Pseudolaguvia inornata, Heok Hee Ng, 2005

Heok Hee Ng, 2005, Two new species of Pseudolaguvia (Teleostei: Erethistidae) from Bangladesh., Zootaxa 1044, pp. 35-47 : 36-40

Pseudolaguvia inornata sp. nov.

(Fig. 1)

Glyptothorax sp. Rahman, 1989: 214.

Pseudolaguvia tuberculata (non Prashad & Mukerji) de Pinna, 1996: 8.

Type material. Holotype: UMMZ 245580 , 25.8 mm SL; Bangladesh: Chittagong District, Koilla Khal (creek), 10 km E of Feni-Chittagong highway on road to Ramgarh , 22°55'N 91°36'E; W.J. Rainboth et al., 3 February 1978.

Paratypes: UMMZ 209010 (3 alc., 1 c&s), 25.2-27.4 mm SL; data as for holotype .

Diagnosis. Pseudolaguvia inornata differs from congeners in having a uniform brown body with a pale mid-dorsal stripe and without any pale patches (vs. brown body without pale mid-dorsal stripe and with yellow bands or light brown patches) and the caudal fin lobes with brown submarginal stripes running along the entire length (vs. transverse brown bands near the tips). 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 deeper body (13.9-16.1% SL vs. 11.0) and fewer vertebrae (29-30 vs. 33); P. kapuri in having a shorter adipose-fin base (13.6-16.4% SL vs. 17.1-18.8); from P. muricata in having shorter dorsal (18.7-21.7% SL vs. 21.2-26.7) and pectoral (20.4-23.3% SL vs. 26.8-35.7) spines and a longer caudal peduncle (16.3-19.0% SL vs. 12.6-15.5); and from P. ribeiroi in having a longer dorsal-fin spine (18.6-21.7% SL vs. 14.2-17.9) and deeper caudal peduncle (7.7-8.5% SL vs. 6.6-7.2). Pseudolaguvia inornata further differs from P. shawi in having a larger interorbital distance (30.4-34.2% HL vs. 23.4-29.6), from P. tenebricosa in having a longer dorsal-fin spine (18.6-21.7% SL vs. 15.8-17.3) and from P. tuberculata in having a shorter adipose-fin base (13.6-16.4% SL vs. 16.8-22.7).

Description. Biometric data as in Table 1. 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 of moderate length and depth. 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 10+19=29 (2) or 11+19=30* (3). 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 middle of orbit.

Dorsal fin located about two-fifths along body; with 4,i (1) or 5* (4) rays and straight margin. Dorsal-fin spine flattened, straight and robust; spine extending to line through base of pelvic fin. Anterior margin of spine smooth, posterior margin with 4-6 small serrations.

Pectoral fin with stout, blade-like spine, sharply pointed at tip, and with 5,i (1) or 7* (4) rays. Anterior spine margin with 16-18 small serrations. Posterior spine margin with 8-9 large serrations. Pectoral-fin margin straight anteriorly and posteriorly. Coracoid with short posterior processes, extending just beyond base of posteriormost pectoral-fin ray. Pelvic-fin origin at vertical through middle of dorsal-fin base. Pelvic fin with i,5 (5) 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 iii,7* (2), iv,6 (1) or iv,7 (2) rays, and straight anterior and posterior margins. Caudal peduncle moderately deep. Caudal fin deeply forked, with i,7,7,i (5) 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 brown, fading to light brown on lateral surfaces of head and dorsal and lateral surfaces of head and body. Faint dark line running from anterior orbital margin to tip of snout. Light brown stripe running along supraoccipital spine and continuing along nuchal shield and anterior edge of dorsal spine. Lateral tips of nuchal plates with light brown spots. Light brown band running mid-dorsally between dorsal and adipose fins and extending along dorsal margin of adipose fin. Dorsal fin brown, with irregular hyaline margin distally. Pectoral and pelvic hyaline, with scattered melanophores. Anal fin hyaline, with brown along base and irregular brown stripe running along length of first and second branched anal-fin rays. Caudal fin hyaline, with subdistal brown stripe running along length of each lobe. Nasal and maxillary barbels brown dorsally, light brown ventrally; all mandibular barbels light brown.

Distribution and habitat. Known from the type locality in the Feni River drainage in Bangladesh (Fig. 2). The Feni River debouches into the Bay of Bengal to the east of the mouth of the Ganges-Brahmaputra system, and drains the western end of the Chittagong Hill Tracts.

Pseudolaguvia inornata was collected from a clear, shallow, moderately flowing stream with a predominantly sandy bottom. Devario devario (Cyprinidae) and Batasio batasio (Bagridae) were collected along with P. inornata .

Etymology. From the Latin inornatus, meaning unadorned, in reference to the absence of pale markings on the sides of the body in this species. Used as an adjective.