Paracanthocobitis nigrolineata

Page, Lawrence M., 2017, A revision of the Paracanthocobitis zonalternans (Cypriniformes: Nemacheilidae) species complex with descriptions of three new species, Zootaxa 4324 (1), pp. 85-107: 98-101

publication ID

publication LSID

persistent identifier

treatment provided by


scientific name

Paracanthocobitis nigrolineata

new species

Paracanthocobitis nigrolineata  , new species

Blacklined Zipper Loach

Figs. 8View FIGURE 8 & 9View FIGURE 9

Holotype. NIFI 5080View Materials, 33.1View Materials mm SL, Thailand, Kanchanaburi Province, Thong Pha Phum, Mae Khlong drainage, unnamed tributary of Khwae Noi just S of rte. 323, 14.540N, 98.780E, 27 January 2015.GoogleMaps 

Paratypes. Thailand, Kanchanaburi Province: ANSP 179829, 2, 35.6–36 mm SL, Ulong River, tributary of Khwae Noi, at rte. 323 bridge, 5–10 km from Thong Pha Phum , 14.782N, 98.669E, 4 March 2001GoogleMaps  ; NIFI 3087, 4, 27–29.4 mm SL, Thong Pha Phum, Huay Ulong, 14.760N, 98.638E, no date; UF 188053View Materials, 9, 24.9–35.8 mm SL, same locality as holotype, 27 January 2015GoogleMaps  ; UMMZ 209461, 7, 29.9–35.5 mm SL, Khwae Yai , 14.227N, 99.234E, 28 February 1975GoogleMaps  ; Ratchaburi Province: ZRC 42002View Materials, 2, 29.7–42.4 mm SL, Suan Pheng District, Suan Pheng Waterfall , 13.524N, 99.239E, no date.GoogleMaps 

Diagnosis. Paracanthocobitis nigrolineata  is distinguished from all other species of Paracanthocobitis  by combination of incomplete lateral line ending near dorsal-fin insertion; 9½–10½ branched dorsal-fin rays; axillary pelvic lobe present; black stripe along side of body, ending near caudal-fin, usually overlying black lateral blotches extending ventrally from lateral stripe; circular black spot on upper margin of caudal-fin base; black pigment extending from lateral stripe onto pectoral-fin base; no marmorated pattern anterior to dorsal-fin origin; black dorsal saddles short, not connecting to lateral blotches; 8 branched upper caudal-fin rays.

Description. Meristic and morphometric data are in Tables 4 and 5. Body deepest just anterior to dorsal-fin origin; slightly compressed before dorsal fin, strongly compressed postdorsally. Head depressed, snout gently rounded to slightly pointed when viewed dorsally or laterally. Dorsal-fin origin far in front of pelvic-fin origin; distal margin convex. Pectoral fin 0.18–0.23 SL, not reaching pelvic fin; pelvic fin 0.16–0.19 SL, not reaching anal fin; caudal fin emarginate. Lateral line incomplete, reaching just beyond dorsal-fin insertion; 21–56 pores. Axillary pelvic lobe present. Mouth arched with heavily papillated lips; upper lip with 3–5 rows of papillae, continuous with large pads on lower lip. Three pairs of barbels; inner rostral barbel extends to or slightly past base of maxillary barbel, maxillary barbel and outer rostral barbel extend to or slightly past eye. Body covered with scales; 9½ (13 specimens)–10½ (66 specimens) branched dorsal-fin rays; 9–13, usually 10, pectoral-fin rays; 6 pelvic-fin rays; 5½ branched anal-fin rays; 8 branched upper caudal-fin rays; 8 branched lower caudal-fin rays. Suborbital flap in male. Maximum SL 42.4 mm female.

Body yellow-brown with 10–13 dark brown to black blotches along lateral line overlain with black stripe usually obscuring lateral blotches and ending at caudal-fin origin; 13–24 small dark brown dorsal saddles. Dark spots and blotches on head; uninterrupted black bar from eye to tip of snout. Ocellus with black center near upper margin of caudal peduncle; 3–6 concentric rows of dark spots in dorsal fin, 2–3 rows of dark spots in anal fin, 4–6 dark bands on caudal fin. Black lateral stripe extending onto pectoral-fin origin.

Comparisons. Paracanthocobitis nigrolineata  differs from all other species of Paracanthocobitis  except P. zonalternans  , P. phuketensis  , P. triangula  , and P. marmorata  in having an incomplete lateral line ending near the dorsal-fin insertion (vs. lateral line to the end of the caudal peduncle) and 9½–10½ (vs.>10½) branched dorsal-fin rays. Paracanthocobitis nigrolineata  is most similar morphologically to P. zonalternans  but differs in having a black stripe along the side of the body, usually overlying black lateral blotches, ending near the caudal fin (vs. stripe absent or dusky and ending near the dorsal-fin insertion), and in always having 8 (vs. sometimes 7) upper branched caudal-fin rays. Paracanthocobitis nigrolineata  differs from P. phuketensis  in having a black stripe along the side of the body, usually obscuring black lateral blotches (vs. a series of black blotches, sometimes overlain with a faint dusky stripe not obscuring the black blotches); black pigment extending from the lateral stripe onto the pectoral-fin base; axillary pelvic lobe present (vs. absent, occasionally rudimentary), and 8 (vs. sometimes 7) branched upper caudal-fin rays. Paracanthocobitis nigrolineata  differs from P. triangula  in having a circular (vs. triangular  ) black spot on the upper margin of the caudal-fin base and in having black pigment extending from the lateral stripe onto the pectoral-fin base. Paracanthocobitis nigrolineata  differs from P. marmorata  in having a circular (vs. teardrop-shaped) black spot on the upper margin of the caudal-fin base, black pigment extending from the lateral stripe onto the pectoral-fin base, an axillary pelvic lobe, and in not having a marmorated pattern between the dorsal saddles and lateral blotches.

Distribution. Paracanthocobitis nigrolineata  is known from Irrawaddy and Sittang drainages of Myanmar and the Mae Khlong drainage of Thailand with a large geographic gap in-between ( Fig. 5View FIGURE 5). This gap is likely due to the paucity of sampling in Myanmar.

Etymology. The epithet nigrolineata  refers to the black stripe along the side of the body.

Material Examined (excluding types). Myanmar: Irrawaddy drainage: CASAbout CAS 32368View Materials, 13View Materials, 19.0– 26.6 mm, near Indaw, Chaung and Karnaing, 24.226N, 96.143EGoogleMaps  ; CAS 34752View Materials, 2, 23.5–31.3 mm, Ngamoeyeik Creek , 9 mi NW Hlegu, 17.219N, 96.201EGoogleMaps  ; UF 30191, 2, 36.3– 35.7 mm, Gyobu Reservoir , 9 km N of Taik-Kyi Taik-Kyi township, Rangoon, 16.831N, 96.250EGoogleMaps  ; ZRCAbout ZRC 43453View Materials, 10View Materials, 17.3View Materials –38.0 mm, Shan State, Ma Gawe River, along Kalaw-Thazi Hwy between Mandalay and Nampantet, 21.397N, 96.245EGoogleMaps  . Sittang drainage: USNM 378439, 10, 31.5–39.7 mm, Kayin Stream near the Sittang River, east of Taungoo , 18.958N, 96.478EGoogleMaps  . Thailand: Kanchanaburi Province: Mae Khlong drainage: NIFIAbout NIFI 0 1435, 13, 24.6–32.0 mm, Khao Noi , 13.967N, 99.590EGoogleMaps  ; NIFIAbout NIFI 0 2057, 7, 19.9–33.9 mm, same locality as NIFI 01435View Materials; UF 172979View Materials, 1, 31.3 mm, Lichia River , at 323 bridge, 15.071N, 98.581EGoogleMaps  ; UF 176389View Materials, 2, 29.1–34.8 mm, Huay Ka Yeng County, Kring Ta Ko , 14.753N, 98.501EGoogleMaps  ; UF 176411View Materials, 1, 22.8 mm, Huay Ka Yeng , at 3272 bridge, 14.660N, 98.534EGoogleMaps  ; UF 176449, 35 (10 ex.), 22–30.1 mm, Mae Nam Khwae, Huay Ban Rai, 14.7193N, 98.506E; UF 176546View Materials, 2, 24.9–25.5 mm, Huay Ka Yeng, trib. of Mae Nam Khwae at Huay Pok Kok , 14.680N, 98.527EGoogleMaps  ; UF 176554View Materials, 23 (10 ex.), 25.4– 24.4 mm, same locality as UF 176449View MaterialsGoogleMaps  ; UF 181138View Materials, 2, 34.5–36.4 mm, Mae Nam Khwae Noi at Ban Huay Pakkok , 14.380N, 98.480N  ; UF 181149View Materials, 7, 29–36.4 mm, Pakkok River— Mae Nam Khwae Noi at Ban Huay Paousa , 14.633N, 98.800EGoogleMaps  ; UF 182821View Materials, 13, 27.7–37.4 mm, Thong Pha Phum , near rte. 3272, 14.690N, 98.521EGoogleMaps  ; UF 188054View Materials, 3, 33.8–38.8 mm, Thong Pha Phum, Mae Klong River , 14.650N, 98.530EGoogleMaps  ; UF 188055View Materials, 4, 25.7–31.6 mm, Sangkhla Buri Co., Song Karia River at rte. 323, 15.220N, 98.440EGoogleMaps  ; UF 188056View Materials, 1, 25.4 mm, Sangkhla Buri Co., unnamed trib of Lake Vajiralongkorn , 15.060N, 98.560EGoogleMaps  .


California Academy of Sciences


Zoological Reference Collection, National University of Singapore


National Inland Fisheries Institute