Paracanthocobitis phuketensis ( Klausewitz, 1957 )

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 : 94-96

Paracanthocobitis phuketensis ( Klausewitz, 1957)

Phuket Zipper Loach

Figs. 6 & 7

Noemacheilus phuketensis Klausewitz, 1957:195 , fig. 1. Type locality: Phuket Island, Thailand. Holotype: SMF 3966.

Acanthocobitis phuketensis .— Bănărescu & Nalbant, 1964:160.

Noemacheilus (Acanthocobitis) phuketensis .— Bănărescu & Nalbant, 1968:322.

Diagnosis. Paracanthocobitis phuketensis 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 usually absent, occasionally rudimentary; series of black blotches, sometimes overlain with faint dusky stripe along side of body not obscuring lateral blotches, ending near caudal-fin; circular black spot on upper margin of caudal-fin base; black pigment not extending from black blotches along side of body onto pectoral-fin base; no marmorated pattern anterior to dorsal-fin origin; dorsal saddles longer than interspaces, frequently connecting to lateral blotches; 7–8 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 0.18–0.28 SL, not reaching pelvic fin; pelvic fin 0.16–0.22 SL, not reaching anal fin; caudal fin emarginate. Lateral line incomplete, reaching just beyond dorsal-fin insertion; 20–48 pores. Axillary pelvic lobe usually absent, occasionally rudimentary. 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 (5 specimens)–10½ (50 specimens) branched dorsal-fin rays; 9–10, usually 9, pectoral-fin rays; 6 pelvic-fin rays; 5½ branched anal-fin rays; 7–8 branched upper caudal-fin rays; 8 branched lower caudal-fin rays. Suborbital flap in male. Maximum SL 33.3 mm female.

Body yellowish-brown with 10–12 dark brown to black blotches along lateral line sometimes overlain with faint dusky stripe usually ending near caudal fin; 12–15 small dark brown dorsal saddles; dorsal saddles longer than interspaces, frequently connecting to lateral blotches. 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. Dusky lateral stripe not extending onto pectoral-fin origin.

Comparisons. Paracanthocobitis phuketensis differs from all other species of Paracanthocobitis except P. zonalternans , P. nigrolineata , 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 phuketensis differs from P. zonalternans in not having black pigment extending from a black lateral stripe onto the pectoral-fin base; axillary pelvic lobe usually absent, occasionally rudimentary (vs. always present); and in having dorsal saddles longer than interspaces that frequently connect to lateral blotches vs. short (not extending ventrally to dorsal stripe) dorsal saddles that rarely connect to lateral blotches. Paracanthocobitis phuketensis differs from P. nigrolineata in not having a distinct black stripe along the side of the body obscuring the lateral blotches and black pigment extending from the lateral stripe onto the pectoral-fin base; and axillary pelvic lobe usually absent, occasionally rudimentary (vs. always present). Paracanthocobitis phuketensis differs from P. triangula in having a circular (vs. triangular ) black spot on the upper margin of the caudal-fin base, and axillary pelvic lobe usually absent, occasionally rudimentary (vs. always present). Paracanthocobitis phuketensis differs from P. marmorata in having a dusky lateral stripe along the side of the body (vs. no stripe); axillary pelvic lobe usually absent, occasionally rudimentary (vs. always absent); a circular (vs. tear-drop shaped) black spot on the upper margin of the caudal-fin base; and in not having a marmorated pattern between the dorsal saddles and lateral blotches. Paracanthocobitis phuketensis from Phuket Island and Phang-Nga river drainages further differs from P. nigrolineata , P. triangula , and P. marmorata in sometimes having 7 (vs. always 8) upper branched caudal-fin rays.

Distribution. Paracanthocobitis phuketensis is known from Peninsular Thailand in the Panang Tak drainage and on Phuket Island, south to the Perlis, Padang Sarai, and Ketil drainages of Peninsular Malaysia ( Fig. 5 ).

Material Examined. Malaysia: Malay Peninsula: MCZ 47226, 1 , 26.9 mm, Satun Malay Peninsula, Boripatra River , on road from Satun to Hat Tai., 6.815N, 99.974E ; ZRC 41103, 1 , 17.1 mm, Perlis Sintok-Pdg., Senai Road, 6.456N, 100.491E ; ZRC 46671, 3, 22.9–27.8 mm, Kedah Kg. Tandop about 6–7 mi from Baling on road to Weng, 5.665N, 100.901E . Thailand: Phang-Nga drainage: UF 182833, 4, 23.6–27.3 mm, near Phang Nga, off rte. 4090, 8.571N, 98.418E ; Tapi ( Tapee ) drainage: UF 183331, 2, 31.3–33.3 mm, Nakhon Si Thammarat Province, near rte. 4015, 8.349N, 99.692E ; NIFI 0 2181, 2, 27.0– 27.1 mm, Surat Thani Province, Suratthani Tapi (Tapee) drainage, Khlong Sok at Ban Kheng Sok, 8.907N, 98.522E ; Kraburi drainage: UF 236043, 16 (10 ex.), 23.3–31.3 mm, Ranong, Kraburi River at Khlong Bangsikim, trib. of Laoun River , km 3/537 near Ban Kreo Noi , 10.1505N, 98.717E ; ZRC 42198, 3, 24.7–30.9 mm, Ranong Province, Khlong Phrae, Sai Ban Kraeo Noi ( Bang Kaeo ), km 8 on road branching E, 32 km of Ranong on rte to Kra Buri, 10.184N, 98.720E ; Songkhla drainage: ZRC 41974, 5 (1 adult, 4 juveniles), 36.4 mm, Ranong King, Amphae Suk Sam Lan (Ran), Ton Koi Waterfall, 9.353N, 98.430E ; ZRC 42184, 8 (5 adult, 3 juveniles), 18.5–23.1 mm, Ranong stream, N of Khura Buri, 100 km S of Ranong , 9.199N, 98.413E ; Panang Tak drainage: UF 236051, 4, 27.9–32 mm, Chumphon Province, Tha Sae Co., Panang Tak River at Khlong Rap Ro , 10.627N, 99.057E . Phuket Island: FMNH 124765, 2, 25.5–28.4 mm, Klong Vang In Nevi, (trib., Kra River ), rte. 4, 18 km from Kra Buri (52 km SW of Chumphon), 10.272N, 98.758E ; FMNH 124766, 1, 29.0 mm, Klong Chuitt, rte. 4090, 18 km NW of Pling, 8.588N, 98.398E; ROM 48972, 2, 27.7–31.3 mm, Ranong Province, N of Bang Kaeo, off highway 4 close to border of Burma, 10.250N, 98.750E ; SMF 3966 , 29.4 mm, holotype of Noemacheilus phuketensis , Phuket Island, off west coast of south peninsula Thailand, 7.992N, 98.343E ; SMF 3967 , 22.2 mm, paratype of Noemacheilus phuketensis , same locality as SMF 3966 ; SMF 4244 , 37.5 mm, paratype of Noemacheilus phuketensis , same locality as SMF 3966 ; UMMZ 238962, 2, 22–24.4 mm, Phuket, Nam Tok Ton Sai, 8.026N, 98.363E ; ZRC 45717, 8, 21–26.7 mm, Phuket, 7.957N, 98.317E . Gulf of Thailand: ZRC 42016, 1 , 23.6 mm, Prachaup Khiri Khan Province , Thaup Sakae District, W of Ang Thong, 11.449N, 99.483E .

Figures

FIGURE 5. Localities of examined specimens of Paracanthocobitis.

FIGURE 6. Holotype of Paracanthocobitis phuketensis, SMF 3966, Phuket Island, Thailand, 29.4 mm SL. Photo by F. Wicker (SMF).

FIGURE 7. Geographic variation in color pattern in Paracanthocobitis phuketensis. (A) ZRC 45717, Phuket Island, Thailand, 26.7 mm SL; (B) ZRC 46671, Nahkon Si Thammarat Province, Thailand, 27.8 mm SL; (C) ZRC 41974, Ranong Province, Thailand, 36.4 mm SL.