Glyptothorax platypogon Valenciennes, in Cuvier & Valenciennes, 1840

Ng, Heok Hee & Kottelat, Maurice, 2016, The Glyptothorax of Sundaland: a revisionary study (Teleostei: Sisoridae), Zootaxa 4188 (1), pp. 1-92 : 55-61

Glyptothorax platypogon Valenciennes, in Cuvier & Valenciennes, 1840

( Fig. 29 )

Pimelodus platypogon Valenciennes, in Cuvier & Valenciennes, 1840: 152 (type locality: Java); Bleeker, 1846a: 136; 1846b: 2; 1855b: 393–394, 396; 1857: 476, 477.

Pimelodus cyanochloros Bleeker, 1846c: 11 (type locality: Java); 1847: 168; 1850: 10; 1857: 477.

Glyptosternon platypogon — Bleeker, 1858c: 217; 1858d: 418; 1858e: 48.

Glyptosternum platypogon —Weber & de Beaufort, 1913: 267 (in part).

Glyptothorax platypogon — Roberts, 1993: 31, Fig. 34 ; Rachmatika, 2003: 59, Pl. 29; Rachmatika et al., 2004: 36; Ng & Hadiaty, 2008: 146, Fig. 6 A; Hadiaty, 2011: 497, Photo 2; Jiang et al., 2011: 280; Bhagawati et al., 2013: 118, Fig. 2 .

Material examined. JAVA : MNHN B.196 (lectotype), 62.7 mm SL; MNHN B.196 (1 paralectotype), 52.6 mm SL; MNHN 2903 (2 paralectotypes), 68.7–71.9 mm SL; RMNH 2998 (3 paralectotypes), 62.6–66.9 mm SL. MZB 1426 (1), 68.5 mm SL; MZB 5692 (1), 32.2 mm SL; Jawa Barat: Sungai Ciliwung at Gadog . MZB 8582 (1), 75.8 mm SL; MZB 8575 (2), 64.0– 70.2 mm SL; MZB 8578 (1), 72.4 mm SL; MZB 8580 (1), 56.0 mm SL; Jawa Barat: Sungai Cisukabirus, a tributary of Sungai Ciliwung at Gadog . ZMA 119.432 (3), 28.9–61.8 mm SL; Banten: Cibodas . MZB 8517 (5), 47.1–58.9 mm SL; Jawa Barat: Desa Leuwi Malang, Sungai Ciliwung . MZB 8513 (18), 31.3–67.5 mm SL; MZB 8516 (35), 24.5–65.0 mm SL; MZB 8595 (16), 23.6–53.2 mm SL; CMK 8980 (5), 44.1– 56.8 mm SL; Jawa Barat: Desa Tugu Utara, Sungai Ciliwung . MZB 1425 (1), 62.9 mm SL; Jawa Barat: Sungai Cisadane at Layungsari . USNM 72545 (2), 60.3–65.7 mm SL; USNM 72546 (1), 72.4 mm SL; ZMA 119.431 (4), 43.0– 57.8 mm SL; Jawa Barat: Bogor . MZB 1512 (6), 27.8–62.5 mm SL; ZRC 11701–11703 (3), 26.3–50.0 mm SL; Jawa Barat: Sungai Cisadane at Bogor . MZB 1312 (12), 33.6–47.6 mm SL; MZB 5557 (1), 30.1 mm SL; Jawa Barat: Sungai Cipakancilan . UMMZ 155697 (3), 49.4–63.9 mm SL; Jawa Barat: Pakancilan near Bogor . MZB 10286 (4), 38.7–74.7 mm SL; MZB 10287 (5), 33.7–48.8 mm SL; Jawa Barat: Sungai Cikaniki at Cilanggar . MZB 10288 (5), 38.1–74.7 mm SL; MZB 10289 (3), 35.8–67.8 mm SL; Sungai Cikaniki at Citalahab . MZB 6250 (11), 32.1–81.1 mm SL; Jawa Barat: confluence of Sungai Cikaniki and Sungai Citalahab . MZB 1427 (1), Jawa Barat: Sungai Cisadane at Maseng, Bogor . ZMA 119.435 (3), 55,5– 71.2 mm SL; Jawa Barat: Gunung Pangrango . ZRC 44074 (3), 52.1–65.0 mm SL; Jawa Barat: Kecamatan Kadudampit, Sungai Cibogo . ZMA 119.979 (1), 66.5 mm SL; Jawa Barat: Sukabumi . ZRC 43876 (24), 34.4–56.3 mm SL; CMK 8983 (3), 45.6–62.3 mm SL; Jawa Barat: Sungai Cisadane near Leuwiliang . MZB 1484 (30), 28.8–65.0 mm SL; Jawa Barat: Sungai Citarum at Kampung Lembur Awi . UMMZ 155796 (2), 33.9–35.0 mm SL; Jawa Barat: Sungai Ciwalen, tributary of Sungai Citanduy at Godebag between Panumbangan and Panjalu . MZB 1481 (1), 91.2 mm SL; Jawa Barat: Sungai Cicangkuan at Cibeureum . ZMA 119.429 (2), 47.8–60.0 mm SL; ZMA 119.433 (1), 58.1 mm SL; Jawa Barat: Garut . ZMA 119.437 (1), 72.9 mm SL; Jawa Barat: Kabupaten Garut, Kecamatan Banjarwangi, Sungai Cikaengan . ZRC 44079 (3), 62.8–66.8 mm SL; Jawa Barat: Ujung Genteng . UMMZ 155696 (1), 60.4 mm SL; UMMZ 155698 (3), 45.7– 65.5 mm SL; Jawa Barat: Sungai Cisokan . ZMA 109.305 (1), 53.0 mm SL; Daerah Istimewa Yogyakarta: Gunung Sewu, River in Gua Gremeng . ZMA 119.438 (1), 79.0 mm SL; Jawa Tengah: Kabupaten Wonosobo, Desa Sapuran . MZB 1310 (6), 46.3–63.1 mm SL; Jawa Timur: Kali Konto at Kedungrejo. CMK 9234 (5), 42.3–52.0 mm SL; Jawa Timur: Kali Brantas basin: Tulungrajo , north of Semen . CMK 9181 (3), 21.3–34.8 mm SL; Jawa Timur: Kali Brantas basin: Kali Kukuan downstream of Seloliman, Kecamatan Trawas . ZMA 119.430 (1), 28.7 mm SL; Jawa Timur: Kali Mandiku near Desa Sumberjambe.

Diagnosis. Glyptothorax platypogon is distinguished from all Sundaic congeners in having the following unique combination of characters: premaxillary toothband approximately half exposed when the mouth is closed; eye diameter 7–9% HL; interorbital distance 28–33% HL; head width 19.4–22.3% SL; in the thoracic adhesive apparatus without anteromedial striae but with medial pit; pectoral-fin spine length 13.6–17.9% SL; smooth posterior margin of dorsal-fin spine; margin of dorsal fin concave; prepelvic length 49.1–54.6% SL; preanal length 65.7–72.3% SL; body depth at anus 15.4–19.0% SL; adipose-fin base length 13.6–18.0% SL; caudal peduncle depth 8.0–11.4% SL (1.4–2.1 times in its length; 1.3–2.0 times in body depth at dorsal-fin origin); caudal peduncle length 15.5–18.2% SL; post-adipose distance 14.6–17.6% SL; and caudal-fin with length 20.1–27.0% SL and broad lobes lacking prominent dark longitudinal stripes running through each lobe.

Description. Morphometric data in Table 11 . 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 16+17=33 (2), 17+16=33 (4), 18+15=33 (1), 16+18=34 (2), 17+17=34 (4), 18+16=34 (7), 17+18=35 (3), 18+17=35 (5), 19+16=35 (2) or 19+17=36 (2).

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 1+6 (4), 1+7 (1) or 2+6 (15) 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.

Thoracic adhesive apparatus consisting of keratinized striae in an ovate field extending from isthmus to before posterior limit of pectoral-fin base ( Fig. 3 k). Anteromedial striae absent. Chevron-shaped medial pit on posterior third.

Dorsal fin located above anterior third of body, with I,6 (20) rays; fin margin convex; spine short and straight, smooth on anterior margin; posterior margin smooth in some individuals and with up to 4 low projections in others. 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 (20) 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 (3), iv,7,i (2), iv,8 (5), iv,8,i (3), iv,9 (5), v,8 (1) or iv,9,i (1) rays. Pelvic-fin origin at vertical through posterior limit of dorsal-fin base. Pelvic fin with slightly convex margin and i,5 (20) rays; tip of adpressed fin not reaching anal-fin origin. Pectoral fin with I,7,i (5), I,8 (13) or I,8,i (2) rays; posterior fin margin slightly concave; anterior spine margin smooth, posterior margin with 6–10 serrations.

Coloration. In 70% ethanol: dorsal and lateral surfaces of head and body medium brown to gray, fading to beige on ventral surfaces. A thin, light brown mid-dorsal stripe extending from base of last dorsal-fin ray to origin of adipose fin; stripe absent in some individuals. Laterosensory pores rimmed in beige, imparting appearance of a diffuse light brown or light gray midlateral line in some individuals. Dorsal and ventral surfaces of caudal peduncle slightly paler in some individuals. All fins with fin rays proximally gray to grayish brown, becoming hyaline more distally, and diffuse melanophores on fin membranes. Pectoral and pelvic fins with gray or brown on base of fin rays and hyaline for at least posterior two-thirds. Anal fin with gray or brown base; gray or brown diffuse spot on anterior third of fin present in some individuals. Adipose fin gray or brown with hyaline distal margin. Base of caudal fin with dark crescent in most individuals. Each caudal-fin lobe with irregular, elongate gray or brown blotch on about half of outer fin rays; most of inner rays of lobes hyaline. Maxillary and nasal barbels gray or brown dorsally, light brown or light gray ventrally. Mandibular barbels beige or light gray.

Habitat and biology. Glyptothorax platypogon inhabits fast-flowing streams with a substrate of gravel and rocks. In the Cisadane River in western Java, it spawns twice a year (once in April and again in July) and feeds primarily on ephemeropteran larvae ( Rachmatika, 1987).

Distribution. Glyptothorax platypogon is known from river drainages in Java, from the Cisadane River drainage eastwards to the Kali Mandiku drainage ( Fig. 24 ).

Comparisons. Glyptothorax platypogon is distinguished from G. robustus , the only other congener known from Java, in having (vs. lacking) a medial pit in the thoracic adhesive apparatus, a convex (vs. straight) dorsoposterior margin of the adipose fin; a deeper caudal peduncle (8.0–11.4% SL vs. 6.6–8.3) and a shorter caudal fin (20.1–27.0% SL vs. 26.5–30.4) with broader lobes lacking (vs. with) prominent dark longitudinal stripes running through each lobe ( Fig. 30 ). The difference in the caudal peduncle depth between G. platypogon and G. robustus is more marked when compared to the body depth at dorsal-fin origin (caudal peduncle depth 1.3–2.0 times in body depth at dorsal-fin origin vs. 2.2–2.8 respectively).

Among the remaining Sundaic congeners, G. platypogon differs from G. amnestus and G. decussatus in lacking (vs. having) anteromedial striae in the thoracic adhesive apparatus and having a plain (vs. mottled and banded respectively) color pattern, and from G. exodon in having the premaxillary toothband approximately half (vs. almost entirely) exposed when the mouth is closed, a smaller eye (diameter 7–9% HL vs. 10–13), a wider head (19.4–22.3% SL vs. 16.0–18.1), a shorter post-adipose distance (14.6–17.6% SL vs. 21.5–24.0), a shorter caudal fin (20.1–27.0% SL vs. 28.0–31.0) and a body with a plain (vs. mottled) color pattern. It is distinguished from G. famelicus in having a deeper body (depth at anus 15.4–19.0% SL vs. 11.4–14.3), a deeper caudal peduncle (8.0– 11.4% SL vs. 5.8–7.3), a shorter post-adipose distance (14.6–17.6% SL vs. 19.1–22.0) and lacking (vs. having) a prominent pale midlateral stripe on the body, from G. fuscus in having a concave (vs. straight) margin of the dorsal fin, a shorter caudal fin (20.1–27.0% SL vs. 28.7–33.9) and a body with a plain (vs. mottled) color pattern, and from G. keluk in having a shorter pectoral-fin spine (13.6–17.9% SL vs. 19.4–22.9) and a shorter caudal fin (20.1– 27.0% SL vs. 26.9–30.7). Glyptothorax platypogon differs from G. ketambe in having a wider head (19.4–22.3% SL vs. 16.1–17.9), a greater prepelvic length (49.1–54.6% SL vs. 45.4–47.8), a deeper body (depth at anus 15.4– 19.0% SL vs. 12.7–15.3), a shorter post-adipose distance (14.6–17.6% SL vs. 19.5–21.7), a shorter caudal peduncle (15.5–18.2% SL vs. 20.1–22.9) and lacking (vs. having) a prominent pale midlateral stripe on the body, from G. major in lacking (vs. having) anteromedial striae in the thoracic adhesive apparatus, and from G. nieuwenhuisi in having a shorter pectoral-fin spine (13.6–17.9% SL vs. 18.1–23.4), a shorter and deeper caudal peduncle (depth 1.4–2.1 times in its length vs. 2.0–2.6) and a body with a plain (vs. mottled) color pattern. It is distinguished from G. pictus in having a shorter pectoral-fin spine (13.6–17.9% SL vs. 17.3–22.9) and a body with a plain (vs. banded) color pattern, from G. platypogonides in having a smaller eye (diameter 7–9% HL vs. 11–14), a shorter pectoral-fin spine (13.6–17.9% SL vs. 17.8–22.7), a deeper body (depth at anus 15.4–19.0% SL vs. 12.1–14.8), a longer adipose-fin base (13.6–18.0% SL vs. 10.7–13.7), a shorter post-adipose distance (14.6–17.6% SL vs. 17.6–21.5), a shorter and deeper caudal peduncle (length 15.5–18.2% SL vs. 18.0–21.5; depth 8.0–11.4% SL vs. 6.5–7.9) and a body with a plain (vs. mottled) color pattern, and from G. plectilis in lacking (vs. having) anteromedial striae in the thoracic adhesive apparatus, having a shorter caudal fin (20.1–27.0% SL vs. 26.6–33.1) and a body with a plain (vs. mottled) color pattern.

Glyptothorax platypogon is further distinguished from G. prashadi in having a concave (vs. straight) margin of the dorsal fin, a longer preanal length (65.7–72.3% SL vs. 61.9–64.7), a shorter post-adipose distance (14.6–17.6% SL vs. 17.9–20.8), a shorter caudal peduncle (15.5–18.2% SL vs. 20.1–22.2), a shorter caudal fin (20.1–27.0% SL vs. 28.3–35.2) and a body with a plain (vs. mottled) color pattern, from G. schmidti in having a deeper body (depth at anus 15.4–19.0% SL vs. 11.4–15.7), a shorter post-adipose distance (14.6–17.6% SL vs. 18.9–22.0), a shorter caudal peduncle (15.5–18.2% SL vs. 18.7–21.4) and lacking (vs. having) a prominent pale midlateral stripe on the body, and from G. stibaros in having the posterior margin of the dorsal-fin spine smooth or with low projections (vs. distinctly serrated), a shorter pectoral-fin spine (13.6–17.9% SL vs. 18.1–22.2), a deeper caudal peduncle (8.0– 11.4% SL vs. 6.9–8.2), a shorter caudal fin (20.1–27.0% SL vs. 26.4–32.3) and a body with a plain (vs. banded) color pattern.

Remarks. Glyptothorax platypogon was described from an indeterminate number of specimens (although Valenciennes used the plural "our specimens", implying that more than one was used in the description). As we have shown in this study, there are two species of Glyptothorax in Java ( G. platypogon and G. robustus ) that are found sympatrically (and sometimes syntopically). Although the syntypes we have examined appear to be a single species, we cannot exclude the possibility that additional syntypes which are not conspecific may exist. We thus designate the 62.7 mm SL specimen in MNHN B.196 as the lectotype of Pimelodus platypogon .

We have followed Bleeker (1858c) in treating Pimelodus cyanochloros as a subjective junior synonym of G. platypogon . Although Fricke (1991) lists SMNS 10569 as syntypes of P. cyanochloros , we are unable to prove their status beyond reasonable doubt. Fricke (2005) cites the reason that Bleeker sent the specimens to the Staatliches Museum für Naturkunde in Stuttgart in 1859–60 while he was still in Batavia (and before he had thought to hold on to the type specimens for use in preparing his Atlas) in considering them as types. However, some of the specimens described by Bleeker as new species in 1846 (including P. cyanochloros ) were already lost when he was transferred to Samarang in 1848 and had to leave his collection in Batavia ( Bleeker, 1878; Boeseman, 1973). The situation is compounded by Bleeker obtaining more specimens subsequent to the description of P. cyanochloros by 1859–60 (e.g. Bleeker 1858e) and his method of storing everything believed to be conspecific in the same container without any labels for individual specimens (Ng et al., 1999). It is thus impossible to ascertain at this time if the SMNS specimens are the syntypes of P. cyanochloros (see Ng et al., 1999 for a similar case regarding Bagrus flavus ).

Figures

FIGURE 2. Glyptothorax amnestus, MZB 17214, holotype, 88.1 mm SL; Sumatra: Padang Panjang. Dorsal, lateral and ventral views.

FIGURE 3. Thoracic adhesive apparatus of: a. Glyptothorax amnestus, ZRC 54231, paratype, 51.2 mm SL; b. G. decussatus, MZB 17216, holotype, 74.5 mm SL; c. G. exodon, BMNH 1982.3. 29.190, paratype, 63.2 mm SL; d. G. famelicus, USNM 193015, holotype, 73.3 mm SL; e. G. f u s c u s, ZRC 42123, 54.3 mm SL; f. G. keluk, MZB 17217, holotype, 52.5 mm SL; g. G. ketambe, MZB 8694, holotype, 100.0 mm SL; h. G. major, ZRC 38761, 59.1 mm SL; i. G. nieuwenhuisi, MZB 16475, 61.0 mm SL; j. G. pictus, MZB 17218, holotype, 54.2 mm SL; k. G. platypogon, ZRC 48376, 56.3 mm SL; l. G. platypogonides, UF 166626, 52.4 mm SL; m. G. plectilis, ZRC 46420, paratype, 44.3 mm SL; n. G. prashadi, CMK 25369, 50.7 mm SL; o. G. robustus, ZRC 48377, 59.9 mm SL; p. G. schmidti, CMK 4536, 74.6 mm SL; q. G. stibaros, MZB 17215, holotype, 55.3 mm SL. Illustrations not to scale.

FIGURE 6. Dorsal views of head of: a. Glyptothorax amnestus, ZRC 38708, 54.1 mm SL; b. G. keluk, MZB 17217, holotype, 52.5 mm SL. Illustrations not to scale.

FIGURE 24. Map showing collection localities of Glyptothorax nieuwenhuisi, G. platypogon and G. platypogonides.

FIGURE 29. Glyptothorax platypogon, ZRC 48376, 56.3 mm SL; Java: Jawa Barat, Cisadane River. Dorsal, lateral and ventral views.

FIGURE 30. Lateral views of caudal region of: a. Glyptothorax platypogon, ZRC 43876, 51.0 mm SL; b. G. robustus, ZRC 43877, 59.9 mm SL. Illustrations not to scale.

FIGURE 34. Glyptothorax prashadi, CMK 25369, 50.7 mm SL; Myanmar: Kyenchaung River. Dorsal, lateral and ventral views.

Tables

TABLE 11. Morphometric data for Glyptothorax platypogon (n = 20).

	Range	Mean±SD
Standard length (mm)	47.7–66.9
%SL
Predorsal length	34.5–40.0	37.5±1.39
Preanal length	65.7–72.3	69.2±1.93
Prepelvic length	49.1–54.6	52.1±1.76
Prepectoral length	19.4–25.8	22.4±1.88
Length of dorsal-fin base	12.4–14.9	13.7±0.86
Dorsal-fin spine length	13.4–17.1	15.8±0.99
Length of anal-fin base	13.7–17.4	15.6±1.14
Pelvic-fin length	14.0–17.4	15.6±0.92
Pectoral-fin length	20.7–25.5	23.3±1.19
Pectoral-fin spine length	13.6–17.9	16.2±1.30
Caudal-fin length	20.1–27.0	25.0±2.13
Length of adipose-fin base	13.6–18.0	15.8±1.34
Dorsal to adipose distance	18.9–24.5	21.3±1.39
Post-adipose distance	14.6–17.6	15.7±1.14
Length of caudal peduncle	15.5–18.2	16.5±0.68
Depth of caudal peduncle	8.0–11.4	9.6±0.86
Body depth at anus	15.4–19.0	16.5±0.90
Body depth at dorsal-fin origin	19.4–23.1	21.0±1.15
Head length	25.6–29.6	27.5±1.07
Head width	19.4–22.3	20.7±0.84
Head depth	13.4–18.4	15.8±1.33
%HL
Snout length	44–51	48±1.9
Interorbital distance	28–33	31±1.5
Eye diameter	7–9	8±0.8
Nasal barbel length	19–30	24±3.4
Maxillary barbel length	70–99	86±10.2
Inner mandibular barbel length	22–35	28±4.5
Outer mandibular barbel length	35–52	43±6.0