in the scales while others have a large or intermediate focal zone. These loaches have been found in the Tuzla River, which flows into the norther most Aegean Sea basin as well as in the Simav River drainage, which flows to the southern Marmara Sea basin. We identify these as C. taenia as suggested by their DNA barcode haplotypes. Indeed, these Cobitis have been found within the distribution range of those identified as C. taenia in the Marmara Sea basin and we suspect that all belong to one species, in which the focal zone of the subdorsal scales is variable.

Figures

FIGURE 28. Cobitis taenia, from the top: not preserved, male, about 50 mm SL; Turkey: stream Tuzla, same data as FSJF 2342; not preserved, female, about 70 mm SL; Turkey: stream Koca, same data as FSJF 2387; FSJF 3144, male, 65 mm SL; Turkey: stream Devrek.