Cobitis fahireae

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 : 17-21

Cobitis fahireae Erk'akan, Atalay-Ekmekçi & Nalbant, 1998

( Fig. 11–13 )

Cobitis fahireae Erk'akan, Atalay-Ekmekçi & Nalbant, 1998: 10, fig. 2 (type locality: Turkey: Küçük Menderes, Selçuk- Aydin).

Cobitis vardarensis kurui Erk'akan, Atalay-Ekmekçi & Nalbant, 1998: 13, fig. 6 (type locality: Turkey: Menderes River, Selçuk-Aydin, Saplik Bridge).

Cobitis damlae Erkakan & Özmedir, 2014: 276 , fig. 1 (type locality: Turkey: Gölhisar prov.: Dalaman stream, 37.148 29.661). Material examined. FSJF 1975, 2, 46–62 mm SL; Turkey: İzmir prov.: Bakır River at Karadere about 2 km northeast of Kınık, 39.100 27.400.—FSJF 2294, 16, 42–76 mm SL; Turkey: İzmir prov.: stream Çiçekli, a tributary to stream Nif at Çiçekli, 38.505 27.272.—FSJF 2397, 11, 47–67 mm SL; Turkey: Balıkesir prov.: stream Madra about 3 km south of Altınova, 39.218 26.819.—HUIC uncat., paratypes, 2, 44– 45 mm SL; Turkey: İzmir prov.: stream Nif.—FSJF 3692, 4, 42–55 mm SL; Turkey: Burdur prov.: stream Bayındır 3 km west of Çavdır, 37.149 29.661.—FSJF 3703, 3, 33–57 mm SL; İzmir prov.: stream Develi 1 km south of Develi, 38.201 27.171.—HUIC uncat., holotype of C. kurui , 44.5 mm SL; paratype of C. kurui , 41 mm SL; Turkey: Aydın prov.: Menderes River, Saplık bridge.—FSJF 3709, 1, 62 mm SL; Turkey: Aydın prov.: Akçay River 10 km south of Nazilli, 37.810 28.315.—ZMH 4752, 6, 42–59 mm SL; Turkey: Golusar Gölü, SW Anatolia.

Material used in molecular genetic analysis. FSJF DNA-308; Turkey: Balıkesir prov.: stream Madra about 3 km south of Altınova, 39.218 26.819. (GenBank accession numbers: KJ553185 , KJ553276 ). — FSJF DNA-2815; Turkey: Burdur prov.: stream Bayındır 3 km west of Çavdır, 37.149 29.661. (BLOLD accession numbers: BOLD EUFWF2721- 18 to EUFWF2723-18).—FSJF DNA-2855; Turkey: İzmir prov.: stream Develi about 1 km south of Develi, 38.201 27.171. (BOLD accession numbers: BOLD EUFWF2736-18 to EUFWF2738-18).—FSJF DNA-266 Turkey: İzmir prov.: stream Çiçekli, a tributary to stream Nif at Çiçekli, 38.505 27.272. (BOLD accession number: EUFWF4326-18).

Diagnosis. Cobitis fahireae is distinguished from C. elongatoides , C. pontica and C. tanaitica by having a small or no black spot at the caudal-fin base (vs. roundish or ovoid, large, about size of pupil or eye) or if larger, then having one black spot at the upper and one black spot at the lower caudal-fin base (vs. always one spot only). It is distinguished from other Cobitis species in the eastern Aegean Sea basin by having one lamina circularis in the male (vs. two in C. dorademiri , C. phrygica and C. strumicae ).

Distribution. Cobitis fahireae occurs in the eastern Aegean Sea basin where it is found from the upper Dalaman River drainage (around Gölhisar) in the south to the Madra River drainage in the north.

Remarks. Erk'akan et al. (1998) described C. fahireae from "Küçük Menderes, Selçuk-Aydin" (= Küçük Menderes River at Selçuk in the Aydın province) and they described another species, C. vardarensis kurui , from the (Küçük) "Menderes River, Selçuk-Aydin, Saplik Bridge". Both species have been collected at the same day and probably from the same spot or close by. Despite several visits, we failed to find Cobitis in the remains of the Küçük Menderes River drainage. This might be related to the massive environmental changes in the area in the past 34 years. We examined one paratype of C. fahireae (from the Gediz River drainage) and the holotype and four paratypes of C. v. kurui from the type locality. Three paratypes of C. v. kurui are identified as C. afifeae (described below).

Erk'akan et al. (1998, 1999) report C. fahireae also from the lower Simav River (Marmara Sea basin; identified as C. taenia , see below) and from the Bakır and Gediz River drainages (Aegean Sea basin) and they report C. v. kurui from the Gediz and the Tahtalı (=Sasal) Rivers (all Aegean Sea basin). This suggests that both, C. fahireae and C. v. kurui should occur in sympatry in the Küçük Menderes and in the Gediz River drainages. We were not able to find more than one Cobitis species in the Gediz River drainage but Güçlü & Küçük (2015) report C. fahireae and C. kurui from the Gediz and distinguish both species by the colour of the spot at the upper caudal-fin base (black in C. fahireae vs. brown in C. kurui ).

Erk'akan et al. (1998) described Cobitis v. kurui as a subspecies of C. vardarensis and distinguished both subspecies by the brown, very small or absent spot at the upper caudal-fin base in C. v. kurui (vs. large and black in C. v. vardarensis ) and having more blotches along Z4 (no details given). Indeed, based on the description by Erk'akan et al. (1998) and the types examined, both subspecies can be immediately distinguished by the very small or absent upper caudal-fin base spot in C. v. kurui (vs. large in C. v. vardarensis ) and the pigmentation in Z3 formed by one line or a narrow band of brown spots (vs. many small, brown spots the in Z3 giving it a "sandy" pattern).

Despite Cobitis v. kurui having been described from the same place as C. fahireae , Erk'akan et al. (1998) do not compare C. kurui with C. fahireae directly, but state that C. kurui is almost identical to C. vardarensis . Erk'akan et al. (1998) distinguish C. fahireae from the " Cobitis vardarensis complex" by having a reduced pigmentation in Z3, the pigmentation in Z2 dotted and a rounded, small caudal spot. Indeed, in C. v. vardarensis there are many small, brown spots the in Z3 giving it a "sandy" pattern while in the types of C. fahireae and C. kurui , the pigmentation in Z3 is "reduced" as there is just one line or a narrow band of brown spots. Erk'akan et al. (1998) also state, that the pigmentation in Z2 is dotted in C. fahireae (vs. short stripes in C. v. kurui ). However, in our own materials (e.g. Fig. 9 ) there is a great variation in this character and all intermediate character states are observed. In addition, the spot at the upper caudal-fin base was found to be small and black or brown or absent in individuals of one population and no difference in the size and the shape of the spot could be found between the paratypes of C. fahireae and C. v. kurui , while the holotype of C. kurui has no black spot. We found all characters distinguishing C. fahireae and C. v. kurui to be highly variable even within populations. As we fail to distinguish C. v. kurui from C. fahireae , we have to treat both species as just one.

As C. fahireae and C. v. kurui were described in the same study, a First Reviser action is needed. The First Reviser action is the principle that in cases of conflicts between simultaneously published names, the first subsequent author can decide which name has precedence ( ICZN 1999: Article 24.2). Here we act as the First Revisers and give precedence to C. fahireae over C. v. kurui .

Cobitis damlae was described by Erk'akan & Özdemir (2014) based on one female individual from the stream Bayındır in the upper Dalaman River drainage. Erk'akan & Özdemir (2014) claim that C. damlae is a subterranean species but it has been collected from surface waters and not from an underground habitat. Erk'akan & Özdemir (2014) speculate that the sole individual was washed out from underground waters nearby. However, they provide no evidence for this speculation. Baran Yoğurtçuoğlu (Ankara) & JF visited the type locality of C. damlae in 2017 and found no spring or any subterranean waters adjacent to the type locality. The stream Bayındır flows down from a reservoir and we found no tributaries, which might originate from an underground source. Erk'akan & Özdemir (2014) mentioned the caves Keloğlan and Aslanini in the upper Dalaman River drainage about 30 km from the type locality of C. damlae , but no troglomorphic fish have ever been reported from these caves. It remains unclear how these caves or other subterranean habitats might be connected to the stream Bayındır.

The holotype and single known individual of Cobitis damlae ( Fig. 13 ) has no pigmentation and its eye is not reduced in size. Surprisingly, Erk'akan & Özdemir (2014) distinguished C. damlae by having vestigial eyes, a character state not seen from the picture. In subterranean fishes, the eye is usually reduced in size already in the very early phase of adaptation to an underground environment, while the pigmentation pattern is reduced later on, resulting in many subterranean fish with very small eyes but still having a colour patter ( Proudlove 2003). Furthermore, many subterranean fish with eyes become grey or brown, if exposed to light for some days (own observation). The situation is the opposite in C. damlae . Here the pigmentation is absent, but the eye is fully developed. On the picture ( Fig. 13 ), the eye-background is orange, suggesting, that the animal is albinotic. While it is impossible to exclude that the holotype of C. damlae originates from an underground habitat, there are strong indications that it is just an albinotic individual of a surface population.

Erk'akan & Özdemir (2014) identified the pigmented Cobitis from the stream Bayındır as C. battalgilae (see discussion above, identifying this population as C. phrygica ) but we found C. fahireae to be common in the stream Bayındır. Indeed, the absence of pigmentation and the fact that the holotype of C. damlae is a female makes it difficult to identify it as one of the two Cobitis species present in the area ( C. fahireae , C. phrygica ). Other characters given by Erk'akan & Özdemir (2014) do not allow distinguishing these two Cobitis species. Erk'akan & Özdemir (2014:278) distinguish C. damlae from C. battalgilae (= C. phrygica ) by having 6½ branched dorsal-fin rays (vs. 8) but the individual of C. phrygica shown by Erk'akan & Özdemir (2014: Fig. 2 [a drawing by T. Nalbant already published by Erk'akan et al. 1999: Fig. 8]) has 6½ branched dorsal-fin rays (indeed it has 6 branched dorsal-fin rays as T. Nalbant always ignored the ½ ray on his drawings) and all Cobitis examined for this study have 6½ or 7½ branched dorsal-fin rays. Erk'akan & Özdemir (2014:279) further distinguish C. damlae from C. battalgilae (= C. phrygica ) by having 8+8 branched caudal-fin rays (vs. 7+7) and 6½ branched pectoral-fin rays (vs. 7 – 8). A range of 7+7, 8+7 or 8+8 is common in populations of the Cobitis species examined for this study and C. fahireae caught by us at the type locality of C. damlae have 7+7 branched caudal-fin rays. No details are given how the pectoral-fin rays are counted. Erk'akan & Özdemir (2014) refer to Economidis et al. (1996) and Erk'akan et al. (1998) for methods of count. Neither Economidis et al. (1996) nor Erk'akan et al. (1998) count the pectoralfin rays as ½ and we can only suspect, that there are 7 branched pectoral-fin rays in the type of C. damlae (vs. 7 – 8 in C. battalgilae = C. phrygica ). In the C. fahireae from the type locality of C. damlae as well as in C. phrygica , 6– 10 branched pectoral-fin rays are very common and a range of 2–3 rays is typical in all species. The only indication given is the shape of the external part of the suborbital spine, which is simple in C. phrygica and bifurcate in C. fahireae . In the type of C. damlae , the spine is bifurcate (Erk'akan & Özdemir 2014). Furthermore, the type of C. damlae is a fully ripe female individual of only 64 mm SL. Females of C. phrygica grow much larger and reach up to 119 mm SL. As the type of C. damlae has a bifurcate suborbital spine, is relatively small and as we found only C. fahireae at the type locality, we are unable to distinguish C. damlae from C. fahireae . Our molecular data also place Cobitis from the type locality of C. damlae close to C. fahireae and we found no morphological character to distinguish these fishes from C. fahireae based on our materials examined and details given in the description by Erk'akan & Özdemir (2014). Therefore, we treat C. damlae as a synonym of C. fahireae .

Our molecular data suggest that there is substantial diversity within the species we call C. fahireae . We found a minimum COI K2P distance of 1.0% between Cobitis from the Dalaman / Gediz Rivers and the Şaşal River and 1.3% K2P distance between Cobitis from the Dalaman / Gediz Rivers and the Madra River. Cobitis from the Madra River are distinguished from those from the Şaşal River by 1.8%. Perdices et al. (2018) found very little molecular difference between Cobitis populations from the Gediz and Bakir Rivers. We found no differences between Cobitis populations from the Gediz and Dalaman Rivers. As the Küçük Menderes River is situated between the Gediz and the Dalaman Rivers, we could speculate, that this group is the one the type of C. fahireae was collected from. On the other hand, the Küçük Menderes River might have (had) an own fish fauna and its estuary is only 25 km southwest of the Şaşal River estuary. Both rivers are very likely to have flown together during the last glaciation. Therefore, it is likely that Cobitis from the Şaşal River are identical with C. fahireae from the Küçük Menderes River. More fieldwork is urgently needed, especially in the Küçük Menderes River, to locate C. fahireae there.

Our own molecular data ( Fig. 1 ) and Perdices et al. (2018) place Cobitis fahireae in the C. taenia species group ( C. avicennae , C. elongatoides , C. emrei , C. fahireae , C. faridpaki , C. pontica , C. puncticulata , C. satunini , C. saniae , C. splendens , C. tanaitica , C. taurica and C. vardarensis ). Based on DNA barcoding, C. fahireae is well separated from all other Cobitis included in this study and it is distinguished from its closest relative, C. tanaitica , by a minimum K2P distance of 4.5%, also supported as single PTP entity. It is further distinguished from C. elongatoides and C. pontica by having one line or a narrow band of brown spots in Z3 (vs. many small, brown spots the in Z3 giving it a "sandy" pattern). See below for details to distinguish C. fahireae from other species in the C. taenia species group in Anatolia ( C. puncticulata , C. splendens , C. taenia , C. satunini ) and from other Cobitis species found in the eastern Aegean Sea basin.

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 2. Site scale records of Cobitis species in the Middle East based on materials examined for this study and additional records listed in Table 10.

FIGURE 9. Cobitis elazigensis, FSJF 2559, male, 75 mm SL; Turkey: stream Eğri; FSJF 2495, female, 122 mm SL; Turkey: canal below Cipköy reservoir.

FIGURE 11. Cobitis fahireae, FSJF 1975, male, 46 mm SL; female, 62 mm SL; Turkey: Bakır River; FSJF 3703, female, 57 mm SL; Turkey: stream Develi; FSJF 3692, female, 51 mm SL, male 40 mm SL; Turkey: Büyük Menderes River.

FIGURE 12. Cobitis fahireae, HUIC uncat., holotype of C. kurui, 44.5 mm SL; Turkey: Küçük Menderes River.

FIGURE 13. Cobitis fahireae, from the top: HUIC, uncat., holotype of C. damlae, female, 64 mm SL; Turkey: stream Bayındır. Photo: Füsun Erk'akan; FSJF 3692, female, 55 mm SL; Turkey: stream Bayındır.