FISH OF THE FAMILY CYPRINIDAE IN THE WATER BODIES OF UKRAINE - V. V. Zamorov - 2015

GENUS BOBYRETS (BOBHYRETS) - PETROLEUCISCUS (KESSLER)

6 species are known, of which one is found in Ukraine.

Danube minnow (bobyrets) - Petroleuciscus borysthenicus (Kessler)

Morphological features: D III (7) 8 (9); А III 8-10 (11); Р І (12) 13-15 (16); VII (7) 8; І. І. (34) 35-40 (41); Squ₁ 7; Squ₂ (2,0) 2,5-3,0 (3,5); vert. (31, 32) 33-38 (39); sp. br. (5) 6-10 (11); d. f. 2.5-5.2 (56,2%), 2.5-5.3 (7,6%), 1.5-5.2 (6,2%), 2.5-4.2 and 2.4-5.2 (5,4% each), 3.5-5.2 and 1.5-5.1 (1,1% each), 1.4-5.2, 1.4-5.1 and 0.5-5.1 (0,7% each), all other variations: 3.5-5.1, 3.4-5.2, 2.6-5.1, 2.6-5.2, 2.6-5.3, 2.6-3.4, 2.55.0, 2.5-4.1, 2.4-4.3, 2.4-4.1, 2.3-5.1, 1.5-5.3, 1.5-4.2, 1.4-4.2, 1.3-5.2, 0.4-4.1, 0.2-2.0 account for about 0,4% each of the total number of fish analyzed. Maximum length 11 cm, fish weight 17 g, lifespan 7-8 years (Fig. 55).

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Fig. 55. Danube minnow Petroleuciscus borysthenicus

Body moderately elongate, slightly compressed laterally, rather thick and deep. The maximum body depth averages 25.4 to 28.6% (22.8-32.5) of the standard body length and exceeds the minimum body depth by more than 2.5-3.0 times.

The dorsal and ventral profiles are smoothly convex, with a faintly indicated hump originating just behind the nape. The back and belly (especially behind the pelvic fins) are rounded. The caudal peduncle makes up 18.7-24.6% of the body length. The dorsal fin is truncated straight, slightly rounded at the apex; the anal fin is usually rounded, without a notch; the paired and caudal fins are rounded, the latter with a small notch, and its lower lobe is typically longer than the upper one. The dorsal fin originates behind the vertical of the pelvic fin base. The first hard ray in the dorsal and anal fins is very small, almost imperceptible. The pectoral fins are long, exceeding half the pectroventral distance. At the Base of the pelvic fins on the outer side, there is an elongated scale. Scales are of medium size, covering the entire body quite densely. The lateral line is complete, occasionally interrupted by one to six scales, arches downward toward the belly, and in the anterior part of the body extends from the trunk onto the HEAD, where it is arranged in several rows. The head is small, its length generally equal to the maximum body depth.

The snout is short, relatively blunt, more than twice as small as the head depth at the nape. The Mouth is small, terminal, obliquely cut, with its tip at the level of the middle of the eye or sometimes slightly below it. The eyes are rather large, with the diameter typically exceeding the length of the upper jaw. The forehead is broad, flat (slightly convex in juveniles), averaging 35.6-38.9% of the head length. Gill rakers are short, sparsely spaced. Pharyngeal Teeth are quite robust, arranged in two rows, usually serrated (almost entirely smooth in larger specimens), with a small hook at the tip.

Distributed mainly in the lower reaches of rivers belonging to the Aegean, Black, Azov, and Marmara Sea basins.

In Ukraine, it occurs in the lower basins of the Danube, Dniester, Southern Bug, and Dnieper rivers; it has been recorded in the Dniester and Dnieper-Bug estuaries, in the middle and upper Dnieper basins, as well as in the lower reaches of the rivers along the northern coast of the Sea of Azov.