The Glyptothorax of Sundaland: a revisionary study (Teleostei: Sisoridae) Ng, Heok Hee Kottelat, Maurice Zootaxa 2016 4188 1 1 92 [151,389,2004,2030] Actinopterygii Sisoridae Glyptothorax Animalia Siluriformes 48 49 Chordata species pictus sp. nov.     Typematerial. Holotype:  MZB17218, 54.2mm SL; Borneo: Kalimantan Tengah, Sungai Teweh above Desa Lampeong II, Barito Riverdrainage; A. Tjakrawidjaja& A. Mun’im,  2 October 1995.   Paratypes: BORNEO: ZRC53523 (1), 59.9 mmSL; Kalimantan Tengah: stream at km 57 logging road at buffer zone of Bukit Raya-Bukit Baka National Park, Katingan Riverdrainage, 0°4'4"S 112°16'57"E; H. H. Tan et al.,  11–12 August 2007.   MZB6995(70), 17.8–30.8 mmSL; Kalimantan Tengah, Kecamatan Laung Tuhup, Sungai Laungat Desa Maruwei, Barito Riverdrainage; A. Tjakrawidjaja, D. Siebert& O. Crimmen,  15–18 July 1992.  ZRC53522 (1), 76.1 mmSL; Kalimantan Tengah: Sungai Baha’e, km 64 on logging road at buffer zone of Bukit Raya-Bukit Baka National Park, Katingan Riverdrainage, 0°47'35.6"S 112°19'13.2"E; H. H. Tan et al.,  12–13 August 2007.  ZRC53521 (2), 45.9–49.2 mmSL; Kalimantan Tengah: stream at buffer zone of Bukit Raya-Bukit Baka National Park, Katingan Riverdrainage, 0°44'55"S 112°15'51"E; H. H. Tan et al.,  12–13 August 2007.  BMNH1998.9.30.20–34 (15), 27.8–57.2 mmSL; Kalimantan Tengah, Sungai Kiasat Desa Tambaba, Barito Riverdrainage; A. Tjakradwidjaja& A. Mun’im,  2 October 1995.  BMNH1998.9.30.282–310 (29), 23.6–54.3 mmSL; data as for holotype.   MZB1302(1), 68.0 mm SL; Kalimantan Selatan: Batang Alaiat Datar Alai, Barito Riverdrainage; M. A. Rifai,  22 October 1972.   MZB1306(2), 59.8–79.6 mmSL; same locality; M. A. Rifai,  25 October 1972.   Diagnosis.  Glyptothorax pictusdiffers from all Sundaic congeners except for  G. decussatusin having a color pattern consisting of a brown or brownish gray body with prominent dark vertical bars at the level of the adiposefin base and the base of the caudal fin (vs. without distinct vertical markings on body). It is distinguished from  G. decussatusin lacking (vs. having) anteromedial striae in the thoracic adhesive apparatus and the pelvic fins not reaching (vs. reaching) the base of the first anal-fin ray when adpressed. The only Sundaic congeners with a vaguely similar color pattern are  G. exodonand  G. platypogonides( Figs. 10and 31), but G. p i c t u sdiffers from  G. exodonin having the premaxillary toothband approximately half (vs. almost entirely) exposed when the mouth is closed and a shorter dorsal-to-adipose distance (14.7–21.4% SL vs. 21.9–26.3), and from  G. platypogonidesin having a deeper body (depth at anus 15.4–20.2% SL vs. 12.1–14.8), a deeper caudal peduncle (8.4–10.9% SL vs. 6.5–7.9) and a longer adipose-fin base (13.6–18.9% SL vs. 10.7–13.7). The following unique combination of characters further distinguishes  G. pictusfrom Sundaic congeners: anteromedial striae in thoracic adhesive apparatus absent; pectoral-fin spine length 17.3–22.9% SL; dorsal-fin spine length 15.4–20.9% SL; margin of dorsal fin concave; straight dorsoposterior margin of adipose fin; caudal peduncle depth 8.4–10.9% SL; caudal fin without prominent dark longitudinal stripes running through each lobe; and absence of prominent pale midlateral stripe on body.   Description.Morphometric data in Table 10. Head depressed; body subcylindrical. Dorsal profile rising evenly from tip of snout to origin of dorsal fin, then sloping gently ventrally from origin of dorsal fin to end of caudal peduncle. Ventral profile straight to anal-fin base, then sloping gently dorsally from anal-fin base to end of caudal peduncle. Anus and urogenital openings located at vertical through middle of adpressed pelvic fin. Skin tuberculate, with tubercles of even size on sides of body. Lateral line complete and midlateral. Vertebrae 15+17=32 (1), 17+15=32 (1), 16+17=33 (5), 17+16=33 (4), 16+18=34 (3), 17+17=34* (26), 18+16=34 (3) or 18+17=35 (1). Head depressed and broad, triangular when viewed laterally. Snout prominent. Anterior and posterior nares large and separated only by base of nasal barbel. Gill opening broad, extending from ventral margin of posttemporal to isthmus. First branchial arch with 2+6 (2), 2+7* (11), 3+6 (2), 2+8 (2) or 3+7 (3) rakers. Bony elements of dorsal surface of head covered with thick, tuberculate skin. Eye ovoid, horizontal axis longest; located entirely in dorsal half of head. Barbels in four pairs. Maxillary barbel long and slender, extending to middle of pectoral-fin base. Nasal barbel slender, extending to midway between its base and anterior orbital margin. Inner mandibular-barbel extending to midway between its base and that of pectoral spine. Outer mandibular barbel extending to two-thirds of distance between its base and that of pectoral spine. Mouth inferior, premaxillary tooth band partially (approximately half) exposed when mouth is closed. Oral teeth small and villiform, in irregular rows on all tooth-bearing surfaces. Premaxillary teeth appearing in single broad semilunate band. Dentary teeth in a single crescentic band, consisting of two separate halves tightly bound at midline.   TABLE 10.Morphometric data for  Glyptothorax pictus(n=24).    Holotype MZB 17218 Range Mean±SD  Standard length (mm) %SL 54.2 45.9–76.1  Predorsal length Preanal length Prepelvic length 39.3 68.3 51.7 35.1–40.4 64.5–71.7 48.4–53.5 38.2±1.63 68.2±1.75 51.4±1.43  Prepectoral length Length of dorsal-fin base Dorsal-fin spine length 23.4 13.8 17.9 19.5–25.8 12.7–16.5 15.4–20.9 23.1±1.95 14.4±1.00 17.6±1.69  Length of anal-fin base Pelvic-fin length Pectoral-fin length 15.5 15.3 22.9 13.4–18.0 13.7–17.5 21.9–27.4 15.5±1.12 15.9±1.01 24.5±1.62  Pectoral-fin spine length Caudal-fin length Length of adipose-fin base 19.7 28.4 16.2 17.3–22.9 24.8–30.6 13.6–18.9 20.1±1.77 27.6±1.51 15.4±1.25  Dorsal to adipose distance Post-adipose distance Length of caudal peduncle 17.0 16.8 16.6 14.7–21.4 15.1–19.8 16.2–21.1 18.6±1.87 17.6±1.12 18.6±1.40  Depth of caudal peduncle Body depth at anus Body depth at dorsal-fin origin 9.0 17.2 20.5 8.4–10.9 15.4–20.2 17.4–21.4 9.3±0.66 17.4±1.27 19.6±1.43  Head length Head width Head depth 27.3 20.5 15.7 25.7–30.1 17.7–22.8 14.9–17.5 27.5±1.24 20.2±1.30 16.0±0.80  %HL Snout length Interorbital distance 49 27 46–52 26–32 49±2.1 28±1.7  Eye diameter Nasal barbel length Maxillary barbel length 11 19 93 8–13 17–28 73–107 11±1.2 21±2.5 88±8.9  Inner mandibular barbel length Outer mandibular barbel length 32 49 28–41 43–63 34±3.3 52±6.0 Thoracic adhesive apparatus consisting of narrow keratinized striae in an elongate ovate field extending from isthmus to just beyond posterior limit of pectoral-fin base ( Fig. 3j). Anteromedial striae present. Narrow, v-shaped medial pit on posterior half. Dorsal fin located above anterior third of body, with I,6 (24) rays; fin margin concave; spine short and straight, smooth on anterior and posterior margins. Adipose fin with anterior margin straight or slightly concave and posterior margin straight. Caudal fin strongly forked, with lower lobe slightly longer than upper lobe and i,7,8,i (24) principal rays. Procurrent rays symmetrical and extending only slightly anterior to fin base. Anal-fin base vertically opposite adipose-fin base. Anal fin with straight anterior margin and straight or slightly concave posterior margin; with iv,7,i (4), iv,8 (4), iv,8,i (10), iv,9* (4), iv,9,i (1) or iv,10 (1) rays. Pelvic-fin origin at vertical through posterior limit of dorsal-fin base. Pelvic fin with slightly convex margin and i,5 (24) rays; tip of adpressed fin not reaching anal-fin origin. Pectoral fin with I,7,i (13), I,8 (9), or I,8,i* (2) rays; posterior fin margin slightly concave; anterior spine margin smooth, posterior margin with 5–14 ( holotype=13) serrations.   FIGURE 25.  Glyptothorax pictus, MZB 17218, holotype, 54.2 mm SL; Borneo: Sungai Teweh. Dorsal, lateral and ventral views.  Coloration.In 70% ethanol: dorsal and lateral surfaces of head and body brown or brownish gray, fading to beige or light gray on ventral surfaces. Dorsal and lateral surfaces of head and predorsal region frequently with numerous small darker spots scattered throughout. Mid-dorsal region between base of last dorsal-fin ray and origin of adipose fin with very diffuse pale band. Caudal peduncle slightly paler. Two dark brown to brownish gray vertical bands present on body: one between adipose- and anal-fin bases and other at base of caudal fin. All fins with fin rays proximally brown or brownish gray, becoming hyaline more distally, and diffuse melanophores on fin membranes. Pectoral and pelvic fins with brown or brownish gray on base of fin rays and hyaline posterior twothirds. Pelvic fin with additional diffuse brown band on middle third of pelvic fin present in some individuals. Anal fin with brown or brownish gray base, with diffuse brown or brownish gray spot on anterior third of fin in some individuals. Adipose fin brown or brownish gray with hyaline distal margin. Each caudal-fin lobe with numerous small brown spots finely scattered throughout fin in some individuals; in other individuals, an irregular, elongate brown blotch present on about half of outer fin rays on each lobe; most of inner rays of lobes hyaline. Maxillary and nasal barbels brown or brownish gray dorsally, light gray or beige ventrally. Mandibular barbels light gray or beige.   Distribution.  Glyptothorax pictusis known from the river drainages in southern Borneo, from the Katingan River drainage eastwards to the Barito River drainage ( Fig. 26).  Comparisons.Besides  G. decussatusand  G. exodon(which has already been compard to  G. pictusin the diagnosis), there are three other congeners known from Borneo: G. m a j o r,  G. nieuwenhuisiand  G. stibaros. Besides its color pattern, G. p i c t u sis further distinguished from G. m a j o rin lacking (vs. having) anteromedial striae in the thoracic adhesive apparatus, from both  G. nieuwenhuisiand  G. stibarosin having a deeper caudal peduncle (8.4–10.9% SL vs. 6.9–8.4), and from  G. stibarosin having a smooth (vs. denticulate) posterior margin of the dorsal-fin spine. Among the remaining Sundaic congeners, G. p i c t u sfurther differs from  G. amnestusin lacking (vs. having) anteromedial striae in the thoracic adhesive apparatus, from  G. famelicusin having a deeper body (depth at anus 15.4–20.2% SL vs. 11.4–14.3), a deeper caudal peduncle (8.4–10.9% SL vs. 5.8–7.3) and lacking (vs. having) a prominent pale midlateral stripe on the body, from G. f u s c u sand  G. prashadiin having a concave (vs. straight) margin of the dorsal fin and from  G. kelukin having a straight (vs. convex) dorsoposterior margin of the adipose fin. It is further distinguished from  G. ketambein having a longer pectoral-fin spine (17.3–22.9% SL vs. 14.3– 16.6), a deeper body (depth at anus 15.4–20.2% SL vs. 12.7–15.3), a shorter dorsal-to-adipose distance (14.7–21.4% SL vs. 21.5–25.6) and lacking (vs. having) a prominent pale midlateral stripe on the body, from  G. platypogonin having a longer pectoral-fin spine (17.3–22.9% SL vs. 13.6–17.9) and a straight (vs. convex) dorsoposterior margin of the adipose fin and from  G. plectilisin lacking (vs. having) anteromedial striae in the thoracic adhesive apparatus.  Glyptothorax pictusfurther differs from  G. robustusin having (vs. lacking) a medial pit in the thoracic adhesive apparatus, a deeper caudal peduncle (8.4–10.9% SL vs. 6.6–8.3) and lacking (vs. having) prominent dark longitudinal stripes running through each lobe of the caudal fin, and from  G. schmidtiin having a longer dorsal-fin spine (15.4–20.9% SL vs. 8.9–14.9), a deeper body (depth at anus 15.4–20.2% SL vs. 11.4–15.7), a deeper caudal peduncle (8.4–10.9% SL vs. 5.8–8.7) and lacking (vs. having) a prominent pale midlateral stripe on the body.   Remarks.Specimens of  G. pictusfrom the Katingan River drainage appear to have a more robust body and a steeper predorsal profile ( Fig. 27). However, as we were unable to identify any other differences between material from the Katingan and Barito river drainages, we consider the two populations conspecific. We are also aware of a  Glyptothoraxspecies with a color pattern very similar to  G. pictusknown from the Sesayap River drainage in northeastern Borneo ( Fig. 28). However, the thoracic adhesive apparatus in the Sesayap population possesses anteromedial striae not seen in  G. pictus. Until material is available for study, we identify this species as  G.aff. pictus . 1324948310 1995-10-02 MZB Desa Lampeong II & A. Tjakrawidjaja & A. Mun'im Barito River 49 50 MZB 17218, 54.2 2 Kalimantan Tengah holotype 1324948361 2007-08-11 2007-08-12 2007-08-11 ZRC H. H. Tan -0.06777778 Katingan River 21 112.2825 Bukit Raya-Bukit Baka National Park 49 50 1 Kalimantan Tengah paratype 1324948354 1992-07-15 1992-07-18 1992-07-15 MZB Kecamatan Laung Tuhup & Sungai Laung & Desa Maruwei & A. Tjakrawidjaja & D. Siebert & O. Crimmen Barito River 49 50 MZB 6995 1 Kalimantan Tengah paratype 1324948365 2007-08-12 2007-08-13 2007-08-12 ZRC H. H. Tan Sungai Baha'e -0.79322225 Katingan River 1 112.320335 Bukit Raya-Bukit Baka National Park 49 50 1 Kalimantan Tengah paratype 1324948369 2007-08-12 2007-08-13 2007-08-12 ZRC H. H. Tan -0.74861115 Katingan River 21 112.26417 Bukit Raya-Bukit Baka National Park 49 50 1 Kalimantan Tengah paratype 1324948360 1995-10-02 BMNH Sungai Kias & Desa Tambaba & A. Tjakradwidjaja & A. Mun'im Barito River 49 50 1 Kalimantan Tengah paratype 1324948364 1995-10-02 BMNH Sungai Kias & Desa Tambaba & A. Tjakradwidjaja & A. Mun'im Barito River 49 50 1 Kalimantan Tengah paratype 1324948355 1972-10-22 MZB Batang Alai & Datar Alai & M. A. Rifai Barito River 49 50 MZB 1302 1 Kalimantan Selatan paratype 1324948373 1972-10-25 MZB M. A. Rifai Barito River 49 50 MZB 1306 1 Kalimantan Selatan paratype