Hypostomus levis (Pearson 1924)

Jonathan W. Armbruster, 2003, The species of the Hypostomus cochliodon group (Siluriformes: Loricariidae)., Zootaxa 249, pp. 1-60 : 35-36

Hypostomus levis (Pearson 1924)

(Fig. 15)

Rhinelepis levis Pearson 1924 : 22-23, pl. 5 figs. 1-3.

Material examined: BOLIVIA. La Paz: Río Cochabamba, Río Beni dr. Huachi, at junction of Río Bopi and Río Cochabamba, CAS 77349, 1, (152.9), Holotype and CAS 77350, 2, (115.0-150.8), Paratypes: Río Popoi, Río Beni dr. CAS 56747, 2, 1 cs, (77.1-92.2) and UMMZ 66492, 1, (57.6).

Diagnosis: Hypostomus levis can be separated from all other members of the H. cochliodon group by the lack of an adipose fin.

Description: See Hypostomus cochliodon group description for more details. Morphometric data given in Table 3. Available specimens probably faded considerably; light brown; pectoral and pelvic fins and occasionally head spotted; spots absent elsewhere except for some faint ones in dorsal fin. Abdomen considerably lighter than sides, without spots. Caudal fin with dark wash distally, base of caudal fin significantly lighter than distal margin.

Dorsal fin short. Adipose fin and pre-adipose plate absent. Depressed pectoral-fin spine ventral to pelvic fin reaches beyond bases of pelvic-fin rays.

Keels absent; lateral plates almost perfectly smooth. Orbits forming slight ridge slightly raised above medial surface of head; ridges of dorsal and lateral aspect of head fairly smooth. Longitudinal ridge on pterotic-supracleithrum beginning at posterodorsal corner of eye formed from raised bone and slightly larger odontodes absent. Opercle usually supporting no odontodes, but occasionally with one or two odontodes present. Presence of unique nuptial body odontodes (Fig. 2B) in H. levis unknown (see Discussion below). Plates in skin anterior to dorsal-fin spine absent in specimens examined.

Each jaw with 11-17 teeth (mode = 14), teeth relatively small, but distinctly spoonshaped(Armbruster & Page 1997). Average angle between dentaries 63° (SD = 9°; range: 53°-68°; N=3). Lateral line plates 28-30; dorsal plates 8; dorsal-caudal plates 16-18.

Range: Only known from the Ríos Cochabamba and Popoi of the upper Río Beni - Upper Río Madeira drainage of Bolivia (Fig. 8). Hypostomus levis is allopatric to all other members of the H. cochliodon group, but is potentially sympatric with H. pyrineusi .