A small fish (D. lamta), extremely abundant in almost all the mountain streams from Abyssinia and Syria to Assam.
Capoëta.—Scales small, of moderate or large size. Dorsal fin with or without a strong osseous ray, with not more than nine branched rays. Snout rounded, with the mouth transverse and at its lower side; each mandible angularly bent inwards in front, the anterior mandibular edge being nearly straight, sharpish, and covered with a horny brown layer. No lower labial fold. Barbels two (rarely four), or entirely absent. Anal scales not conspicuously enlarged. Pharyngeal teeth compressed, truncated, 5 or 4. 3. 2–2. 3. 4 or 5.
Characteristic of the fauna of Western Asia; one species from Abyssinia. Of the fifteen species known C. damascina deserves to be specially mentioned, being abundant in the Jordan and other rivers of Syria and Asia Minor.
Barbus.—Scales of small, moderate, or large size. Dorsal fin generally with the (third) longest simple ray ossified, enlarged, and frequently serrated; never, or only exceptionally, with more than nine branched rays, commencing opposite or nearly opposite to the root of the ventral fin. Eyes without adipose eyelid. Anal fin frequently very high. Mouth arched, without inner folds, inferior or anterior; lips without horny covering. Barbels short, four, two, or none. Anal scales not enlarged. Pharyngeal teeth 5. 4 or 3. 3 or 2.-2 or 3. 3 or 4. 5. Snout but rarely with tubercles or pore-like grooves.
No other genus of Cyprinoids is composed of so many species as the genus of “Barbels,” about 200 being known from the tropical and temperate parts of the Old World; it is not represented in the New World. Although the species differ much from each other in the form of the body, number of barbels, size of the scales, strength of the first dorsal ray or spine, etc., the transition between the extreme forms is so perfect that no further generic subdivision should be attempted. Some attain a length of six feet, whilst others never exceed a length of two inches. The most noteworthy are the large Barbels of the Tigris (B. subquincunciatus, B. esocinus, B. scheich, B. sharpeyi); the common Barbel of Central Europe and Great Britain (B. vulgaris); the “Bynni” of the Nile (B. bynni); B. canis from the Jordan; the “Mahaseer” of the mountain streams of India (B. mosal), probably the largest of all species, the scales of which are sometimes as large as the palm of a hand. The small, large-scaled species are especially numerous in the East Indies and the fresh waters of Tropical Africa.
Thynnichthys.—Scales small. Dorsal fin without an osseous ray, with not more than nine branched rays, commencing nearly opposite the ventrals. Head large, strongly compressed; eye without well-developed adipose membrane, in the middle of the depth of the head. Snout with the integuments very thin; there is no upper lip, and the lower jaw has a thin labial fold on the sides only. Mouth anterior and lateral; barbels none. Gill-rakers none; laminæ branchiales long, half as long as the post-orbital portion of the head; pseudobranchiæ none. Pharyngeal teeth lamelliform, with flat oblong crown, 5. 3 or 4. 2–2. 4 or 3. 5, the teeth of the three series being wedged into one another.
Three species from the East Indies.
Oreinus.—Scales very small. Dorsal fin with a strong osseous serrated ray, opposite to the ventrals. Snout rounded, with the mouth transverse, and at its lower side; mandibles broad, short, and flat, loosely joined together; margin of the jaw covered with a thick horny layer; a broad fringe-like lower lip, with free posterior margin. Barbels four. Vent and anal fin in a sheath, covered with enlarged tiled scales. Pharyngeal teeth pointed, more or less hooked, 5. 3. 2–2. 3. 5.
Three species from mountain streams of the Himalayas.
Schizothorax.—Hill-barbels, with the same singular sheath on each side of the vent, as in the preceding genus; but they differ in having the mouth normally formed, with mandibles of the usual length and width.