|
| (1) | (i) Snout with proboscis | (2) |
| (ii) Snout without proboscis | (7) |
|
| (2) | (i) Proboscis well-developed | (3) |
| (ii) Proboscis incipient, represented by a truncate area in front of the nostrils | gravelyi |
|
| (3) | (i) Proboscis bilobed with one large | bispinosa |
| (ii) Proboscis unilobed or quadrate | (4) |
|
| (4) | (i) Vent to anal distance more than 45% of pelvic to anal-fin distance | elongata |
| (ii) Vent to anal distance less than 40% of pelvic to anal-fin distance | (5) |
|
| (5) | (i) Simple dorsal fin rays two | litanensis |
| (ii) Simple dorsal fin rays four | (6) |
|
| (6) | (i) Lateral line scales 34; anus to anal distance 32.1–39.2% of pelvic to anal distance | rotundinasus |
| (ii) Lateral line scales 36-37; anus to anal distance 22.8–28.3% of pelvic to anal distance | qiaojiensis |
|
| (7) | (i) Caudal fin with W-shaped black mark | (8) |
| (ii) Caudal fin without W-shaped black mark | (9) |
|
| (8) | (i) Caudal fin forked | nambulica |
| (ii) Caudal fin slightly emarginated | (10) |
|
| (9) | (i) Rostral lobe present | poecilura |
| (ii) Rostral lobe absent | (11) |
|
| (10) | (i) Snout without tubercles | abhoyai |
| (ii) Snout with tubercles | (14) |
|
| (11) | (i) Snout without barbels | imberbis |
| (ii) Snout with barbels | (12) |
|
| (12) | (i) Lateral line scales 30-31 | spilota |
| (ii) Lateral line scales more than 37-38 | (13) |
|
| (13) | (i) Simple dorsal fin rays two; depth of body 17.0–17.6% SL | compressus |
| (ii) Simple dorsal fin rays four; depth of body 20.4–24.6% SL | tengchongensis |
|
| (14) | (i) Rostral lobe absent, chest, and abdomen naked | Paralissorhynchus |
| (ii) Rostral lobe present, chest, and abdomen scaled | namyaensis |
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