Gobio uralensis, Turbanov & Bolotovskiy & Artaev & Gandlin & Levina & Vasil’eva & Levin, 2025

Turbanov, Ilya S., Bolotovskiy, Aleksey A., Artaev, Oleg N., Gandlin, Aleksandr A., Levina, Marina A., Vasil’eva, Ekaterina D. & Levin, Boris A., 2025, On the border of Europe and Asia: Gobio uralensis, a new species of gudgeons (Cypriniformes, Gobionidae) from the Caspian Sea basin, Zoosystematics and Evolution 101 (2), pp. 855-874 : 855-874

Gobio uralensis sp. nov.

Figs 3 , 4 , 8 A (English name – Ural gudgeon, Russian name – уральский пескарь )

Gobio fluviatilis non Cuvier, 1842 – Kessler 1877: 298.

Gobio gobio (non Linnaeus, 1758) – Navozov 1912: 263; Berg 1914: 428 (part.); Bening 1938: 237; Tikhiy 1938: 307; Berg 1949: 640 (part.); Kozhin 1949: 374 (part.); Shaposhnikova 1964: 78; Mitrofanov 1988: 6, fig. 1 (part.); Kottelat 1997: 60 (part.); Bănărescu et al. 1999: 81 (part.); Zinovyev and Baklanov 2007: 54 (part.); Magazov and Rechkalov 2007: 87 (part.); Chibilev and Debelo 2009: 101 (part.); Shevchenko 2018: 122–123.

Gobio volgensis non Vasil’eva, Mendel, Vasil’ev, Lusk & Lusková, 2008 – Bogutskaya et al. 2013: 176, figs 35 a, 36 a (part.); Martynova and Vasil’eva 2021: 529 (part.), figs 1, 2; Vasil’eva et al. 2023: 503 (part.).

Type material.

Holotype • ( IBIW_FS_454 ) 97.7 mm SL, Russia, Republic of Bashkortostan, Abzelilovsky Distr., near Ryskuzhino, Bolshoy Kizil River , 53.3161°N, 58.3351°E, 24 Aug. 2020, O. N. Artaev, A. A. Bolotovskiy, I. V. Pozdeev, I. S. Turbanov leg. Paratypes • 4 spec. ( IBIW_FS_455 ) 70.3–110.4 mm SL, 3 spec. ( ZISP 57042 ) 69.8–73.4 mm SL, 3 spec. ( ZMMU P-24633 ) 68.1–75.7 mm SL, same data as holotype .

Additional material.

• 7 spec. ( IBIW_FS_456 ) 40.9–64.4 mm SL, same data as holotype and paratypes • 4 spec. ( IBIW_FS_457 ) 34.8–42.7 mm SL, Russia, Orenburg Region, Pervomaysky Distr., near Lyashevo, Chagan River , 51.8514°N, 51.4965°E, 22 May 2021, O. N. Artaev, A. A. Bolotovskiy, A. V. Kutuzov leg. • 1 spec. ( IBIW_FS_458 ) 72.5 mm SL, Russia, Orenburg Region, Saraktashsky Distr., near Krasnogor, Ural River , 51.5591°N, 56.1224°E, 23 May 2021, O. N. Artaev, A. A. Bolotovskiy, A. V. Kutuzov leg. • 5 spec. ( IBIW_FS_459 ) 38.9–50.3 mm SL, 32 spec. (IBIW FS _ 465) 27.9–39.9 mm SL, Russia, Orenburg Region, Saraktashsky Distr., near Nikolskoe, Sakmara River , 52.0018°N, 55.7371°E, 24 May 2021, O. N. Artaev, A. A. Bolotovskiy, A. V. Kutuzov leg. • 2 spec. ( IBIW_FS_460 ) 85.0– 87.5 mm SL, Russia, Orenburg Region, Sakmarsky Distr., near Svetlyi, Kargalka River , 52.0835°N, 55.1283°E, 24 May 2021, O. N. Artaev, A. A. Bolotovskiy, A. V. Kutuzov leg. • 11 spec. ( IBIW_FS_461 ) 47.2–80.2 mm SL • 15 spec. (IBIW FS _ 466) 33.7–47.6 mm SL, Russia, Orenburg Region, Oktyabrsky Distr., Oktyabrskoe, Bolshoy Yushatyr River , 52.3631°N, 55.5008°E, 24 May 2021, O. N. Artaev, A. A. Bolotovskiy, A. V. Kutuzov leg. • 1 spec. ( IBIW_FS_462 ) 71.8 mm SL, Russia, Republic of Bashkortostan, Kugarchinsky Distr., near Aznagulovo, Nakas River , 52.6431°N, 56.2436°E, 24 May 2021, O. N. Artaev, A. A. Bolotovskiy, A. V. Kutuzov leg. • 17 spec. ( IBIW_FS_463 ) 57.9–82.1 mm SL, Russia, Republic of Bashkortostan, Zianchurinsky Distr., near Verkhniy Muinak, Uskalyk River , 51.9687°N, 56.6878°E, 25 May 2021, O. N. Artaev, A. A. Bolotovskiy, A. V. Kutuzov leg. • 5 spec. ( IBIW_FS_464 ) 37.2–81.4 mm SL, Russia, Republic of Bashkortostan, Zianchurinsky Distr., upstream Itkulovo, Assel River , 51.9047°N, 56.8683°E, 25 May 2021, O. N. Artaev, A. A. Bolotovskiy, A. V. Kutuzov leg.

Etymology.

The adjective uralensis comes from the name of the Ural River, which literally means lives in the basin of this river.

Diagnosis.

Gobio uralensis sp. nov. is distinguished by a combination of characters, none of which is unique, as follows: predorsal length 47.4–52.6 % SL; postdorsal length 36.3–42.1 % SL; body depth 17.4–23.7 % SL; prepelvic length 49.8–56.8 % SL; preanal length 70.2–75.2 SL; snout length 40.9–48.8 % HL; interorbital width 22.3–29.6 % HL; ratio of caudal peduncle length to caudal peduncle depth 2.0–2.8; pharyngeal teeth in two rows, 3.5–5.3; anal fin branched rays 6 1 / 2; number of lateral line scales 39–45, mean 42.1; 12 (mode) predorsal vertebrae; the breast between the pectoral fins is naked; lower lip is interrupted in middle, with a notch between narrower anterior and widening posterior parts.

Description.

General appearance shown in Fig. 3 . Morphometric and meristic data are given in Tables 2 – 4 . Largest recorded specimen – 110.4 mm SL.

Morphometrics.

The body and the caudal peduncle are moderately compressed; the minimum body depth is somewhat greater than the width of the caudal peduncle at the level of the last anal ray. Predorsal length is somewhat more than postdorsal length. The distance between pectoral and pelvic-fin origins is somewhat more than the distance between pelvic and anal-fin origins. The anus is closer to the insertion of the anal fin than to the origin of the pelvic fins; the pelvic fin reaches beyond the anus. Barbels are moderately long; they are usually less than 1 / 3 of the head length and reach up to the middle of the eye but never reach to its posterior edge. Paired fins are moderately long: pectoral fins never reach the pelvic fin insertion; ventral fins never reach the anal fin insertion. The eye is large with a diameter of 17.6–25.2 % of the head length, an eye diameter of 2.2–3.3 times in head depth, and 1.0–1.5 times in interorbital width. The snout is pointed; its length is somewhat longer than the postorbital length. Caudal peduncle is 2.0–2.8 times longer than depth.

Meristics.

Dorsal fin margin is concave, with 3 unbranched and 7 1 / 2 branched rays (only one specimen had 8 1 / 2 rays); anal fin margin is concave or straight, with 3 unbranched and 6 1 / 2 branched rays; pectoral fin branched ray numbers vary within 13–17 (mode 16 and 15 in left and right, respectively); and pelvic fin branched ray numbers vary within (5) 6–8 (mode 7). The shape of the caudal fin is variable; the two lobes are sharpened or rounded, with a notch in the middle. Body is covered by scales. Lateral line includes 39–45 total scales (mode 42) and 11–15 circumpeduncular scales (mode 12). Two-five gill rakers (modes 4 and 5) on outer side of first gill arch. Pharyngeal teeth are in two rows, 3.5–5.3, slightly hooked at tip (Fig. 4 ).

Total vertebrae 39–42 (mode 40), 20–22 (mode 21) abdominal, including 11–13 predorsal and 18–21 (mode 19) caudal, including 1–3 preanal and 16–19 postanal vertebrae. The radiograph of the holotype is given in Fig. 5 .

Qualitative characters.

The breast in front of the posterior edge of the base of the pectoral fins usually lacks scales; some individuals have 1–3 scales along the midline towards the throat [character state 1 following Naseka et al. (2006)] (Fig. 8 A ).

Coloration.

Body is dark olive-brown above, merging into a light silvery underside. There are large, more or less rounded 6–14 (often 10) blotches on flank located along the lateral line. The color of the fins corresponds to the color of the body with several rows of small dark dots on the dorsal and caudal fins. Live coloration is given in Figs 3 A, D, E , 8 A .

Distribution.

The type specimens were collected from the Bolshoy Kizil River, a tributary of the Ural River, near Ryskuzhino (53.3161°N, 58.3351°E), Republic of Bashkortostan, Russia (see Fig. 6 ). All other gudgeons genetically confirmed as the same species were caught in different locations in the Ural River basin (see materials). Although we suppose that the whole Ural River basin is inhabited by the Ural gudgeon, one may not exclude that some parts of the extended Ural drainage are inhabited by other species. According to Shaposhnikova (1964), the gudgeon is widespread throughout the Ural River. The gudgeon is especially abundant in the mountain tributaries of the Ural and in its upper reaches, where it is numerous in riffles and sandbanks; this is partly confirmed by the data of Martynova and Vasil’eva (2021) as well as by our observations.

Biology.

In the Ural River near Orenburg, the gudgeon spawns from the middle of the twentieth days of April to early or mid-May, but individual spawning specimens are caught throughout the summer ( Navozov 1912). Spawning is multiple ( Shaposhnikova 1964). In all areas of the Ural basin, regardless of the time of year, larvae of Tendipedidae ( Insecta: Diptera ) are the main food item beginning from the first year of life. In addition, larvae of Heleidae ( Insecta: Diptera ), Oligochaeta (Annelida), larvae of Ephemeroptera ( Insecta), Gastropoda (Mollusca), plant remnants, and diatom algae were also detected. In juveniles (up to 47 mm), Cladocera and Copepoda (Crustacea) as well as diatoms and other algae predominated in the food bolus ( Shaposhnikova 1964).

Comparative remarks.

As we have already noted above, in the earliest faunal studies, the gudgeons from the Ural River basin were identified as Gobio gobio . However, according to the latest data, G. gobio is distributed in the basins of the Atlantic Ocean, the North, Baltic and White Seas (including Great Britain and the upper Danube basin), but not in the Caspian Sea basin ( Dyldin et al. 2023). At the same time, G. gobio is well differentiated from G. uralensis sp. nov. by a narrow lower lip with no interception between the anterior and posterior parts (vs. the lower lip is interrupted in the middle, with a groove between narrower anterior and wider posterior parts in G. uralensis sp. nov.); its minimum body depth always exceeds 30 % of the length of the head and 40 % of the length of the caudal peduncle ( Vasil’eva et al. 2023).

Geographically, the two species closest to the new species are the Siberian gudgeon G. sibiricus (Figs 7 C, D , 8 C ), distributed from the Ob’ to Lena basins (including the Nura River in Kazakhstan), and G. volgensis (Figs 7 A, B , 8 B ), known from the Volga River basin.

In turn, the new species is morphologically almost indistinguishable from the Volga gudgeon; therefore, the Ural populations were previously identified as G. volgensis ( Vasil’eva et al. 2023). According to the materials of this study, G. volgensis from the Chusovaya, Belaya, Ashkadar and Dema rivers (neighboring rivers of the Volga River basin to the typical habitats of the Ural gudgeon) have a slightly higher total number of lateral line scales – a range 41–45 and median of 42.5 (vs. a range 39–45, median of 42 in G. uralensis sp. nov.), as well as a higher number of scales above lateral line – a range 5–6.5 and median of 6 (vs. a range 4–6, median of 5.5 in G. uralensis sp. nov.). Besides, small differences in the mean values of some morphometric characters are observed between the combined samples of both species (see Table 3 ).

Contrast to G. uralensis sp. nov. the minimum body depth in G. sibiricus , always exceeds 30 % of the length of the head and 40 % of the length of the caudal peduncle (vs. usually exceeds the half of caudal peduncle length) and the number of blotches on flank along the lateral line in this species varies from 6 to 11 (vs. usually less than 10) ( Vasil’eva et al. 2023). In addition, according to the materials of the present study, G. sibiricus from the Kushtumga, Koelga, and Sinara rivers (neighboring rivers of the Ob’ River basin to the typical habitats of the Ural gudgeon) has a fewer number of lateral line scales to hypural and total number of lateral line scales (ranges 36–40 and 40–43, medians 39 and 42, respectively, vs. ranges 36–42 and 39–45, medians 37.5 and 41 in G. uralensis sp. nov.) and a smaller number of predorsal vertebrae (range 11–13, median 12 vs. range 10–12, median 11 in G. uralensis sp. nov.). Besides, small differences in the mean values of some morphometric characters are observed between the combined samples of both species (see Table 3 ).

LDA analysis explained 86.88 % of shape variations by the first LD axis and 13.12 % by the second LD axis for all specimens of three species examined above. LDA of morphometric characters shows that G. uralensis sp. nov. together with G. volgensis is strongly different from G. sibiricus by LD 1 in the following features: length caudal peduncle / depth caudal peduncle, interorbital length / eye diameter, and depth caudal peduncle / SL (Fig. 9 ). Gobio uralensis sp. nov. is slightly overlapping with G. volgensis by LD 2 in the following features: head depth through nape / eye diameter, interorbital length / eye diameter, and length caudal peduncle / depth caudal peduncle. Specimens of G. volgensis are located mainly on the positive side of LD 2, while specimens of G. uralensis sp. nov. are situated mainly on the negative side of LD 2. The statistic values for LDA were as follows: Wilks’ Lambda = 0.037001, approx. F (62, 160) = 10.835, p <0.0001, indicating good species discrimination. Coefficients of linear discriminants see Suppl. material 4.

Further morphological comparison with a number of geographically close gudgeon species distributed out of the Volga and Ob’ basins has been done based on literature data (except for G. acutipinnatus , some features of which were studied by authors using materials from the ZISP collection).

Another gudgeon species indicated in the literature for the Ob’ River basin is G. acutipinnatus (Fig. 7 E ). This species was described from Lake Markakul in the Irtysh basin in Kazakhstan but today is also recorded for the water bodies of Russia, Mongolia, and China ( Kottelat 2006; Yang et al. 2016; Yi and Fu 2020; Fricke et al. 2025). Compared to G. acutipinnatus from Lake Markakul ( ZISP collection, 10 specimens), based on the materials of this study, G. uralensis sp. nov. has significantly (Kruskal-Wallis test, see Table 4 ) more pectoral fin branched rays, median 15.5 (vs. median 14.25), more total lateral line scales, median 42 (vs. median 41.5), and fewer scales below lateral line, median 3.75 (vs. median 4).

Compared to G. lepidolaemus Kessler, 1872 from the Zeravshan and Syr-Darya rivers based on the materials of Nikolsky (1936), G. uralensis sp. nov. has a greater number of lateral line scales (39–45, mean 42.1 vs. 36–42, mean 39.6) and anal fin branched rays 6 1 / 2 (vs. 5 1 / 2).

Compared to Gobio nigrescens from the Hari River based on the materials of Mousavi-Sabet et al. (2016), G. uralensis sp. nov. has longer head (as % of SL) 25.6–30.0 (vs. 22.3–25.8), more predorsal lenght 47.4–52.6 (vs. 43.3–45.4), more prepelvic length 49.9–56.8 (vs. 46.4–50.7), and more preanal length 70.2–75.2 (vs. 67.1–69.1), less depth of caudal peduncle 7.2–8.8 (vs. 8.3–9.3), less body width 12.7–17.8 (vs. 17.3–18.7), has shorter caudal peduncle 16.3–22.8 (vs. 21–24), has less head depth (in percent of HL) 52.6–62.0 (vs. 65–69), less interorbital width (in percent of HL) 22.3–29.6 (vs. 34–41), more snout length (in percent of HL) 40.9–48.8 (vs. 35–40), less anal fin branched rays 6 1 / 2 (vs. 5 1 / 2) and less circumpeduncular scales 11–15 (vs. 16).

Compared to Gobio latus Anikin, 1905 from Lake Issyk-Kul based on the materials of Berg (1949), G. uralensis sp. nov. has more numbers of pharyngeal teeth in minor row – 3.5–5.3 (vs. 2.5–5.2).

Compared to Gobio multipunctatus from the Emel River, Lake Alakol basin based on the materials of Vasil’eva et al. (2023), G. uralensis sp. nov. has less depth of caudal peduncle 7.2–8.8 (vs. 8.0–10.0), shorter caudal peduncle 16.3–22.8 (vs. 20.2–24.9), less dorsal fin depth 18.2–23.1 (vs. 21.8–26.2), more number of pharyngeal teeth in minor row – 3.5–5.3 (vs. 2.5–5.2), and has less black blotch numbers on body — often 10 (vs. usually more than 12).

Compared to Gobio holurus from the rivers of the western part of the Caspian basin based on the materials of Freyhof and Naseka (2005), G. uralensis sp. nov. has a naked breast between the pectoral fins (vs. the scaled breast). Compared to G. holurus from the Podkumok and Sunzha rivers ( Berg 1914), G. uralensis sp. nov. has longer head (as % of SL) 25.6–30.0 (vs. 23.8–24.7), less postdorsal length 36.3–42.1 (vs. 42.6–43.1), more dorsal fin depth 18.2–23.1 (vs. 16.1–17.9), more anal fin depth 14.9–18.0 (vs. 13.9–14.1), and more ratio of caudal peduncle length to caudal peduncle depth 2.0–2.8 (vs. 1.9–2.0).

Figures

Figure 3. Lateral view of Gobio uralensis sp. nov.: A – C. Bolshoy Kizil River near Ryskuzhino (A, B. Holotype; C. Paratype); D. Uskalyk River near Verkhniy Muinak; E. Ural River near Krasnogor (right side, inverted image). A, D, E. Live coloration; B, C. After fixation in 10 % formalin (5 months), then transferred to 70 % ethanol. Scale bar: 10 mm.

Figure 4. Dentition of pharyngeal bones (3.5–5.3) of Gobio uralensis sp. nov. Scale bar: 0.5 mm.

Figure 5. Radiograph of Gobio uralensis sp. nov., holotype: Scale bar: 10 mm.

Figure 6. Type locality of Gobio uralensis sp. nov. – Bolshoy Kizil River near Ryskuzhino (53.3161 ° N, 58.3351 ° E, 24 Aug. 2020).

Figure 7. Lateral view of Gobio spp. (comparative material): A, B. G. volgensis (A. Chusovaya River near Kosoy Brod; B. Buzuluk River near Fedorovka (right side, inverted image )); C, D. G. sibiricus (C. Koelga River near Zvyagino; D. Sinara River near Bulzi), E. G. acutipinnatus, syntype ZISP 26865 (Lake Markakol). A – D. Live coloration; E. Preserved specimen of 1936 year. Scale bar: 10 mm.

Figure 8. Breast and belly view of Gobio spp.: A. G. uralensis sp. nov., Ural River near Krasnogor; B. G. volgensis, Schegrinka River near Jidobuzhi; C. G. sibiricus, Koelga River near Zvyagino. Scale bar: 10 mm.

Figure 9. Linear Discriminant Analysis (LDA) of Gobio uralensis sp. nov. (n = 77), G. volgensis (n = 46), and G. sibiricus (n = 37) based on 31 morphometric indexes and ratios.