Alburnus danubicus Antipa, 1909

Iftime, Alexandru & Oţel, Vasile, 2025, An annotated systematical checklist of the Romanian ichthyofauna, Zootaxa 5654 (1), pp. 1-64 : 14

Alburnus danubicus Antipa, 1909

A native, localized fresh- and brackish-water species, living in flowing or stagnant water in the lower Danube (below the Iron Gates), its Delta, the Razim lagoon system, the Black Sea from the Danube mouths to Agigea, and the Siutghiol littoral lake ( Bănărescu 1964 [as Chalcalburnus chalcoides mento (Agassiz, 1832) ]; Oțel 2007 [as Chalcalburnus chalcoides (Güldenstädt, 1772) ]; Freyhof & Kottelat 2007 [as both A. danubicus and A. sarmaticus Freyhof et Kottelat, 2007 ]; Kottelat & Freyhof 2007 [as both A. danubicus and A. sarmaticus ]; Halasi‐Kovács, 2017; Cocan & MireȘan 2018 [as both A. danubicus and A. sarmaticus ]). Alburnus danubicus s. str. was considered extinct (Freyhof & Kottelat 2007; Kottelat & Freyhof 2007; Cocan & MireȘan 2018; Stefanov, 2019) and A. sarmaticus extremely rare (Oțel 2007; Freyhof & Kottelat 2007; Kottelat & Freyhof 2007; Boltachov 2009; Stefanov & Trickova 2011; Cocan & MireȘan 2018; Stefanov 2019). A sedentary or limited-range potamodromous population was found in the Danube between Tutrakan and Vetren, opposite CălăraȘi county, Romania ( Stefanov 2019), and another right below the Porțile de Fier II dam (Bănărescu, pers. comm.); the latter survives as attested by recent catch-and-release records which allowed provisional identification as A. sarmaticus (Szilagyi, F., 2021, via Moraru, M. F., Ichthyology of Romania Facebook group; Moraru & Oțel id.; Fig. 1 ), i.e. A. danubicus (see taxonomical discussion below).

The shemayas ( Alburnus species, formerly treated as Chalcalburnus ) are morphologically very similar; however, Freyhof & Kottelat 2007 recognize two distinct lower Danube species ( A. danubicus , considered extinct, and A. sarmaticus , still present and with a wider Pontic distribution). Alburnus mento -group shemayas are largely overlapping in diagnostic features ( Parin et al. 2014; Halasi‐Kovács 2017), hence the call for treating all those in the Pontic drainage as a single taxon ( Parin et al. 2014) despite the possible validity of some Pontic species ( Parin et al., 2014). Later, Halasi‐Kovács (2017) argues for the synonymy of A. sarmaticus and A. danubicus , including a neotype designation for the latter, while in parallel Bogutskaya et al. (2017) not only maintain these two species, but describe A. sava as distinct from both; however, Harka & Halasi-Kovács (2024) solve the conundrum by treating the Danubian group as represented by two species ( A. danubicus , which includes A. sarmaticus , and the distinct A. sava ) which we follow here, under the caveat of a fluid taxonomy, as molecular and morphological studies show that the diversity of the shemayas might be overestimated ( Bektas et al. 2020, Bayçelebi et al. 2021).

Figures

FIGURE 1. Alburnus cf. danubicus, captured (and released), Danube at Gârla Mare, 2021, photo Francisc Szilagyi (used here with permission).