Pseudolaguvia muricata, Heok Hee Ng, 2005

Heok Hee Ng, 2005, Two new species of Pseudolaguvia (Teleostei: Erethistidae) from Bangladesh., Zootaxa 1044, pp. 35-47 : 41-45

Pseudolaguvia muricata sp. nov.

(Fig. 3)

Glyptothorax sp. Rahman, 1989: 213.

Type material. Holotype: UMMZ 245581 , 22.6 mm SL; Bangladesh: Sylhet District, Rangapani Khal (creek), 6 km NNW of Jaintapur on Sylhet-Shillong highway , 25°10'N 92°6'E; W.J. Rainboth et al., 19 February 1978.

Paratypes: NRM 52292 (2), 20.9-21.5 mm SL; UMMZ 208655 (6), 20.5-23.2 mm SL; data as for holotype. UMMZ 208909 (1), 20.0 mm SL; Bangladesh: Rangpur District, Jabuneswari River just downstream from Badarganj ghat , 25°42'N 89°5'E; W.J. Rainboth & A. Rahman, 3 April 1978. UMMZ 208933 (8), 18.8-25.7 mm SL; ZRC 50382 (3), 21.2-22.6 mm SL; Bangladesh: Rangpur District, Ghaghat (Jagat) River, 7 km E of Rangpur on Badarganj road , 25°45'N 89°7'E; W.J. Rainboth & A. Rahman, 3 April 1978. CAS 222658 (2), 20.2-21.0 mm SL; UMMZ 208993 (5), 19.9-23.3 mm SL; Bangladesh: Dinajpur District, Tangam River at Thakurgaon, 200 m upstream from bridge on road to sugar refinery , 26°2'N 88°26'E; W.J. Rainboth & A. Rahman, 6 April 1978 .

Diagnosis. Pseudolaguvia muricata differs from congeners in having longer dorsal (21.2-26.7% SL vs. 14.3-21.7) and pectoral (26.8-35.7% SL vs. 15.9-23.3) spines. It can be further distinguished from P. foveolata in having a thoracic adhesive apparatus reaching beyond (vs. not reaching) the base of the last pectoral-fin ray, a shorter caudal peduncle (12.6-15.7% SL vs. 20.7) and fewer vertebrae (28-30 vs. 33); P. kapuri in having a shorter adipose-fin base (12.3-16.1% SL vs. 17.1-18.8); from P. ribeiroi in having a shorter caudal peduncle (12.6-15.7% SL vs. 16.4-18.2); and from P. inornata in having (vs. lacking) light brown patches on the body and a shorter caudal peduncle (12.6-15.7% SL vs. 16.3-19.0). Pseudolaguvia muricata further differs from P. shawi in lacking a color pattern of strongly contrasting brown and yellow bands and a larger interorbital distance (31.4-36.7% HL vs. 23.4-29.6); from P. tenebricosa in having a shorter caudal peduncle (12.6-15.7% SL vs. 16.9-18.9); and from P. tuberculata in having a shorter adipose-fin base (12.3-16.1% SL vs. 16.8-22.7) and caudal peduncle (12.6-15.7% SL vs. 16.2-20.1).

Description. Biometric data as in Table 2. Head depressed, body moderately compressed. Dorsal profile rising evenly from tip of snout to origin of dorsal fin, then sloping gently ventrally to end of caudal peduncle. Ventral profile flat to anal-fin base, then sloping gently dorsally to end of caudal peduncle. Supraoccipital spine reaching nuchal shield. Weberian lamina well developed, approximately same length as supraoccipital spine and extending parallel to either side of spine. Eye ovoid, horizontal axis longest; located entirely in dorsal half of head. Orbit with free margin. Gill openings narrow, extending from posttemporal to isthmus. Branchiostegal membranes united at isthmus. Caudal peduncle short and moderately slender. Anus and urogenital openings located at vertical through middle of adpressed pelvic fin. Skin prominently tuberculate, with conical tubercles particularly prominent on dorsal third of head and body. Lateral line complete and midlateral. Vertebrae 9+19=28 (4), 10+18=28 (10), 9+20=29 (1), 10+19=29 (11) or 10+20=30* (2). Abdomen with thoracic adhesive apparatus consisting of longitudinal, unculiferous ridges arranged in elliptical field and with prominent central median depression. Adhesive apparatus extending to midway between base of last pectoral-fin ray and pelvic-fin origin.

Mouth small, inferior and with papillate lips; upper jaw projecting beyond lower jaw. Oral teeth small and in irregular rows on all tooth-bearing surfaces. Premaxillary tooth band consisting of single broad lunate patch across midline; with conical teeth and not exposed when mouth is closed. Dentary tooth band narrow, with conical teeth.

Barbels in four pairs. Nasal barbel very short and broad, extending to midway between its base and anterior orbital margin. Maxillary barbel slender, with broad skin flap at base and extending to base of pectoral-fin spine. Outer mandibular barbel with broad skin flap on dorsal margin and extending to base of pectoral-fin spine; inner mandibular barbel broad and shorter, reaching to vertical through midway between posterior orbital margin and base of pectoral-fin spine.

Dorsal fin located about two-fifths along body; with 4,i (17) or 5* (11) rays and straight margin. Dorsal-fin spine long, flattened, slightly curved and robust; spine extending to line through base of first anal-fin ray. Anterior margin of spine with 8-12 low serrations, posterior margin with 6-10 serrations.

Pectoral fin with stout, blade-like spine, sharply pointed at tip, and with 5,i (10) or 6* (18) rays. Anterior spine margin with 14-18 small serrations. Posterior spine margin with 9-13 serrations. Pectoral-fin margin straight anteriorly and posteriorly. Coracoid with moderate posterior processes, extending to midway between base of last pectoral-fin ray and pelvic-fin origin.

Pelvic-fin origin at vertical through base of last dorsal-fin ray. Pelvic fin with i,5 (28) rays and straight margin; tip of adpressed fin not reaching anal-fin origin.

Adipose fin short, posterior end deeply incised. Fin located above anal-fin base. Anal fin with iv,6 (26) or iv, 7* (2) rays, and straight anterior and slightly convex posterior margin.

Caudal peduncle moderately slender. Caudal fin deeply forked, with i,7,7,i (28) principal rays; upper and lower lobes pointed, with lobes of equal length but lower lobe slightly broader than upper. Procurrent rays symmetrical, extending only slightly anterior to fin base.

Coloration. In 70% alcohol: dorsal and lateral surfaces of head and body medium to dark brown, fading to lighter brown on lateral surfaces of head and ventral surfaces of head and body. Faint dark line running from anterior orbital margin to tip of snout. Two series of light brown markings on body: first consisting of paired light brown spots above and below lateral line between dorsal and adipose fins, coalescing to form incomplete transverse band in some individuals and second consisting of transverse band on anterior half of caudal peduncle. Light brown markings indistinct in some individuals. Dorsal fin brown, with irregular distal hyaline band. Adipose fin brown, with irregular hyaline distal margin. Pectoral and anal fins hyaline, with brown melanophores forming irregular transverse bands at base and subdistally. Pelvic fins hyaline, with brown melanophores forming irregular transverse bands subdistally. Caudal fin brown at base of lobes, hyaline throughout much of lobe and with scattered brown melanophores; moderately broad, transverse subdistal brown bands present near tips of lobes. Maxillary and all mandibular barbels light brown, annulated with brown rings, nasal barbels brown dorsally, light brown ventrally.

Distribution and habitat. Known from the Brahmaputra River drainage in Bangladesh (Fig. 2).

The type locality of P. muricata is a clear, shallow, slow-flowing stream with a mixed substrate of sand and detritus, with the fish being found amongst detritus in areas with current. Other fish species collected at this locality were: Barilius barna (Cyprinidae), Barilius bendelisis (Cyprinidae), Barilius tileo (Cyprinidae), Devario devario (Cyprinidae), Oreichthys cosuatis (Cyprinidae), Psilorhynchus sucatio (Psilorhynchidae), Lepidocephalichthys guntea (Cobitidae), Acanthocobitis botia (Balitoridae), Schistura corica (Balitoridae), Schistura savona (Balitoridae), Amblyceps mangois (Amblycipitidae), Mystus bleekeri (Bagridae), Olyra longicaudata (Bagridae), Conta conta (Erethistidae), Hara jerdoni (Erethistidae), Pseudolaguvia ribeiroi (Erethistidae), Pseudolaguvia shawi (Erethistidae), Aplocheilus panchax (Aplocheilidae), Xenentodon cancila (Belonidae), Microphis deocata (Syngnathidae), Chanda nama (Ambassidae), Parambassis baculis (Ambassidae), Parambassis ranga (Ambassidae), Channa gachua (Channidae), Ctenops nobilis (Osphronemidae), Badis badis (Badidae), Nandus nandus (Nandidae), Glossogobius giuris (Gobiidae), Mastacembelus pancalus (Mastacembelidae) and Tetraodon cutcutia (Tetraodontidae).

Etymology. From the Latin muricata, meaning spiny (like a murex), in reference to the elongate dorsal and pectoral-fin spines of this species. Used as an adjective.