Pseudecheneis stenura Ng, 2006

Zhou, Wei, Li, Xu & Yang, Ying, 2008, A Review Of The Catfish Genus Pseudecheneis (Siluriformes: Sisoridae) From China, With The Description Of Four New Species From Yunnan, Raffles Bulletin of Zoology 56 (1), pp. 107-124 : 119-120

Pseudecheneis stenura Ng, 2006

( Fig. 14 )

Pseudecheneis sulcatus – Chu, 1982: 431 (in part specimens from Irrawaddy); Chu, Mo & Kuang, 1990: 196–197, Fig. 196 (in part specimens from Irrawaddy) ; Chu & Mo 1999: 153–154, Fig. 98 (in part specimens from Irrawaddy) .

Pseudecheneis stenura Ng, 2006a: 57–61 , Fig. 5 (Longchuanjiang); Thomson & Page, 2006: 60 (Irrawaddy drainage, China).

Material examined. – KIZ 9811088 , 9811023 , 2 ex., topotypes collected with the holotype, 85.3–93.9 mm SL, Longchuanjiang at Lianmengjie bridge, Tengchong County, Yunnan Province ; SWFC 0502001–012, 12 ex., 73.8–90.5 mm SL, Sanchahe , Lianghe County, Yunnan Province .

Morphometric data as in Table 3.

Diagnosis. – Pseudecheneis stenura is distinguished from P. sulcata in having longer pelvic fin, reaching base of the first anal fin ray (vs. not reaching), and from P. crassicauda in having longer pectoral fin, reaching origin of pelvic fin (vs. not reaching). Further distinguished from P. serracula in having a shorter adipose fin base (length of adipose fin base 125–166.7% in length of anal fin base vs. larger than 200%), and from P. sympelvica in having separate pelvic fins (vs. fused). Further distinguished from other congeners except P. gracilis in having a deeper forked caudal fin, shortest ray of caudal fin circa 50% of longest ray (vs. 75%). Differs from P. gracilis in having two ovoid yellow patches on dorsal fin origin (vs. a saddle patch) ( Fig. 5B, C ); length of head longer, head length 20.1–23.7% SL (vs. 14.9–18.6), postorbital head length 8.5–11.4% in head length (vs. 4.5– 5.9), body depth 67.1–88.5% in head length (vs. 73.9– 112.2%). It differs from P. paviei in having 15-19 transverse ridges (laminae) of thoracic apparatus (vs. 9–13). Premaxillary tooth band semicircular and two or four teeth along its outer edge ( Fig. 2A ). Body covered with dense, rounded tubercles distributed irregularly, not uniformly ( Fig. 4A ). Tubercles decreasing in density gradually from occipital to caudal peduncle which almost no tubercles. Vertebrae 19+20=39.

Distribution. – This species is found in the Longchuanjiang, part of the Irrawaddy River drainage ( Fig. 11 ).

Figures

Fig.14. Pseudecheneis stenura, KIZ 9811088, 93.9 mm SL; China: Longchuanjiang (a branch of Irrawaddy River) drainage. Dorsal, lateral and ventral views.

Fig. 5. Patch or spots at dorsal fin origin: A, spots connected as a saddle patch (Pseudecheneis brachyurus, SWFC 200103294, holotype, 122 mm SL); B, spots connected as a saddle patch (P. gracilis, SWFC 200102125, paratype, 168 mm SL); C, spots isolated as two ovoid spots (P. stenura, SWFC 0502001, 90.5 mm SL).

Fig. 2. Premaxillary and mandibular tooth band. A, ventral view of semicircular premaxillary tooth band and four teeth along its outer edge (Pseudecheneis gracilis, SWFC 200102148, paratype, 68 mm SL, DS); B, dorsal view of crescent mandibular tooth band (P. gracilis, SWFC 200102148, paratype, 68 mm SL, DS); C, ventral view of semicircular premaxillary tooth band and eight teeth along its outer edge (P. paviei, SWFC 0005084, 62 mm SL, DS).

Fig. 4. Tubercles at dorsal of head: A, rounded tubercles (Pseudecheneis stenura, SWFC 0502004, 78.6 mm SL); B, some longitudinal tubercles among rounded tubercles (P. sulcatoides, SWFC 200005030, 75 mm SL).

Fig. 11. Map showing distribution of Pseudecheneis paucipunctatus, P. paviei, P. stenura, P. sulcata and P. sulcatoides.