Alburnus sava, Bogutskaya, Nina G., Zupancic, Primoz, Jelic, Dusan, Diripasko, Oleg A. & Naseka, Alexander M., 2017

Bogutskaya, Nina G., Zupancic, Primoz, Jelic, Dusan, Diripasko, Oleg A. & Naseka, Alexander M., 2017, Description of a new species of Alburnus Rafinesque, 1820 (Actinopterygii, Cyprinidae, Leuciscinae) from the Kolpa River in the Sava River system (upper Danube drainage), with remarks on the geographical distribution of shemayas in the Danube, ZooKeys 688, pp. 81-110 : 83-85

Alburnus sava sp. n. Figs 1, 2, 3a

Holotype.

MNCN 291345, 173.6 mm SL, female, Kolpa River at Griblje (45.58°N 15.30°E), Slovenia, 3 Oct 2013, coll. B. Levai.

Paratypes.

MNCN 291346-53, 8, 105−151.5 mm SL, same data as holotype; HDBI 255, 218 mm SL, Kupa [Kolpa] River at Ozalj (45.62°N 15.47°E), Sept 2011, Croatia, coll. D. Jelić; HDBI 1224, 3, 62.9−79.8 mm SL, same data as HDBI 255.

Diagnosis.

Alburnus sava sp. n. is distinguished from all other species of Alburnus in the Danube drainage by having 23−27, usually 24−26, gill rakers; the ventral keel usually completely scaled (scaleless maximum 15% of the keel length); 15−16 (mode = 15) branched pectoral-fin rays; the length of gill raker 65−70% of the length of the opposite outer gill filament; and a relatively long lower jaw (37−40% HL, 112−130% interorbital width).

Description.

The general appearance of Alburnus sava sp. n. can be seen in Figure 1. Relative measurements are provided in Table 1. Variation in ten (of the 16) examined meristic characters is provided in Table 2. The largest specimen, a spent female, is 218 mm SL. As the examined samples are rather small in number of specimens and contain individuals with a wide range in SL, Table 1 also presents the range and mean for the holotype and size groups separately. Body depth at the dorsal-fin origin in the 218 mm-long specimen represented 27% SL and considerably exceeded the range in body depth of smaller specimens (20−23% SL). The same is found for the depth of the caudal peduncle, 10% SL (60% length of caudal peduncle or 1.7 times in its length) vs. 9% (46−54% length of caudal peduncle or 1.9−2.2 times in its length), respectively. However, head length and eye diameter are clearly negatively allometric. The head length mean in the small-size group (63−80 mm SL) is 25.8% SL vs. 22.7% SL in specimens 174 and 218 mm SL; in smaller specimens the head length considerably exceeds the body depth while in the largest specimen it is much smaller than the latter. The eye diameter mean is 7.5% SL (29% HL) in the small-sized group (63−80 mm) vs. 5.1% SL (22.5% HL) in 218 mm long specimen.

The mouth is upturned and the mouth cleft is straight. The tip of the mouth is about at a level with the upper margin of the pupil. The lower jaw is long, its length 112−130% interorbital width. The chin is variably developed (Fig. 1). The holotype has a well developed chin while the chin of the paratype is smoothed and slightly projected.

The ventral keel between the pectoral-fin bases and the anus is well pronounced but not sharp and usually completely covered by scales (in 8 specimens, including the holotype) or scaleless (exposed) for 1−2 scales only (Table 2), reaching up to 15% of the keel.

Dorsal fin with 3 unbranched and 8½ branched rays. Anal fin with 3 unbranched and 15½ or 16½ branched rays (Table 2). Origin of anal fin located on (in three specimens) or slightly behind the vertical of the dorsal-fin insertion (Fig. 2).

Number of gill rakers 23−27, mode 24−26 (Table 2). In two specimens examined (80 and 218 mm SL) length of gill raker 65% and 70% (Fig. 3a) the length of the opposite gill filament in the outer row. Pharyngeal teeth 2.5-5.2 (n =2 paratypes).

Total lateral-line scales number (61)63−64, mode 63; lateral-line scales to the posterior margin of hypurals 57−62, mode 60. Total vertebrae 44−45, 23−24 abdominal and 20−21 caudal (Table 2; Fig. 2).

No nuptial tubercles in the examined material. Four dissected individuals were females. Overall colouration is silvery with no orange or red pigment at fin bases and no faint dark midlateral stripe in both freshly caught and preserved specimens.

Distribution and habitat.

The species is currently known from the Kolpa River drainage, a tributary of the Sava River in the upper Danube drainage, Black Sea basin (Fig. 4). Alburnus sava sp. n. is a potamadromous species, occurring in streams and rivers with moderate to rapid current and a gravel and cobble bottom; in spring, during the spawning season, the species migrates upstream to smaller tributaries to shallow riffles where they spawn.

Etymology.

The species name refers to the Sava River. A noun in apposition.

Vernacular name.

Local names are bucov or velika pliska in Croatian and Serbian, pegunica in Slovene.