Romanogobio skywalkeri, Friedrich & Wiesner & Zangl & Daill & Freyhof & Koblmüller, 2018

Friedrich, Thomas, Wiesner, Christian, Zangl, Lukas, Daill, Daniel, Freyhof, Jörg & Koblmüller, Stephan, 2018, Romanogobio skywalkeri, a new gudgeon (Teleostei: Gobionidae) from the upper Mur River, Austria, Zootaxa 4403 (2), pp. 336-350 : 340-348

Romanogobio skywalkeri , new species

( Fig.2–3 )

Holotype: NMW 99058 , 64 mm SL; Austria: Styria prov.: River Mur at Unteraich ; 47.403°N 15.240°E; T. Friedrich, 24 Nov 2016.

Paratypes: FSJF 3688 , 5, 83–96 mm SL; NMW 99059, 2, 73–88 mm SL; Austria: Styria prov.: River Mur at Foirach ; 47.403°N 15.176°E; T. Friedrich, 24 Nov 2016. — NMW 98639 , 1, 95 mm SL; NMW 98641 , 3, 47–51 mm SL ; NMW 99060, 5 , 46–60 mm SL; Austria: Styria Prov.: Mur at Unteraich ; 47.403°N 15.240°E; T. Friedrich, 4 Nov 2014. — NMW 98640, 9, 40–53 mm SL; Austria: Styria Prov.: Mur at Unteraich ; 47.403°N 15.240°E; Mur at St. Dionysen ; 47.413°N 15.204°; Mur at Proleb ; 47.395°N 15.142°E; Mur at Fisching ; 47.171°N 14.731°E; T. Friedrich, 4 Nov 2014.

Diagnosis. Based on our COI data, R. skywalkeri is most closely related to R. banarescui . It is distinguished from this species by lacking epithelial crests on the predorsal back (vs. present), having 12–14 total pectoral-fin rays (vs. 10–11) and 8½ branched dorsal-fin rays (vs. usually 7½). Romanogobio skywalkeri is distinguished from R. antipai , R. carpathorossicus , R. kesslerii and R. vladykovi from Danube drainage by lacking epithelial crests on the predorsal back (vs. present). Romanogobio skywalkeri is distinguished from R. uranoscopus from the Danube drainage by having a shorter barbel (barbel reaching to the posterior eye margin or just shortly beyond vs. reaching always beyond the posterior eye margin, often to the operculum), 8½ branched dorsal-fin rays (vs. 7½, Table 3) and the midlateral dark-grey blotches being usually isolated from the dark-grey saddles on the back (vs. usually fused behind the dorsal-fin base). The breast was naked in all but one individuals of R. skywalkeri examined for this character (n=20). Only one individual had one single scale on the breast. A very variable breast squamation pattern was observed in the R. uranoscopus examined (see below) and this is also reported by Bănărescu et al. (1999). Squamation pattern is ranging from a fully scaled breast to an almost naked breast with few isolated scales. A fully naked breast was not found in R. uranoscopus . Romanogobio skywalkeri is further distinguished from R. vladykovi and R. belingi from the North Sea, Baltic and Black Sea basins, by having 8½ branched dorsal-fin rays (vs. usually 7½), the barbel reaching to the posterior eye margin or just shortly beyond (vs. reaching to the middle of the eye or slightly beyond, never beyond the posterior eye margin), a longer pectoral fin (pectoral fin reaching to or almost to the pelvic-fin origin vs. usually reaching to the middle between the pectoral- and pelvic-fin origins). In R. skywalkeri the posteriormost caudal peduncle is slightly deeper than wide (vs. much deeper than wide in R. vladykovi and R. belingi ).

Description. See figures 2–3 for general appearance and Table 2 for morphometric data. Very elongate species, with streamlined body shape. Greatest body depth at dorsal-fin origin, almost continuously decreasing towards caudal-fin base. Greatest body width at pectoral-fin base. Section of head trapezoidal, flattened on ventral surface. Body and caudal peduncle slightly compressed. Depth of caudal peduncle 3–4 times in its length. Caudal peduncle slender and moderately compressed. Pelvic-fin origin below first or second branched dorsal-fin ray. Analfin origin clearly behind vertical of dorsal-fin base. Pectoral fin reaching to or almost to pelvic-fin origin. Pelvic fin reaching to anal-fin origin. Anus closer to anal-fin base than to pelvic-fin base. Dorsal-fin margin concave, caudal fin forked. Mouth inferior, horseshoe shaped. Upper lips thin and smooth. Lower lip shallow, fused with throat. A single pair of maxillary barbels reaching to posterior eye margin or slightly beyond. Largest recorded specimen 138 mm TL.

Dorsal fin with 7½ (1), 8½ (19) or 9½ (1) branched rays. Anal fin with 6½ (19) or 7½ (2) branched rays. Caudal fin with 9+8 (21) branched rays. Pectoral fin with 12 (7) 13 (5) or 14 (9) branched rays. Pelvic fin with 7 (21) branched rays. Body covered by cycloid scales. Breast without scales, in one individual, one scale on middle of breast. No epithelial crests on scales. Lateral line complete, with 40–43 scales on body and 1–3 on caudal-fin base. Scale rows between lateral line and dorsal-fin origin 5 (4), 6 (16) or 7 (1) and between lateral line and pelvic fin origin 3 (7) or 4 (14).

Coloration. In life: A greenish hue when freshly caught. Top of head and back pale-brown with indistinct brown, rounded or irregularly-shaped blotches; 1–2 blotches on predorsal back, one at dorsal-fin origin, 2–3 behind dorsal-fin base, not fused with midlateral blotches. Flank silvery or grey with 6–9 dark-grey, roundish mid-lateral blotches, fading in individuals larger than 75 mm SL. A whitish blotch on upper and lower caudal-fin base interrupted by a brown extension of last midlateral blotch along lateral line. Pigment cells denser on upper and lower extremities of exposed part of flank scales forming dark-grey lines on back and upper flank in some individuals. In other individuals, scale margins brown forming a reticulate pattern or scale pockets brown forming a spotted pattern. A short black band between middle of upper lip and eye margin and a black, irregularly shaped blotch below eye. Operculum with a dark-grey or dark brown blotch. Dorsal- and pectoral-fin rays with 2–3 and caudal fin with 2–4 bands of elongated blotches. Pelvic and anal fins without or with few small black blotches. Fins hyaline in juveniles, usually yellowish in adults.

Etymology. Named for Luke Skywalker, the hero of the movie “Star Wars: Episode IV—A New Hope” (Lucasfilms, Twentieth Century Fox, 1977). As common name emerald gudgeon fits the line with common names of other Romanogobio species and reflects the green hue of the fish when observed in his natural habitat or freshly caught.

Distribution. Known from a river section of about 85 km in the upper Mur between the villages Fisching and Laufnitzdorf ( Fig.4 ).

Ecology and conservation. Romanogobio skywalkeri occurs together with Gobio obtusirostris . Romanogobio skywalkeri is highly rheophilic and was found to be most abundant on gravel banks with high flow velocities and water depths between 0.1 and 0.4 meters ( Fig.5 ). All age classes were found in this type of habitat. Here it cooccurs with juvenile (0+ and 1+) Thymallus thymallus and Barbatula barbatula . Juvenile (0+) R. skywalkeri were also found in small side channels with high current velocities together with juvenile T. thymallus . Around 50% of the distribution area of R. skywalkeri is situated in the Natura 2000 Site “Ober- und Mittellauf der Mur mit Puxer Auwald, Puxer Wand und Gulsen” with no migration obstacles. Nevertheless, with several additional hydropower projects in the planning or even construction stages in the Mur River, it is of urgent necessity to critically assess human impacts, which may directly affect the habitat of this species which, as currently understood, appears to be endemic to Austria.

Romanogobio skywalkeri

: NMW 98639, 1 ; Austria: Mur at Unteraich, 47.402°N 15.240°E (GenBank accession number: MG797658 ). — NMW 98641, 3 ; Austria: Mur at Unteraich, 47.402°N 15.240°E (GenBank accession numbers: MG786142 , MG786162 , MG786178 ). — NMW 98716, 1 ; Austria: Mur at Unteraich, 47.402°N 15.240°E (GenBank accession number: MG786143 ). — NMW 98640, 9 ; Austria: Mur at Unteraich, 47.402°N 15.240°E, Mur at St. Dionysen , 47.413°N 15.204°E, Mur at Proleb , 47.395°N 15.142°E, Mur at Fisching, 47.171°N 14.731°E (GenBank accession numbers: MG786146 , MG786156 , MG786161 , MG786171 , MG786172 , MG786173 , MG786176 , MG786183 , MG786186 ). — NMW 99058, 1 ; Austria: Mur at Unteraich, 47.402°N 15.240°E (GenBank accession number: MG786145 ). — NMW 99059, 2 ; Austria: Mur at Foirach, 47.403°N 15.176°E (GenBank accession numbers: MG786160 , MG786187 ). — NMW 99060, 5 ; Austria: Mur at Unteraich, 47.402°N 15.240°E (GenBank accession numbers: MG786154 , MG786159 , MG786163 , MG786168 , MG786181 ). — NMW 99061, 3 ; Austria: Mur at Unteraich, 47.402°N 15.240°E (GenBank accession numbers: MG786147 , MG786151 , MG786177 ). — KFUG ABOL6 , 1 ; Austria: Mur at Unteraich , 47.402°N 15.240°E ( GenBank accession number: MG786182 ).—without voucher, 1; Austria: Mur at Laufnitzdorf, 47.290°N 15.326°E (GenBank accession number: MG751105 ).

Figures

FIGURE 2. Romanogobio skywalkeri, NMW 99058,holotype, 65 mm SL; Austria:River Murat Bruck a.d. Mur.(photographs by Maria Bräuner)

FIGURE 3. Romanogobio skywalkeri, from the top, not preserved, 109 mm SL; FSJF 3688, 91 mm SL, 96 mm SL; Austria: River Mur at Oberaich.

FIGURE 4. Distribution of R. skywalkeri, MurRiver, Austria

FIGURE 5. Mur River, Austria, habitat of R.skywalkeri.