Carasobarbus harterti ( Guenther , 1901) Guenther, 1901

Borkenhagen, Kai & Krupp, Friedhelm, 2013, Taxonomic revision of the genus Carasobarbus Karaman, 1971 (Actinopterygii, Cyprinidae), ZooKeys 339, pp. 1-53 : 25-27

Carasobarbus harterti ( Guenther, 1901) comb. n.

Barbus harterti Günther 1901: 367.

Material.

Type material. Syntypes: BMNH 1901.7.26:4-5, 2, Morocco, Oued Oum er Rbia [33°19'40"N, 8°20'2"W], E. Hartert.

Non-type material. Oued Oum er Rbia drainage. BMNH 1902.7.28:27-33, 7; BMNH 1903.10.29:11-15, 8, Morocco, Oued Oum er Rbia [33°19'40"N, 8°20'2"W], F. Riggenbach. - BMNH 1903.7.1:5-7, 3, Morocco, Oued Oum er Rbia near El Jadida [33°15'18"N, 8°30'22"W], F. Riggenbach. - MNHN 1912-0089, 1; MNHN 1912-0090, 1; MNHN 1912-0091, 1; MNHN 1912-0092, 1; MNHN 1912-0093, 1, Morocco, Oued Oum er Rbia near Azemmour [33°17'22"N, 8°20'33"W], C. du Gast, 1912. - SMF 33366, 1; SMF 33368, 1; SMF 33370, 1, Morocco, Oued Oum er Rbia (32°18'53"N, 6°54'33"W), A. Azeroual et al., 9 Apr 2011.

Oued Tennsift drainage. BMNH 1902.7.28:34, 1, Morocco, Oued Talmest [31°52'15"N, 9°18'31"W], F. Riggenbach.

Diagnosis.

Two pairs of long barbels; 31 to 38 scales in the lateral line and 13 to 17 scales around the least circumference of the caudal peduncle; dorsal fin longer than anal fin and less than 15 % of the length of its last unbranched ray is flexible, dorsal profile of the head straight.

Description.

The body is of moderate height and without a nuchal hump. The head is triangular with almost straight dorsal and ventral profile (Figs 19, 20). The head length is shorter than the body depth (Fig. 12). The mouth is subterminal with two pairs of long barbels (Table 2). The eyes are in the anterior half of the head and relatively big. The morphometric characters are summarised in Table 1.

The dorsal fin is long and strongly ossified and less than 15 % of the length of its last unbranched ray is flexible. Its last unbranched ray is as long as or longer than the head (Fig. 4). It usually has four unbranched and nine branched rays (Table 3). The anal fin usually has three unbranched and six or seven branched rays (Table 4). It does not reach the caudal fin origin.

Carasobarbus harterti has 31 to 38 scales in the lateral line (Table 5), usually 5.5 or 6.5 scales above the lateral line (Table 6), 4.5 to 6.5 scales below the lateral line (Table 7) and 13 to 17 scales around the least circumference of the caudal peduncle (Table 8). The scales are shown in Fig. 5.

The pharyngeal teeth count is -4.3.2 in four specimens examined. The pharyngeal teeth are hooked at their tips (Fig. 6).

Live specimens are silvery with an olive tinge and orange fins (Fig. 20). Ethanol-preserved specimens are yellow-brown, the back is darker than the belly and flanks.

The maximum length observed in the material examined is 250 mm SL.

Carasobarbus harterti differs from all congeners except Carasobarbus exulatus and Carasobarbus fritschii in having nine rather than 10 branched dorsal-fin rays. It differs from Carasobarbus exulatus in having 31 to 38 scales in the lateral line vs 26 to 32 and modally 16 scales around the least circumference of the caudal peduncle vs. 12. It differs from Carasobarbus fritschii in having a straight dorsal head profile and a last unbranched dorsal-fin ray that is strongly ossified and flexible for less than 15 % of its length vs. a convex dorsal head profile and a last unbranched dorsal-fin ray that is weakly ossified and flexible for more than 15 % of its length.

Distribution.

Carasobarbus harterti occurs in the rivers of the Oued Oum er Rbia and Tennsift drainage systems in Morocco (Fig. 18).

Habitats and biology.

Carasobarbus harterti is less common than Carasobarbus fritschii and inhabits only the lower and middle course of big rivers.

Conservation status.

The IUCN rates this species as "Vulnerable A2ace" ( Crivelli 2006d). The population has declined more than 30 % in the time from 1996 to 2006 due to urban, agricultural and industrial pollution ( Crivelli 2006d).

Discussion.

Carasobarbus harterti was described from Oued Oum er Rbia as Barbus harterti ( Günther 1901). Some authors placed this species in the genus Barbus subgenus Labeobarbus ( Boulenger 1919, Pellegrin 1921) while others continued using the genus Barbus ( Pellegrin 1919, 1939). Karaman (1971) synonymised it with Carasobarbus fritschii , but regarded it as a distinct subspecies. He incorrectly synonymised Barbus rothschildi , Barbus riggenbachi and Barbus paytonii with this subspecies and placed it in his newly erected genus Pseudotor . Subsequent authors did not accept Karaman’s proposal and continued using Barbus ( Fowler 1976, El Gharbi et al. 1993, Azeroual et al. 2000, Leggatt and Iwama 2003, Colli et al. 2009, Borkenhagen et al. 2011) or proposed using Labeobarbus ( Doadrio 1994, Tsigenopoulos et al. 2010). We transfer this species to the genus Carasobarbus , based on the possession of a smooth last unbranched dorsal-fin ray, nine branched dorsal-fin rays, six branched rays in the anal fin and shield-shaped scales with numerous parallel radii. Analysis of molecular genetic characters ( Durand et al. 2002, Tsigenopoulos et al. 2010, KB unpublished data) support this decision.