Anostomoides Pellegrin, 1909

Assega, Fernando Massayuki & Birindelli, José Luís Olivan, 2019, Taxonomic revision of the genus Anostomoides (Characiformes: Anostomidae), Zootaxa 4646 (1), pp. 124-144 : 126-127

Genus Anostomoides Pellegrin

Anostomoides Pellegrin 1909: 346 . Type species: Anostomoides atrianalis Pellegrin 1909 . Type by monotypy. Gender: masculine.

Diagnosis. The genus Anostomoides is diagnosed among Anostomidae by having the following combination of non-exclusive features: mouth upturned or slightly upturned with four teeth on premaxillary ( Fig. 2 ), including symphyseal tooth unicuspid or bicuspid (never tricuspid), remaining teeth slightly tricuspid (with medial cuspid distinctly larger); four dentary teeth, symphyseal tooth with truncate cutting edge (without cusps); second tooth unicuspid, and two lateral teeth with small cusps (three or slightly more cusps) ( Fig. 3 ); lower jaw lip with dermal papillae either rounded or forming ridges. See Discussion for comparisons with other genera.

Distribution. The species of Anostomoides are distributed in the Amazon, Essequibo, and Orinoco basins and their tributaries, in Brazil, Bolivia, Colombia, Guyana, Peru, and Venezuela.

Figures

FIGURE 2. Lateral view of head showing the position of the mouth, upturned (A and C), slightly upturned (B) and terminal (D). (A) Anostomoides atrianalis, ANSP 182467, 128.3 mm SL, Peru, Loreto, Río Nanay; (B) A. nattereri, LIA 1229, 175.5 mm SL, Brazil, Pará, Rio Xingu; (C) Laemolyta proxima, MZUEL 17132, 215.5 mm SL, Brazil, Amazonas, Manaus; (D) Leporinus fasciatus, MZUEL 14698, 136.3 mm SL, Brazil, Amazonas, Rio Negro. Scale bar = 10 mm.

FIGURE 3. Scanning electron microscope image of left upper and lower jaws of Anostomoides: (A) A. atrianalis, INPA 15193, 137.2 mm SL; (B) A. nattereri, MZUSP 5429, 89.0 mm SL.