Nemacheilus marang Hadiaty & Kottelat, 2010, new species
Creators: name: Hadiaty, Renny Kurnia
name: Kottelat, Maurice
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Cypriniformes
Nemacheilidae
Nemacheilus
Nemacheilus marang

description: Nemacheilus marang, new species
(Figs. 2–3)
Holotype. MZB 13301, 38.9 mm SL (49.4 mm TL); Indonesia: Kalimantan Timur: Kabupaten Kutai Timur: Kecamatan Kelai: Tepian Langsat village, Sungai Marang (1°42.47'N 117°45.55'E), Bengalon drainage; R. K. Hadiaty, Sugeng & July, 25 August 2004.
Paratypes. ANSP 187007, 1, 43.0 mm SL (53.6 mm TL); BMNH 2006.3.20.2, 2, 38.5–40.7 mm SL (48.8–50.8 mm TL); UF 165708, 2, 39.6–43.8 mm SL (50.6–55.0 mm TL); USNM 388745, 2, 38.7–40.9 mm SL (48.9–51.8 mm TL); ZRC 50729, 2, 34.9–36.4 mm SL (44.8–45.8 mm TL); CMK 20314, 2, 40.1–44.2 mm SL (50.9–56.2 mm TL); CMK 18908, 2, 41.9–49.6 mm SL (54.3–62.6 mm TL); same data as holotype. — MZB 13321, 4, 37–51.6 mm SL (46.8–65.7 mm TL); Indonesia: Kalimantan Timur: Kabupaten Kutai Timur: Kecamatan Kelai: Tepian Langsat village, Sungai Jelai (1°40.60'N 117°16.75'E); R. K. Hadiaty, Sugeng & July, 26 August 2004.
Additional material (non types). MZB 13295, 1, 41.5 mm SL (54.1 mm TL); Indonesia: Kalimantan Timur: Kabupaten Kutai Timur: Kecamatan Kelai: Tepian Langsat village, Sungai Marang (1°42.47'N 117°45.55'E); Daeng, 21 August 2004. — MZB 13302, 1, 39.6 mm SL (50.5 mm TL); Indonesia: Kalimantan Timur: Kabupaten Kutai Timur: Kecamatan Kelai: Tepian Langsat village, Sungai Marang (1°42.47'N 117°45.55'E); Daeng, 23 August 2004. — MZB 13304, 3, 41.7–45.8 mm SL (53.2–58.8 mm TL); Indonesia: Kalimantan Timur: Kabupaten Kutai Timur: Kecamatan Kelai: Tepian Langsat village, mouth of Sungai Marang (1°40.60'N 117°16.75'E); R. K. Hadiaty, Oman & Sugeng, 24 August 2004. — MZB 13306, 10, 37.5–54.7 mm SL (48.1–69.2 mm TL); Indonesia: Kalimantan Timur: Kabupaten Kutai Timur: Kecamatan Kelai: Tepian Langsat village, mouth of Sungai Marang (1°40.60'N 117°16.75'E); R. K. Hadiaty, Oman & Sugeng, 25 August 2004.
Diagnosis. Nemacheilus marang is distinguished from the other species of Nemacheilus known from Borneo by its unique colour pattern, which is made of 10–18 dark brown bars on the flank, extending from the dorsal midline to just below the lateral line, continuous across the back, not or only slightly wider on the back and where crossing the midlateral stripe; the bars usually similarly-shaped, straight, and of width less than half that of interspaces. In the other Bornean species (except N. olivaceus) the bars are even less regular (N. saravacensis, N. longipectoralis), or dissociated into a midlateral series of blotches and a mid-dorsal series of saddles (N. kapuasensis, N. elegantissimus); see Remarks for more information on the colour pattern of the other species.
Other diagnostic characters (none unique to N. marang) are: scales of the row above and below the lateral line on caudal peduncle not elongate and without a tubercle at their posterior extremity (vs. scales elongate and with a tubercle in N. spiniferus, N. selangoricus and N. tebo); pectoral fin reaching only slightly beyond half of distance to pelvic-fin base (vs. to pelvic-fin origin or beyond in N. longipectoralis); caudal fin forked, its upper lobe 1.0–1.5 times longer than its median rays (vs. deeply emarginate, the upper lobe 1.1–1.3 times longer than the median rays in N. olivaceus); anus located behind middle of distance between pelvic-fin base and anal-fin origin (vs. about at midlength in N. olivaceus); anterior nostril at the front side of a pointed flap (vs. at the extremity of an obliquely cut tube in N. saravacensis, N. longipectoralis, N. selangoricus and N. spiniferus); 17 branched caudal-fin rays (vs. 16 in most specimens of N. saravacensis); 8½ branched dorsalfin rays (vs. 9–10½ in N. saravacensis, 9½ in N. longipectoralis, N. kapuasensis, N. selangoricus and N. spiniferus); and 84–92 lateral-line pores (vs. 93–102 in N. kapuasensis).
Description. See Figures 2–3 for general appearance and Table 1 for morphometric data of holotype, 17 paratypes and 12 non-type specimens. Body elongate, depth slowly increasing up to dorsal-fin origin. Behind dorsal fin, body depth decreasing slowly to caudal-fin base. Head slightly depressed; body slightly compressed anteriorly to compressed posteriorly.
standard deviation (s.d.) include data of holotype.
holotype range mean s.d.
Standard length 38.9 34.9–54.1
Total length 49.4 44.8–69.6
In percent of standard length
Total length 127.0 123.6–130.5 126.3 1.6 Lateral length of head 23.9 22.0–26.5 23.9 1.1 Dorsal length of head 18.8 18.8–22.1 20.2 0.9 Predorsal length 48.9 46.7–52.5 48.9 1.3 Prepelvic length 51.0 49.3–54.3 51.0 1.5 Preanal length 76.6 75.1–79.8 77.0 1.3 Preanus length 67.6 63.3–72.4 68.5 2.4 Head depth at eye 9.5 8.3–12.2 10.2 1.0 Head depth at nape 12.6 11.7–14.2 12.9 0.7 Body depth at dorsal-fin origin 14.9 14.0–20.7 16.9 1.7 Depth of caudal peduncle 11.3 10.7–13.0 11.5 0.5 Length of caudal peduncle 15.2 13.5–16.0 15.0 0.7 Snout length 9.0 8.0–10.8 9.1 0.9 Head width at nares 8.2 7.3–9.1 7.3 0.5 Maximal headwidth 12.6 12.0–15.0 13.4 0.8 Body depth at dorsal-fin origin 9.8 9.7–15.7 11.8 1.7
continued next page Dorsal fin with 4 simple and 8½ branched rays. Anal fin with 3 simple and 5½ branched rays. Pectoral fin with 11–13 rays, reaching ½ to 2/3 of distance to pelvic-fin base. Pelvic fin with 8 rays, origin below base of branched dorsal-fin ray 1 or 2, reaching about midway of distance to anal-fin origin; just reaching anus, which is about 1.5–2 eye diameter in front of anal fin. Axillary pelvic lobe present. Caudal fin with 8+9 branched rays, forked, lobes subequal, upper lobe 1.0–1.5 times longer than median rays. Caudal peduncle 1.1–1.5 times longer than deep, with low dorsal and ventral adipose crests on posterior half. Distal margin of dorsal fin straight. Largest recorded size 54.7 mm SL (MZB 13306).
Body entirely covered by deeply embedded scales. No scales on belly in front of pelvic-fin base (one specimen with scales extending forward until almost between pectoral-fin base). Lateral line complete, straight, with 84–92 pores. Cephalic lateral line system with 5 supraorbital, 4+11–12 infraorbital, 9–10 preoperculo-mandibular and 3 supratemporal pores.
Anterior nostril pierced in front side of a pointed flap. Mouth gape about 2 times wider than long (Fig. 4 b). Lips thin but fleshy, lower lip in some specimens with a few shallow grooves in median area. No median incision in upper lip. No median interruption in lower lip. Processus dentiformis present. No median notch in lower jaw. Inner rostral barbel reaching below anterior half of eye; outer one reaching about vertical of middle of eye. Maxillary barbel reaching posterior margin of eye.
Sexual dimorphism. Males with suborbital flap (Fig. 4 a).
Coloration. Body background colour pale yellowish brown, somewhat darker on back, paler on belly. A deep layer of pigment making a dark greyish axial stripe along lateral line. 10–18 dark brown bars on flank, extending from dorsal midline to just below mid-lateral stripe, continuous across back, not or only slightly wider on back and where crossing midlateral stripe. Bars usually all similarly shaped (Fig. 3 shows one of the less regularly patterned specimen), straight, their width less than half that of interspaces. Bars on caudal peduncle (and sometimes on posterior half of body) usually dissociated into a small saddle on dorsal midline and a blotch on midlateral stripe. A conspicuous black blotch on upper part of lower half of caudal-fin base, slightly vertically elongated, not reaching ventral midline; a fainter spot at upper part of caudal-fin base, close to dorsal midline; space between these two marks pale yellow; another small pale yellow patch in front of lower spot. Top of head dark grey, a darker triangular blotch on nape, a darker band between eyes, a pair of longitudinal darker lines between nostrils and tip of snout.
Dorsal fin hyaline, with two or three rows of faint brown spots on rays. Caudal fin hyaline with two or three irregular vertical rows of faint brown spots on median rays, other rays unmarked. Other fins hyaline.
In life: background pale greyish yellow, markings as above, dark grey.
Notes on habitat and biology. At the type locality, Sungai Marang was about 10 m wide (dry season conditions) and about 50 cm deep with the bottom made of a smooth rock layer, without any relief, with fast current and clear water. Nemacheilus marang was collected in submerged debris and leaf litter along the edge but was totally absent in the middle of the stream.
In Sungai Jelai, the bottom is made of large stones and mud. Nemacheilus marang was less abundant than at the type locality. It was obtained from submerged debris and leaf litter that accumulates around the large stones. The samples from the Marang area include only 15 other fish species.
One female (MZB 13306, 52.1 mm SL) was dissected and its ovaries contained 3942 ripe eggs, 0.4–0.6 mm diameter. The size of all eggs is almost similar, indicating that N. marang is a total spawner.
Distribution. Nemacheilus marang is presently known only from the Marang and Jelai Rivers in Jelai drainage, East Kalimantan (Fig. 1). The Jelai is a tributary of Sungai Bengalon, which flows into the Straits of Sulawesi.
Etymology. Named after the type locality Sungai Marang. A noun in apposition.
Remarks. Seven species of the genus Nemacheilus are known from Borneo (Kottelat, 1984; Chin & Samat, 1992; Hadiaty & Kottelat, 2009): N. elegantissimus, N. kapuasensis, N. longipectoralis, N. olivaceus, N. saravacensis, N. spiniferus and N. tebo. Three additional species have been at some time placed in Nemacheilus but are now in the genera Sundoreonectes (N. obesus, Elxis sabanus) and Schistura (N. maculiceps) (Kottelat, 1990; Chin, 1990; Kottelat et al., 1993). Among the Bornean Nemacheilus, Hadiaty & Kottelat (2009) recognised a N. selangoricus group diagnosed by the presence of two rows of modified, elongated scales on the caudal peduncle, with a tubercle on their posterior extremity, often at the tip of an acuminate process. In Borneo, this group includes N. spiniferus and N. tebo. In addition, there is a single record of N. selangoricus from Sabah based on specimens collected in 1956 (Kottelat, 1990). The species has not been collected again in Sabah and its presence needs confirmation; there are indications that specimens from different lots and their respective labels may have been mixed by an earlier researcher. Nemacheilus selangoricus is known from Sumatra and the southern Malay Peninsula. The remaining species have not been classified into groups.
The colour pattern of N. marang distinguishes it from the other species of Nemacheilus of Borneo and only shares gross similarity with that of N. olivaceus.
Nemacheilus olivaceus (from Sabah; Fig. 5) has a colour pattern made of 12–15 dark-brown bars, regularly shaped except for the last few ones, slightly narrower or equal to interspaces; without conspicuous axial stripe; no patterning on the dorsal fin, except in very few specimens, which have a faint subdistal row of brown spots on rays; and the blackish brown bar at caudal-fin base made of a lower elongate, straight vertical part on lower 2/3 of caudal, and an upper slanted blackish mark, more or less reaching lower one. Further N. marang is distinguished from N. olivaceus by the absence of a median notch in lower lip (vs. presence), a forked caudal fin (vs. deeply emarginate), and the anus located more posteriorly (behind middle of distance between pelvic-fin base and anal-fin origin, vs. about in the middle).
Nemacheilus kapuasensis (from Kapuas drainage, Kalimantan Barat; Fig. 6) has a colour pattern made of 10–12 broad dark-brown bars (width equal to interspaces), in large specimens broken up into a series of saddles alternating with a series of midlateral blotches. Nemacheilus marang is further distinguished from N. kapuasensis in having 8½ branched dorsal-fin rays (vs. 9½) and fewer lateral-line pores (84–92, vs. 93–102).
Nemacheilus elegantissimus (from Sabah; Fig. 7) has a midlateral row of 17–21 small, vertically elongated black blotches, about 17–21 saddles along the dorsal mid-line, a vertically elongated black spot occupying most of the lower half of the caudal-fin base, circled by a whitish area. Further, in N. marang the dorsal fin pattern is restricted to 2–3 rows of faint brown spots on rays, while in N. elegantissimus part of the anterior edge of the fin is black, there are 2 rows of black spots on rays, one subdistal and one subproximal; and 2–3 black blotches extending on membranes over the subproximal row. Nemacheilus marang also has a somewhat stouter body (body depth 14.0–20.7 % SL, vs. 10.7–18.9 [examined material and from Chin & Samat, 1992]).
Nemacheilus longipectoralis (from Sabah and Kalimantan Timur; Fig. 8) has a colour pattern made of 16– 20 long, narrow dark brown bars, irregularly shaped, some connected, some branched, continuous or not across the back, often appearing as pairs of bars connected to a single saddle in front of dorsal fin. In N. marang the dorsal-fin pattern is restricted to 2–3 rows of faint brown spots on rays, while in N. longipectoralis part of the anterior edge of the fin is black; there are 2 rows of black spots on rays, one subdistal and one at about 1/3 the length of the rays; the anterior spot of the lower row is enlarged and extends over the first two branched rays and the membrane inbetween. Further, in N. marang, the pectoral fin reaches only slightly beyond half of distance to pelvic-fin base (vs. almost to pelvic-fin origin in material from Sabah and beyond in material from the Mahakam drainage [type series]).
Nemacheilus saravacensis (from Kalimantan Barat and Sarawak; Fig. 9) has a colour pattern made of 13– 17 irregular brown blotches along the lateral line, most extending to dorsal midline and those on caudal peduncle extending to ventral midline; 13–17 dark brown saddles along back, connected or not to midlateral blotches. Nemacheilus marang is further distinguished from N. saravacensis in having 17 branched caudal-fin rays (vs. 16 in most specimens), 8½ branched dorsal-fin rays (vs. 9–10½), and the anterior nostril at the front side of a pointed flap (vs. at extremity of an obliquely cut tube with pointed tip).
Nemacheilus selangoricus (doubtfully present in Sabah, see above; Fig. 10) has a colour pattern made of conspicuous dark brown bars, much wider than interspaces, a conspicuous blackish bar across eye, and a large black spot at the base of the anterior rays of the dorsal fin. Nemacheilus marang is further distinguished from N. selangoricus in having a less deeply forked caudal fin (upper lobe 1.0-1.5 times median rays, vs. 1.5–2.4) with subequal lobes (vs. upper lobe 1.1–1.3 times longer than lower one), anterior nostril pierced in front side of a pointed flap (vs. at tip of a small tube), and without acuminate scales (vs. conspicuous acuminate scales on caudal peduncle).
Comparative material. Morphometric data are in part from Kottelat (1984) and from our examination of the following material:
Nemacheilus elegantissimus: ZRC 40381, 1, 47.8 mm SL; Sabah: Lahad Datu district: Danum Valley, Sungai Lonpodas: K. Martin-Smith, 4 June 1996. — CMK 7937, paratype, 46.0 mm SL; Sabah: Lahad Datu district: Danum Valley, Sungai Payau; A. Samat, 7 December 1990.
Nemacheilus kapuasensis: ZRC 44047, 1, 60 mm SL; Malaysia: Sarawak: Bau area; H. H. Tan, 24 April 2004. — ZRC 38823, 2, 51.4–52.9 mm SL, Indonesia: Borneo: Kalimantan Barat: Kapuas drainage, Sungai Lanjak in Lanjak and Sungai Lanjak Deras 1 km east of Lanjak; M. Kottelat, 11 June 1995. — CMK 3187, 3, 41.2-54.0 mm SL; Borneo: Kalimantan Barat: Kapuas drainage: Sungai Pinoh at Nangu Saian, 45 km S of Nangapinoh; T. R. Roberts, 26 July 1976.
Nemacheilus longipectoralis: RMNH 7641, lectotype, 34.4 mm SL; Indonesia: Borneo: Kalimantan Timur: upper Mahakam; A. W. Nieuwenhuis, November 1898. — RMNH 27350, 2 paralectotypes, 28.9–36.7 mm SL; Indonesia: Borneo: Kalimantan Timur: upper Mahakam; A. W. Nieuwenhuis, November 1898. — MZB 16479, 1, 39.4 mm SL; Indonesia: Borneo: Kalimantan Timur: Mahakam drainage: Sungai Pleo, Sungai Senget Kiri; R. K. Hadiaty et al., 6 June 2008. — ZRC 40383, 3, 33.7–38.3 mm SL; Sabah: Lahad Datu district: Danum Valley, Sungai Lonpodas; H. H. Tan & Y. Y. Goh, 3 October 1996.
Nemacheilus olivaceus: ZRC 43986, 1, 49.8 mm SL; Malaysia: Sabah: Danum Valley, small tributary to Sungai Bole, ca. 500 m into coupe 93, H. H. Tan & Y. Y. Goh, 2 October 1996. — ZRC 45411, 1, 43.9 mm SL; Borneo: Sabah: Danum Valley; H. H. Tan & Y. Y. Goh; 1 October 1996. — ZRC 45485, 5, 40.6–48.5 mm SL; Borneo: Sabah: tributary of Segama; Y. Y. Goh, 23 September 1998.
Nemacheilus saravacensis: BMNH 1893.3.2.277, lectotype, 42.1 mm SL; Borneo: Sarawak: Senah; Everett.
description: Published as part of Hadiaty, Renny Kurnia & Kottelat, Maurice, 2010, Nemacheilus marang, a new loach (Teleostei: Nemacheilidae) from Sangkulirang karst, eastern Borneo, pp. 39-48 in Zootaxa 2557 on pages 41-47, DOI: 10.5281/zenodo.196937