Glyptothorax granosus, Jiang & Ng & Yang & Chen, 2012

Jiang, Wansheng, Ng, Heok Hee, Yang, Junxing & Chen, Xiaoyong, 2012, A taxonomic review of the catfish identified as Glyptothorax zanaensis (Teleostei: Siluriformes: Sisoridae), with the descriptions of two new species, Zoological Journal of the Linnean Society 165 (2), pp. 363-389 : 377-380

GLYPTOTHORAX GRANOSUS SP. NOV. ( FIG. 9 )

Material examined: Holotype: KIZ 2000000586 (1), 61.8 mm SL; China: Yunnan, Nujiang Prefecture, Lushui County, Liuku Township , Manbu Village , Manbu River (a tributary of Nujiang), 25°52′44.4″N, 98°50′27.8″E, D. Catania, X. Y. Chen, Z. M. Chen, 22–24.vii.2000.

Paratypes: KIZ 2000000335 (one juvenile), 42.3 mm SL ; KIZ 2000000543 (1), 52.7 mm SL ; KIZ 2000000548 (1), 68.7 mm SL ; KIZ 2000000552 (1), 72.8 mm SL ; KIZ 2000000554–2000000555 (2), 48.6–65.9 mm SL ; KIZ 2000000557 (1), 69 mm SL ; KIZ 2000000560 (1), 68.7 mm SL ; KIZ 2000000574 (1), 61.6 mm SL ; KIZ 2000000576 (1), 72.6 mm SL ; KIZ 2000000584– 2000000585 (2), 61.8–67.2 mm SL; data as for holotype . CAS 222110 [2 alcohol preserved (alc.), 1 cleared and stained skeleton (c&s)], 47.0– 67.3 mm SL; China: Yunnan, Nujiang Prefecture, Lushui County, west bank of Nujiang ( Salween River ), 11.5 km south of Liuku on road to Shangjiang , 25°45′26.5″N, 98°51′56.6″E; C. J. Ferraris et al., 29.vii.2000 . CAS 223290 (4), 69.7–80.7 mm SL; China: Yunnan, Nujiang Prefecture, Lushui County, Mabu River , 3.9 km north of Liuku on road to Fugong , west bank of Nujiang ( Salween River ), and in Nujiang just south of Mabu River mouth, 25°52′44.4″N, 98°50′27.8″E; D. Catania et al., 22–24.vii.2000 . CAS 223324 (5), 69.7–77.2 mm SL; China: Yunnan, Nujiang Prefecture, Lushui County, west bank of Nujiang ( Salween River ), 52.2 km north of Liuku (and 1–2 km south of Chengan ) on road to Fugong , 26°14′32.6″N, 98°52′05.6″E; C. J. Ferraris et al., 28.vii.2000 . CAS 223338 (2), 71.2– 72.0 mm SL; China: Yunnan, Nujiang Prefecture, Lushui County, west bank of Nujiang ( Salween River ), 80 km north of Liuku on road to Fugong, 26°27′42.2′N, 98°53′52.2′E; C. J. Ferraris et al., 20.vii.2000 . CAS 223346 (2), 74.9–78.0 mm SL; China: Yunnan, Nujiang Prefecture, Gongshan County, Nujiang ( Salween River ) just below Yuange stream on east bank, c. 14 km south of bridge at Gongshan , 27°38′5.8″N, 98°43′51.2″E; C. J. Ferraris et al., 11.vii.2000 . CAS 226795 (5), 73.0– 95.7 mm SL; China: Yunnan, Nujiang Prefecture, Lushui County, Dashaba , 25°58′22.8″N, 98°50′31.5″E; local fishermen, 24.iv.2004 .

Additional nontype material: KIZ 2003006175 (1), 72.8 mm SL; KIZ 2003006179–2003006186 (8), 40.5– 81.9 mm SL; KIZ 2003006308–2003006310 (3), 50.4– 53.7 mm SL; KIZ 2003006312 (1), 83.8 mm SL; China: Yunnan, Nujiang Prefecture, Lushui County, Liuku Township, Yuejinqiao. KIZ 2003003112 (1), 84.7 mm SL; KIZ 2003003124 (1), 80.2 mm SL; KIZ 2003003126 (1), 72.4 mm SL; China: Yunnan, Nujiang Prefecture , Lushui County , Liuku Township , Xiangyangqiao. KIZ 2004014151 (1), 79.3 mm SL; China: Yunnan, Nujiang Prefecture , Lushui County , Liuku Township , Hongqiqiao. KIZ 05223–05226 (4), 97.4– 117.3 mm SL; China: Yunnan, Nujiang Prefecture , Lushui County , Daxingdi. KIZ 2000000539– 2000000540 (2), 54.5–78.4 mm SL; China: Yunnan, Nujiang Prefecture , Fugong County , Zilijia Township . KIZ 2000000521 (1), China: Yunnan, Nujiang Prefecture , Gongshan County , Puladi Township .

Diagnosis: Glyptothorax granosus sp. nov. can be distinguished from G. burmanicus in having the depressed area in the thoracic adhesive apparatus not wholly enclosed by ridges (vs. ridges of the thoracic adhesive apparatus enclosing an ovoid depressed region in the centre), a longer caudal peduncle (18.2– 23.7% SL vs. 14.8–18.7), and a shorter (23.1–26.0% SL vs. 27.6–30.8) and narrower head (16.6–19.5% SL vs. 20.0–25.7); from G. deqinensis in having more serrations on the posterior edge of the pectoral spine (nine to 13 vs. five to eight), narrower head (16.6–19.5 % SL vs. 19.5–21.7), and shorter inner and outer mandibular barbels (inner mandibular barbel: 25.7– 32.7% HL vs. 37.2–57.4; outer mandibular barbel: 39.8–51.4% HL vs. 59.2–85.7); from G. fucatus in having a uniformly coloured lateral surface of the body (vs. lateral surface of the body ventrally becoming paler immediately under lateral line), a triangular anterior nuchal plate element with (vs. without) saddle-shaped lateral expansions of the pterygiophores ( Fig. 6 ), a more slender body (depth at anus 12.9–16.5% SL vs. 15.5–21.1) and caudal peduncle (5.7–7.6% SL vs. 8.2–11.1), and smaller interorbital distance (20.4–28.8% HL vs. 28.1–34.0); and from G. longicauda in having fewer vertebrae (37–39 vs. 39–42). It differs from G. longinema in having a more slender caudal peduncle (5.7–7.6% SL vs. 7.1–10.6), narrower head (16.6–19.5% SL vs. 19.3–22.9), and a triangular anterior nuchal plate element with (vs. without) saddle-shaped lateral expansions of the pterygiophores ( Fig. 6 ), from G. longjiangensis in having small, conical tubercles (vs. large plaques bearing unculiferous ridges) on the dorsal surface of the head, from G. macromaculatus in having a triangular anterior nuchal plate element with (vs. without) saddle-shaped lateral expansions of the pterygiophores, distally expanded (vs. pointed) neural spines, without (vs. with) a diverging pattern of striae running along the edges of the median depression in the thoracic adhesive apparatus, and a shorter (23.1– 26.0% SL vs.27.4–34.4) and narrower head (16.6– 19.5% SL vs. 20.6–25.4), and from G. minimaculatus in lacking (vs. with) dark spots on the body and having a triangular anterior nuchal plate element with (vs. without) saddle-shaped lateral expansions of the pterygiophores. Glyptothorax granosus is distinguished from G. ngapang in having longer nasal barbel (22.8–34.0% HL vs. 14.1–23.5), from G. obliquimaculatus in lacking (vs. having) both the ridges of the thoracic adhesive apparatus extending onto the gular region and irregular dark blotches on the flanks and having a longer adipose-fin base (12.8–15.9% SL vs. 8.6–12.9), a more slender caudal peduncle (5.7–7.6% SL vs. 8.6–9.8), and a narrower head (16.6–19.5% SL vs. 19.1–24.0), from G. trilineatus in lacking (vs. having) a distinct pale midlateral line on the flank, and from G. zanaensis in having a longer thoracic adhesive apparatus (14.4–18.0% SL vs. 11.3–15.2), post-adipose distance (15.7–21.6% SL vs. 12.0–16.4), and caudal peduncle (18.2–23.7% SL vs. 14.8–18.9), shorter barbels (length of nasal barbel 22.8–34.0% HL vs. 33.9–52.9; length of maxillary barbel 76.8–98.5% HL vs. 103.8–161.0; length of inner mandibular barbel 25.7–32.7% HL vs. 34.5–57.7; length of outer mandibular barbel 39.8–51.4% HL vs. 58.8–87.9), a triangular anterior nuchal plate element with (vs. without) saddle-shaped lateral expansions of the pterygiophores ( Fig. 6 ), and without (vs. with) a diverging pattern of striae running along the edges of the median depression in the thoracic adhesive apparatus ( Fig. 5 ).

Description: Biometric data in Table 4.

Head depressed, body subcylindrical. Dorsal profile rising evenly from tip of snout to origin of dorsal fin, and then sloping gently ventrally from origin of dorsal fin to end of caudal peduncle. Ventral profile flat to anal-fin base, then sloping gently dorsally from analfin base to end of caudal peduncle. Anus and urogenital openings located at vertical through middle of adpressed pelvic fin. Skin tuberculate, with tubercles densely and uniformly arranged on sides of body and dorsal surface of neurocranium. Juveniles with tubercles prominently arranged in longitudinal rows on flanks. Lateral line complete and midlateral, laterosensory pores rimmed in beige, frequently with branches of laterosensory canal system visibly radiating from it. Anterior nuchal plate element triangular, with saddle-shaped lateral extensions and extensive contact with posterior nuchal plate element. Vertebrae 16 + 21 = 37 (2), 16 + 22 = 38 (10), 16 + 23 = 39 (1), or 17 + 22 = 39 (1).

Head depressed and broad, triangular when viewed laterally. Snout acutely convex when viewed from above. Anterior and posterior nares separated only by base of nasal barbel. Eyes small and ovoid, horizontal axis longest, located on dorsal half of head. Gill openings broad, extending from directly beneath posttemporal to isthmus.

Barbels in four pairs. Maxillary barbel thick, extending to base of last pectoral-fin ray. Nasal barbel slender, extending to anterior orbital margin. Inner mandibular barbel extending to anterior edge of thoracic adhesive apparatus. Outer mandibular barbel originating posterolateral of inner mandibular barbel, extending to base of pectoral-fin spine.

Mouth inferior, premaxillary tooth band partially exposed when mouth closed. Oral teeth small and villiform, in irregular rows on all tooth-bearing surfaces. Premaxillary teeth in single crescentic-shaped band. Dentary teeth in two patches separated by narrow gap at midline. Palate edentate.

Dorsal fin equidistant from snout tip to adipose-fin origin, with I,6 rays; dorsal margin truncate; anterior margin of spine smooth, posterior margin with weak serrations. Adipose fin straight anteriorly and angular posteriorly. Caudal fin deeply forked, lobes almost equal, with i,7,7,i (8) or i,7,8,i (16) principal rays. Procurrent rays symmetrical, extending only slightly anterior to fin base and consisting of five to seven rays. Anal-fin origin slightly anterior to vertical through adipose-fin origin. Anal fin with straight anterior margin and straight or slightly concave posterior margin; with ii,9 (18) or ii,10 (6) rays. Pectoral fin with I,9 (4), I,10 (18), or I,11 (2) rays; posterior fin margin straight; anterior spine margin smooth, posterior spine margin with nine to 13 serrations. Pelvicfin origin at vertical through posterior end of dorsalfin base. Pelvic fin with slightly convex margin and i,5 rays; tip of adpressed fin not reaching anal-fin origin.

Thoracic adhesive apparatus present, consisting of narrow skin ridges (striae) in an elongate oval field extending from isthmus to end of pectoral-fin base and with median depression present on posterior onethird to half. Striae orientated anterodistally, radiating from median depression.

Coloration: In 75% ethanol: dorsal and lateral surfaces of head and body brown. Ventral surface of head and body greyish beige. Dorsal surface of head with distinct pale patches; nuchal plate elements distinctly pale. A faint, thin, light grey mid-dorsal stripe outlining distal tips of neural spines extending posterior to base of last dorsal-fin ray to adipose-fin origin. Laterosensory pores along lateral line rimmed in beige tubercles, imparting appearance of a narrow pale line; branches of canals sometimes imparting a spine-like form, or herringbone pattern. Dorsal and anal fins, and dorsal surfaces of pectoral and pelvic fins with dark brown bases and bands on middle third, rest of fins yellow to hyaline. Adipose fin yellow at base and distally, remainder of fin dark brown. Caudal fin brown, with tips of lobes hyaline. Maxillary and nasal barbels brown dorsally, light yellow ventrally.

Distribution: Known from the upper Salween River (Nujiang) drainage ( Fig. 7 )

Etymology: The specific epithet granosus is Latin, meaning ‘full of grain’, in allusion to the appearance suggested by the prominent tubercles in the juveniles of this species. Used as an adjective.

Figures

Figure 5. Thoracic adhesive apparatus of: A, Glyptothorax zanaensis, KIZ 2000000534, 60.1 mm SL; B, Glyptothorax longinema, KIZ 740197, 67 mm SL; C, Glyptothorax fucatus sp. nov., KIZ 20050410936, 72.9 mm SL, D, Glyptothorax granosus sp. nov., KIZ 2000000534, 61.8 mm SL.

Figure 6. Dorsal view of nuchal plate elements of: A, Glyptothorax zanaensis and Glyptothorax longinema; B, Glyp- tothorax fucatus sp. nov.; and C, Glyptothorax granosus sp. nov.

Figure 7. Distributions of the four species studied; -, Glyptothorax zanaensis; ·, Glyptothorax granosus sp. nov.;, Glyptothorax longinema; •, Glyptothorax fucatus sp. nov.

Figure 9. Glyptothorax granosus, KIZ 2000000534, holotype, 61.8 mm SL, China: Manbu River; A, dorsal view; B, lateral view; C, ventral view. Scale bar = 10 mm.