Carasobarbus, Karaman, 1971Carasobarbus apoensis (Banister & Clarke, 1977)

Carasobarbus View in CoL View Figure

Carasobarbus are a medium-sized group of barbels known from West Asia and Morocco. They are hexaploid and distinguished by large, shield-shaped scales with numerous parallel radii. The last unbranched dorsal ray is weakly to strongly ossified, without serrae. They have one or two pairs of barbels, 9–11½ branched dorsal rays, and 6½ branched anal rays. Carasobarbus kosswigi and C. sublimus were previously classified in a separate genus, Kosswigobarbus , which was recently synonymised with Carasobarbus . They are most species-rich in the Tigris, where six species are found. In the Arabian Peninsula, two species are known which have close relationships with Mesopotamian Carasobarbus . Carasobarbus are inhabitants of slow-flowing or stagnant waters, often with much vegetation, while former Kosswigobarbus inhabit large, free-flowing, deep rivers. Some species are large fish that are commercially exploited in many areas. As in many other barbels, their eggs are poisonous. Some people have reported feeling dizzy, having abdominal pain, vomiting, diarrhea, dry mouth, and faintness after eating a kebab made with about ¼ of an ovary of C. luteus .

Further reading. Karaman 1971 (description); Coad 2010a (toxic eggs); Borkenhagen & Krupp 2013 (description); Borkenhagen 2014 (phylogeny); Yang et al. 2015; Borkenhagen 2017 (phylogeny, in tribe Torini).

Keys to species of Carasobarbus in West Asia

Contributing author: Kai Borkenhagen (Büsum) contributed to the chapter on this genus.

Arabian Peninsula

1a - One pair of barbels;usually 10½ branched dorsal rays. ……………… C. apoensis

1b -Two pairs of barbels;usually 9½ branched dorsal rays. ……………… C. exulatus

Mediterranean and Persian Gulf basins

1a - Lower lip without median lobe. ………………2

1b - Lower lip with median lobe. ………………4

2a - Usually one pair of barbels; 25−30 total lateral-line scales. ……………… C. luteus

2b - Usually two pairs of barbels; 29−38 total lateral-line scales. ………………3

3a - Usually 12 circumpeduncular scales; usually 7−9 gill rakers;head length 24−29 % SL;adults larger than 100 mm SL head grey and caudal peduncle and caudal yellow. ……………… C. canis

3b - Usually 14−16 circumpeduncular scales; usually 9−12 gill rakers; head length 20−24 % SL; adults larger than 100 mm SL whole body golden or greenish grey. ……………… C. chantrei

4a - 24−29 total lateral-line scales. ……………… C. sublimus

4b - 32−44 total lateral-line scales..………………5

5a - 32−37 total lateral-line scales. ………………6

5b - 38−44 total lateral-line scales. ………………7

6a - 32−37 (mode 36) total lateral-line scales; head length 25−27 % SL; posterior barbel 13−20 % HL; snout length 36−44 % HL. ……………… C. kosswigi

6b - 32−34 (mode 33−34) total lateral-line scales; head length 20−24 % SL; posterior barbel 21−38 % HL; snout length 25−31 % HL. ……………… C. hajhosseini

7a - A prominent black blotch on posterior caudal peduncle in individuals smaller than 85 mm SL; head length 22−25 % SL; dorsal fin height 19−26 % SL; distance between pelvic and anal fin origins 24−25 % SL. ……………… C. doadrioi

7b - No black blotch on posterior caudal peduncle; head length 19−20 % SL;dorsal fin height 26−30 % SL; distance between pelvic and anal fin origins 26−28 % SL. ……………… C. saadatii Carasobarbus apoensis View in CoL View Figure View Figure

Common name. Arabian himri.

Diagnosis. Distinguished from Carasobarbus exulatus and superficially similar Arabibarbus arabicus in Arabian Peninsula by: ● one pair of barbels / ● usually 10½ branched dorsal rays / ○ 6½ anal rays. Size up to 288 mm SL.

Distribution View Figure . Saudi Arabia: Hijaz mountain range, in wadis, draining both inland and toward Red Sea.

Habitat. Mainly upper reaches of wadis with large seasonal variations in flow.

Biology. Lives up to 19 years, possibly longer in captivity. Spawns in early spring. Feeds on both aquatic and terrestrial invertebrates and plants.

Conservation status. EN; appears to be declining within its very small range.

Remarks. Very closely related to the Mesopotamian C. luteus . The two species may only have diverged in post-glacial times when a river flowing from the mountains of western Saudi Arabia to the southernmost Shatt al-Arab dried up.

Further reading. Banister & Clarke 1977 (description); Krupp 1983 (morphology, distribution); Borkenhagen & Krupp 2013 (description, distribution).