Editorial Type:
Article Category: Research Article
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Online Publication Date: 22 May 2015

Revision of the Zipper Loaches, Acanthocobitis and Paracanthocobitis (Teleostei: Nemacheilidae), with Descriptions of Five New Species

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Page Range: 378 – 401
DOI: 10.1643/CI-13-128
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Acanthocobitis was created by Peters in 1861 for a new species, A. longipinnis, from the Ganges River basin in India and has been treated over the past 150 years as a valid genus or as a synonym of Nemacheilus or Noemacheilus. A large number of names have been proposed for species that are morphologically similar, and presumably closely related, to A. longipinnis, with eight treated in recent publications as valid species (most with poorly understood geographic distributions), and 15 treated as synonyms. The present study examined morphological variation across the range of these forms, and diagnosed and mapped the distributions of valid species. Fifteen species are recognized in Acanthocobitis and the recently recognized Paracanthocobitis, including five newly described species and two removed from synonymy. Acanthocobitis is known from the Ganges and Brahmaputra basins of northern India and Bangladesh. Paracanthocobitis ranges from the Indus basin in Pakistan to the Mekong basin of Cambodia and Laos. A key is provided for identification of species.

Copyright: © 2015 by the American Society of Ichthyologists and Herpetologists
Fig. 1.
Fig. 1.

Acanthocobitis pavonacea (holotype of Acanthocobitis longipinnis, ZMB 4795). (A) Lateral view; (B) radiograph (photos by P. Bartsch).

Fig. 2.
Fig. 2.

Head of Acanthocobitis pavonacea (holotype of Acanthocobitis longipinnis, ZMB 4795). (A) Lateral view with suborbital flap; (B) ventral view showing papillated pad on either side of wide medial interruption in lower lip (photos by P. Bartsch).

Fig. 3.
Fig. 3.

Acanthocobitis pavonacea. (A) Live male, not preserved; (B) Cobitis pavonacea, SMF 9091, syntype, 121 mm, female; (C) Cobitis pavonacea, SMF 68, syntype, 95 mm female (photos by [A] S. Grant and [B, C] F. Wicker).

Fig. 4.
Fig. 4.

Snout morphologies in: (A) Acanthocobitis pavonacea, male (not preserved); (B) Paracanthocobitis maekhlongensis, UF 182864, female. Photos by (A) S. Grant and (B) authors.

Fig. 5.
Fig. 5.

Distributions of georeferenced specimens examined of: (A) Acanthocobitis pavonacea, (B) Paracanthocobitis abutwebi, (C) P. adelaideae, and (D) P. aurea, P. mooreh, and P. urophthalma. Syntypes of Cobitis pavonacea from Brahmaputra River are plotted arbitrarily at 26.091N, 90.206E. Holotype of A. longipinnis from Ganges River is plotted arbitrarily at 25.394N, 86.429E. Recent locality, Dibru River, Guijan, near Tinsukia, Assam, for P. pavonocea is from Grant (2007).

Fig. 6.
Fig. 6.

Ventral view of head of Paracanthocobitis maekhlongensis, UF 182864, 58.9 mm, showing papillated lips and large pad on either side of medial interruption in lower lip.

Fig. 7.
Fig. 7.

Suborbital processes in Paracanthocobitis. (A) Suborbital flap on P. adelaideae, USNM 378387; (B) suborbital groove (with no free posterior flap) on P. mandalayensis, CAS 88890.

Fig. 8.
Fig. 8.

Paracanthocobitis abutwebi. (A, B) Lateral and dorsal views, UMMZ 249907, holotype, 46.1 mm male.

Fig. 9.
Fig. 9.

Paracanthocobitis adelaideae. (A, B) Dorsal and lateral views, USNM 378387, holotype, 50.6 mm male; (C) USNM 378393, paratype, 28.5 mm juvenile.

Fig. 10.
Fig. 10.

Paracanthocobitis aurea, BMNH 1889.2.1.1590, lectotype of Nemacheilus aureus, 31.9 mm.

Fig. 11.
Fig. 11.

Paracanthocobitis botia. (A) BMNH 1889.2.1.1562, neotype, 45.3 mm male; (B) BMNH 1889.2.1.1563–1571, 57.7 mm female.

Fig. 12.
Fig. 12.

Distributions of georeferenced specimens examined of: (A) Paracanthocobitis botia, (B) P. canicula and P. maekhlongensis, (C) P. linypha, and (D) P. mackenziei. Neotype of P. botia is plotted on the Brahmaputra River at Goalpara (26.175N, 90.758E), India (re. Hora, 1929:318; 1935:49).

Fig. 13.
Fig. 13.

Paracanthocobitis canicula. (A) Dorsal view, UMMZ 234617, holotype, 63.4 mm male; (B) dorsal and (C) lateral views, ZRC 54207, paratype, 44.4 mm female.

Fig. 14.
Fig. 14.

Paracanthocobitis linypha. (A, B) Dorsal and lateral views, USNM 410754, holotype, 34.9 mm male; (C) lateral view, CAS 88918, paratype, 42.9 mm female.

Fig. 15.
Fig. 15.

Paracanthocobitis mackenziei, KU 29159, 67.1 mm male.

Fig. 16.
Fig. 16.

Paracanthocobitis maekhlongensis. (A, B) Dorsal and lateral views, NIFI 4853, holotype, 58.9 mm female; (C) lateral view, UF 182864, paratype, 56.4 mm female (photographed alive).

Fig. 17.
Fig. 17.

Paracanthocobitis mandalayensis. (A) Irrawaddy River basin, Myanmar, USNM 344646, 81.1 mm female; (B) Wang River basin, Thailand, UF 181110, 60.5 mm male and (C) 24.5 mm juvenile.

Fig. 18.
Fig. 18.

Distributions of georeferenced specimens examined of: (A) Paracanthocobitis mandalayensis, (B) P. pictilis, (C) P. rubidipinnis, and (D) P. zonalternans.

Fig. 19.
Fig. 19.

Paracanthocobitis mooreh, MCZ 52380, 44.4 mm male.

Fig. 20.
Fig. 20.

Paracanthocobitis pictilis. (A) UF 172927, 71.4 mm male; (B) UNMF-P 07667, 79.5 mm male.

Fig. 21.
Fig. 21.

Paracanthocobitis rubidipinnis. (A, B) Dorsal and lateral views, CAS 231191, 66.4 mm, Irrawaddy River at Magway; (C) lateral view, ZRC 43570, 55.5 mm female.

Fig. 22.
Fig. 22.

Paracanthocobitis urophthalma. (A) BMNH 1864.7.11.35–36, syntype, 48.8 mm male; (B) BMNH 1981.1.21.320, 33.4 mm female.

Fig. 23.
Fig. 23.

Paracanthocobitis zonalternans. (A) ZSM 27468, neotype, 33.1 mm male; (B) ZRC 41258, 36.1 mm male.

Fig. 24.
Fig. 24.

Paracanthocobitis mackenziei, KU 40459, 51.5 mm male. (A) Patch of adipose tissue along anterior portion of lateral line; (B) magnified view of patch.

Fig. 25.
Fig. 25.

Paracanthocobitis mackenziei, KU 40647, 42.6 mm, cleared and stained; arrows indicate first dorsal pterygiophore and enlarged neural spines.

Fig. 26.
Fig. 26.

Axillary pelvic process: absent in (A) P. abutwebi (UMMZ 249907), present in (B) P. maekhlongensis (NIFI 4853). Small vertical or crescent-shaped black blotch in ocellus of (C) P. pictilis (UNMF-P 07667), round black spot in ocellus of (D) P. maekhlongensis (NIFI 4853).

Fig. 27.
Fig. 27.

Variation in color pattern on side of body in species of Paracanthocobitis. (A) P. linypha (CAS 88918), (B) P. urophthalma (BMNH 1864.7.11.35–36), (C) P. abutwebi (UMMZ 208646), (D) P. botia (BMNH 1889.2.1.1563–1571), (E) P. adelaideae (USNM 378387), (F) P. mackenziei (KU 29159), (G) P. maekhlongensis (NIFI 4853), (H) P. rubidipinnis (ZRC 43570), (I) P. mandalayensis (UF 181110), and (J) P. canicula (UMMZ 234617).

Contributor Notes

Associate Editor: D. Buth.

Received: 11 Oct 2013
Accepted: 07 Oct 2014
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