Carasobarbus apoensis (Banister & Clarke, 1977)

Borkenhagen, Kai & Krupp, Friedhelm, 2013, Taxonomic revision of the genus Carasobarbus Karaman, 1971 (Actinopterygii, Cyprinidae), ZooKeys 339, pp. 1-53 : 5-8

Carasobarbus apoensis (Banister & Clarke, 1977)

Barbus apoensis Banister and Clarke 1977: 113.

Material.

Type material. Holotype of Barbus apoensis : BMNH 1976.4.7:166, Saudi Arabia, permanent stream near Khamīs Mushayt (18°17'N, 42°34'E), F. Tippler, 12 Dec 1968.

Paratypes of Barbus apoensis : BMNH 1976.4.7:167-171, 5, same data as holotype. - BMNH 1976.4.7:172-175, 4, Saudi Arabia, upper Wādī Turabah near Aţ Ţā’if (22°56'N, 40°54'E), G. Popov. - BMNH 1971.2.11:1-2, 2, Saudi Arabia, intermittent watercourse in Wādī Adamah (19°53'N, 41°57'E), J. P. Mandaville, 27 Oct 1969.

Non-type material. Endorheic darinages. BMNH 1980.7.1:15, 1, Saudi Arabia, Wādī Habayaba between Aţ Ţā’if and Ash Shafā [N21°11', E 40°24'], A. Farag, 1980. - SMF 30167, 3; SMF 30170, 10 Saudi Arabia, Wādī Būwah (20°45'N, 41°8'E), F. Krupp and W. Schneider, 21 Mar 1990. - SMF 30169, 6; SMF 33147, 4, Saudi Arabia, Wādī Būwah (20°44'N, 41°7'E), F. Krupp and W. Schneider, 21 Mar 1990. - SMF 30168, 6; SMF 30171, 9, Saudi Arabia, Wādī Turabah (20°32'N, 41°17'E), F. Krupp and W. Schneider, 20 Mar 1990.

Streams draining towards the Red Sea. CMNFI 87-0135, 1; CMNFI 87-0137, 4, Saudi Arabia, Wādī Hadīyah (25°34'N, 38°41'E). - SMF 33149, 1, Saudi Arabia, Wādī Ḩaqqaq (22°49'N, 39°22'E), W. Büttiker, 5/6 May 1983. - SMF 33148, 2, Saudi Arabia, Wādī 'Ilyab (20°5'N, 40°54'E), H. Felemban and J. Gasparetti, 28 Oct 1983. - SMF 33539, 3, Saudi Arabia, Wādī 'Ilyab (20°7'N, 40°57E), W. Büttiker, 10−11 Nov 1983.

Unknown drainage system. SMF 33146, 4, Saudi Arabia, Al Ḩijāz, W. Büttiker.

Diagnosis.

One pair of barbels, usually 10 branched rays in the dorsal fin, 27 to 32 scales in the lateral line, usually 12 scales around the least circumference of the caudal peduncle, last unbranched ray of dorsal fin shorter than head.

Description.

The body depth is comparatively low and a nuchal hump is present in adults but not developed in juveniles. The height of the caudal peduncle is relatively low (Table 1). The dorsal and ventral fins are usually positioned behind the middle of the body. The head is elongate with a straight or slightly concave dorsal profile. The ventral profile of the head is slightly convex. (Figs 1, 2). The head length is about equal to the body depth. The mouth is broad and terminal or slightly sub-terminal with one pair of barbels (Fig. 3, Table 2). Only one out of 65 specimens had two pairs of barbels and in one specimen a single anterior barbel was present. The eyes are in the anterior half of the head and slightly protuberant. The morphometric characters are summarised in Table 1.

The dorsal fin and its base are rather short. It usually has four unbranched and 10 branched rays (Table 3). The last unbranched ray is considerably shorter than the head (Fig. 4), weakly ossified, and its distal part is flexible. The anal fin has three unbranched and six branched rays (Table 4). Pectoral and ventral fins are relatively short (Table 1).

Carasobarbus apoensis has 27 to 32 scales in the lateral line (Table 5), usually 4.5 scales above the lateral line (Table 6), 3.5 or 4.5 scales below the lateral line (Table 7) and 12 scales around the least circumference of the caudal peduncle (Table 8). The scales are shown in Fig. 5.

The pharyngeal teeth count is 2.3.5- in 12 specimens, -5.3.2 in two specimens and 1.3.5- in one specimen. The pharyngeal teeth are hooked at their tips (Fig. 6).

Live colouration is golden with olive fins. The upper side is darker than the belly (Fig. 2). In ethanol-preserved specimens the upper side is dark, the belly yellow and the fins are grey or yellow (Fig. 1). Juveniles have a dark lateral spot on the caudal peduncle.

The maximum length observed in the material examined is 288 mm SL.

Carasobarbus apoensis differs from all congeners, except Carasobarbus luteus , by having one rather than two pairs of barbels. For a comparison with Carasobarbus luteus populations see below.

Distribution. Carasobarbus apoensis occurs in the Al Ḩijāz mountain range in wadis draining either inland or towards the Red Sea (Fig. 7). It is endemic to Saudi Arabia.

Habitats and biology.

This species inhabits the upper courses of wadis, which are characterised by strong seasonal fluctuations in water levels, temperature and other physiochemical parameters.

Conservation status.

Carasobarbus apoensis is rated Least Concern and still occurs in large numbers, but abstraction of large specimens by recreational fishing, water abstraction and habitat loss might become problematic for this species ( BCEAW 2002).

Remarks and discussion.

Carasobarbus apoensis was originally described from Khamīs Mushayt, Wādī Turabah and Wādī Adamah as a member of the genus Barbus ( Banister and Clarke 1977). It was later transferred to the genus Carasobarbus ( Ekmek-çi and Banarescu 1998). Alkahem and Behnke (1983) reported an unknown Barbus and tentatively considered these specimens to be atypical Carasobarbus apoensis . We did not find any evidence of an undescribed Carasobarbus species that occurs sympatrically with Carasobarbus apoensis , thus we agree with their conclusion.

Carasobarbus apoensis is very closely related to Carasobarbus luteus (KB unpublished data).