Carasobarbus canis (Valenciennes in Cuvier and Valenciennes 1842)

Borkenhagen, Kai & Krupp, Friedhelm, 2013, Taxonomic revision of the genus Carasobarbus Karaman, 1971 (Actinopterygii, Cyprinidae), ZooKeys 339, pp. 1-53 : 8-13

Carasobarbus canis (Valenciennes in Cuvier and Valenciennes 1842)

Barbus canis Valenciennes in Cuvier and Valenciennes 1842: 186.

Barbus beddomii Günther 1868: 110.

Material.

Type material. Lectotype of Barbus canis : MNHN 0000-1413, 1, Jordan River [31°46'N, 35°33'E], Bové, 1833 (designated by Krupp and Schneider 1989).

Paralectotype of Barbus canis : MNHN 0000-3944, 1, same data as lectotype.

Holotype of Barbus beddomii : BMNH 1863.11.3:5, 1, Lake Tiberias [32°48'N, 35°35'E], T. W. Beddome.

Non-type material. Jordan River Drainage. SMF 14075, 2, Lake Tiberias (32°48'N, 35°35'E), M. Goren, 15 Mar 1968. - SMF 33134, 16, Syria, Nahr al Yarmūk near Jallayn (32°44'21"N, 35°58'56"E), N. Alwan et al., 16 Oct 2008. - SMF 24464, 1, Jordan, Nahr al Yarmūk near Maqārin (32°43'N, 35°53'E), F. Krupp and W. Schneider, 23 Sep 1985. - SMF 30175, 11, Syria, Lake Muzayrīb [32°42'40"N, 36°1'39"E], F. Krupp and W. Schneider, 12 Apr 1989. - SMF 33135, 17, Jordan, Wadi al-'Arab near the dam (32°37'6"N, 35°37'46"E), N. Alwan et al., 25 Oct 2008. - SMF 17123, 16, Wādī al Yābis (32°24'N, 35°36'E), F. Krupp and W. Schneider, 23 Jul 1980. - ZMH H 2343, 3, Jordan, Wādī Kufrinjah (32°16'25"N, 35°33'42"E). - SMF 24344, 3; SMF 24345, 17, Jordan, Nahr az Zarqā’ (32°12'N, 35°50'E), F. Krupp and W. Schneider, 22 Jul 1980. - SMF 24339, 3, Jordan, Nahr az Zarqā’ (32°10'N, 35°37'E), F. Krupp and W. Schneider, 21 Jul 1980. - SMF 24340, 1, Jordan, Nahr az Zarqā’ near Sadd al Malik Talal (32°10'N, 35°49'E), F. Krupp and W. Schneider, 22 Jul 1980. - SMF 24331, 7; SMF 24346, 3, Jordan, Nahr al Yarmūk channel (32°08'N, 35°36'E), F. Krupp and W. Schneider, 21 Jul 1980. - NMW 53961, 1, Jordan River [31°46'N, 35°33'E], Cenoni, Dec 1898.

Azraq Oasis. BMNH 1956.2.24:15-16, 2; BMNH 1965.11.24:2, 1, Jordan, wetland near Azraq ash Shīshān [31°50'N, 36°49'E].

Coastal rivers of the Mediterranean Sea. BMNH 1949.9.16:124, 1, Israel, Naẖal Na‘aman [32°54'42"N, 35°4'50"E]. - NMW 22367, 1, Israel, Naẖal Na‘aman [32°54'42"N, 35°4'50"E], H. Steinitz, 21 Oct 1955. - SMF 9229, 1, Israel, Naẖal Yarqon [32°6'7"N, 34°46'32"E].

Diagnosis.

Two pairs of barbels, 29 to 35 scales in the lateral line and usually 12 scales around the least circumference of the caudal peduncle, last unbranched ray of dorsal fin shorter than head.

Description.

The body is low. A nuchal hump is present in adults but absent in juveniles. The largest body depth is at the origin of the dorsal fin. The head is long, rather low and fairly narrow with straight dorsal and convex ventral profile (Figs 8, 9). The head length approximately equals the body depth. The mouth is terminal or slightly subterminal. Two pairs of barbels are present (Table 2). The lips are smooth and thin (Fig. 3). The eyes are at the end of the anterior half of the head. The morphometric characters are summarised in Table 1.

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

There are 29 to 35 scales in the lateral line (Table 5), usually 4.5 or 5.5 scales above the lateral line (Table 6), usually 4.5 scales below the lateral line (Table 7) and usually 12 scales around the least circumference of the caudal peduncle (Table 8). The scales are shown in Fig. 5.

The pharyngeal teeth count is 2.3.5-5.3.2 in 23 specimens, 2.3.3-5.3.2 in one specimen, 2.3.5- in one specimen and -5.3.2 in one specimen. The pharyngeal teeth are hooked at their tips (Fig. 6).

Live specimens are silvery to bronze coloured. The posterior third of the body and the fins are distinctly yellow in many specimens (Fig. 9). Ethanol-preserved specimens are brownish yellow and the back is only slightly darker than the rest of the body (Fig. 8). The fins are brownish yellow. Juveniles have a dark lateral spot on the caudal peduncle.

Carasobarbus canis differs from Carasobarbus apoensis and Carasobarbus luteus in having two pairs of barbels vs. one, from Carasobarbus kosswigi and Carasobarbus sublimus in having a crescent-shaped lower lip without median lobe vs. a spatulate lower lip with median lobe, from Carasobarbus exulatus in modally having 10 branched dorsal-fin rays vs. nine and from Carasobarbus chantrei , Carasobarbus fritschii and Carasobarbus harterti in modally having 10 scales around the least circumference of the caudal peduncle vs. 14 or 16.

Distribution.

Carasobarbus canis occurs in the Jordan River system (Fig. 7). There are only few records from coastal rivers of the Mediterranean Sea (Naẖal Na‘aman and Naẖal Yarqon). A recent treatment of the inland water fish communities of Israel does not report Carasobarbus canis from coastal rivers ( Goren and Ortal 1999). The population in the Azraq Oasis was introduced by humans ( Krupp and Schneider 1989). Since the year 2000 this species was not found in Azraq ( Hamidan 2004) and the population may have disappeared due to drought. Records from the Tigris-Euphrates system ( Banister 1980) are based on misidentifications.

Habitats and biology.

Carasobarbus canis inhabits a wide range of rivers, lakes and ponds ( Goren 1974) with clean as well as polluted water ( Mir 1990). Adults reach a length of about 40 cm (max. 66 cm) and are of economic importance locally (annual catch in Israel 1970-85 about 50 t, Fishelson et al. 1996). It feeds on fish, aquatic invertebrates, algae and detritus ( Ben-Tuvia 1978, Spataru and Gophen 1985, Krupp and Schneider 1989). The relative proportion of fish in the diet increases with body length and small cyprinids of the genus Mirogrex are their most important prey ( Spataru and Gophen 1985). The spawning grounds are (among others) at the shore of Lake Tiberias where the spawning occurs in shallow water over hard bottom in December and January, one month after the start of the rainy season ( Fishelson et al. 1996). The sticky eggs attach to the substrate. Winter spawning is seen as evidence for an origin in cooler areas ( Fishelson et al. 1996).

Conservation status.

Catches in Lake Tiberias are declining ( Fishelson et al. 1996). The species is rated Least Concern by the IUCN ( Crivelli 2006a). The population in Lake Tiberias does not face serious threats; the riverine populations are declining and threatened by pollution, water extraction, drought and fragmentation due to damming ( Crivelli 2006a).

Remarks and discussion.

Carasobarbus canis was described from the Jordan River as a member of the genus Barbus ( Cuvier and Valenciennes 1842). Later it was assigned to Luciobarbus ( Heckel 1843), and Labeobarbus ( Günther 1864). Subsequently it was transfered back to Barbus ( Günther 1868) and then placed in Tor ( Karaman 1971, Banarescu 1977), Barbus ( Banister and Clarke 1977, Krupp 1983a), Carasobarbus ( Ekmekçi and Banarescu 1998) and Barbus subgenus Carasobarbus ( Tsigenopoulos et al. 2010). MNHN 0000-1413 was designated as lectotype ( Krupp and Schneider 1989). Barbus beddomii is considered to be a junior synonym of Carasobarbus canis ( Berg 1949, Karaman 1971, Krupp and Schneider 1989).