Alburnus kotschyi Steindachner, 1863

Freyhof, Jörg, Özuluğ, Müfit, Kaya, Cüneyt, Bayçelebi, Esra & Turan, Davut, 2018, Redescription of Alburnus kotschyi Steindachner, 1863, with comments on Alburnus sellal adanensis Battalgazi, 1944 (Teleostei: Leuciscidae), Zootaxa 4382 (3), pp. 573-582 : 574-575

Neotype designation of Alburnus kotschyi Steindachner, 1863

As two species of Leuciscidae ( Alburnus , Pseudophoxinus ) occur at Arsuz, Steindachner’s description might allow the identification of the species he had in hand. Steindachner (1863) mentions 16 branched pectoral-fin rays in A. kotschyi (vs. 15–17 in Alburnus from Arsuz; 13–14 in Pseudophoxinus from Arsuz), 6 branched pelvic-fin rays (vs. 8; 7), 7½ branched anal-fin rays (vs. 9½–11½; 7½), 8½–9½ branched dorsal-fin rays (vs. 8½; 7½), 48 (total?) scales along the lateral line (vs. 49–59; 41–44), head shorter than greatest body depth (vs. longer; equal or shorter), head length about five times in total length (vs. 4.8–5.2; 4.5–4.7), head depth about 66% of head length (vs. head length 67–75%; 71–77 of head depth at nape), eye diameter 3.5 times in head length (vs. 3.3–4.0, 3.1–3.7), eye diameter less than snout length (vs. smaller; equal), eye diameter greater than interorbital distance (vs. smaller in both species), eye diameter 1.3 times in postorbital distance (vs. 1.5–1.8 in both species), posterior end of the upper jaw reach vertical of anterior eye margin (vs. slightly in front of vertical in both species), nares situated anteriorly to corner of mouth (vs. anterior in both species), dorsal profile slightly increasing from occiput to dorsal-fin origin (vs. slightly increasing in both species), head profile strongly decreasing from forehead to tip of snout (vs. slightly deceasing in both species), caudal peduncle depth 2.5 times in head length (vs. 2.2–2.7; 1.9–2.1); dorsal-fin origin behind vertical of pectoral-fin tip (vs. behind in both species), predorsal length about one eye diameter longer than postdorsal length (vs. predorsal length 120–140% of the sum of postdorsal length and eye diameter; 128–135%), dorsal-fin base about equal to postorbital length (vs. about equal in both species), dorsal-fin height slightly shorter than pectoral-fin length (vs. almost equal; longer), dorsal-fin height about 66% of head length (vs. 77–90%; 78– 97%), longest anal-fin ray slightly shorter than longest dorsal-fin ray (vs. shorter in both species), caudal fin deeply forked (vs. deeply forked in both species), lower caudal-fin lobe longer than head length (vs. equal; longer), largest scales slightly larger than 50% of eye diameter (vs. 57–67%; 47–60%, measured as height of lateral line scale below dorsal fin origin) and a prominent black lateral stripe (vs. present in both species). Steindachner (1863) did not mention how he counted the last two branched rays articulating with a single pterygiophore in the anal and dorsal fins. By comparison with his text for species for which the number of branched dorsal-fin rays is not variable (7 [7½] in Iberocypris alburnoides, 7 [7½] in Anaecypris hispanica , 7 [7½] in Iberochondrostoma lemmingii ( Steindachner 1866) , we deduce that he counted the last two rays as a single ray.

While the Pseudophoxinus from Arsuz agrees with the description of A. kotschyi by having 7½ branched analfin rays and some of the characters mentioned above, it is also distinct by having, among other characters, 7½ branched dorsal-fin rays (vs. 8½–9½), and 41–44 total lateral-line scales (vs. 48). The Alburnus found in Arsuz agrees with Steindachner’s description by having 8½ branched dorsal-fin rays, being superficially very similar to A. arborella but it differs from the description by having 51–58 total lateral-line scales (vs. 48, 49– 59 in populations from Seyhan and Ceyhan), 9½–10½ branched anal-fin rays (vs. 7½) and some characters mentioned above. We exclude the possibility that Steindachner (1863) had seen hybrids between the Alburnus and Pseudophoxinus , as such hybrids should be intermediate between parents at least in meristic characters, and this is not the case in the characters given in the description by Steindachner. We cannot exclude the possibility that an additional species was present in Arsuz in Steindachner’s time, which is now extinct, extirpated or could simply not be collected by us. The fact, that Steindachner (1863) stated that the fishes are of 50–100 mm (most likely) total length makes clear that he had more than one individual in hand. We could also not exclude that Steindachner (1863) had mixed the Pseudophoxinus and the Alburnus from Arsuz in his description. However, no variations are given in the description, which suggests it was based on a single individual only. No other leuciscid known from adjacent areas fully agrees with Steindachner’s description, so only an extinct species or a species not yet discovered could be taken into consideration.

Therefore, we find here clearly the situation where a name cannot be connected to a species without uncertainties. To eliminate these uncertainties concerning the application of the name A. kotschyi and potential confusion with any known species we designate here one individual of Alburnus collected from Arsuz (IUSHM 37900-253, Fig. 1 ) as neotype of A. kotschyi . This species is superficially similar to A. arborella and has the distinguishing character states of A. kotschyi sensu Steindacher , viz. 8½ branched dorsal fin rays, a prominent lateral stripe, head length 5 times in total length and predorsal length about one eye diameter longer than postdorsal length (see others above). As the name A. kotschyi has already been used by several authors ( Perea et al. 2010, Geiger et al. 2014), the neotype designation stabilizes the use of the name A. kotschyi rather than destabilizes it by transferring it to a species of Pseudophoxinus , which is only indicated by the branched anal-fin ray count.

ICZN (1999: Art. 75.3) prescribes seven qualifying conditions to designate a neotype. Art. 75.3.1. require a statement that the neotype is designated with the express purpose of clarifying the taxonomic status of a nominal taxon. As A. kotschyi cannot be identified from the description, no type is left and two similar species occur at the type locality, only a neotype designation clarifies the taxonomic status of the species. Art. 75.3.2. requires a statement of the characters that the author regards as differentiating the species from its congeners. The diagnosis given below satisfies this requirement. Art. 75.3.3. requires data and description sufficient to ensure recognition of the specimen designated. The diagnosis and description given below satisfies this requirement. Art. 75.3.4. requires that the author's reasons for believing the name-bearing type specimen(s) to be lost or destroyed be stated, together with the steps taken to trace it or them. No type material was found in the Steindachner collection at NMW, which is the only repository known to contain his fish specimens (H. Wellendorf, NMW, pers. comm., 23 Sept 2008). Art. 75.3.5. requires evidence that the neotype be consistent with what is known of the former name-bearing type from the original description. Some of the most important diagnostic characters of the species (see above) are visible in the neotype. Art. 75.3.6. requires that the neotype comes from a location as close as practicable to the original type locality, meaning from Arsuz, which it does. We see no reason to believe, that Steindachner's Arsus is different from the today city of Arzus. Art. 75.3.7. requires a statement that the neotype is the property of a recognized scientific or educational institution, cited by name, that maintains a research collection, with proper facilities for preserving name-bearing types, and that makes them accessible for study. IUSHM fulfils this requirement.

Figures

FIGURE 1.Alburnus kotschyi, IUSHM 37900-253, neotype, 79.2 mm SL; Turkey: Arsuz.