Archolaemus janeae Vari, de Santana & Wosiacki 2012

Distinguished by the following combination of characters: gape relatively long, the rictus falling short posteriorly of the vertical through the posterior naris; the anteroposterior length of premaxilla equal to the transverse width; teeth on the dentary occupying most of the dorsal margin; two or three teeth arranged in a single row on the internal surface of the endopterygoid; 15-17 scales above the lateral line at the midbody; the length of the coronomeckelian bone less than 20% the length of Meckel’s cartilage; length of theposterior ceratohyal 1.5 times the length of the ventral hypohyal; the length of the caudal filament 16.0-25.7% LEA; depth of the caudal filament 5.6-11.2% CL; presence of a narrow dark stripe along the lateral line and a broad band of dusky to dark pigmentation overlying the basal pterygiophores of the anal fin; 19-21 pectoral-fin rays; 205-228 anal-fin rays; headlength at the opercle 13.5-14.7% LEA (Ref. 93148). Description: anal fin with 22-33 unbranched rays and 205-228 total fin rays; pectoral-fin rays ii, 19 to ii, 21 (Ref. 93148).

Analsoft rays: 205 - 228

Collected in river with pronounced current that was faster towards the centre of the channel, with the substrate in the sampled areas formed by pebbly sand. Also found in the main stream of shallow rapids and small waterfalls, always over a rocky bottom (Ref. 93148).

Archolaemus janeae is a species of glass knifefish endemic to Brazil where it is found in the Rio Xingu and upper Rio Tapajós, Amazon basin. This species reaches a length of 40.2 cm (15.8 in).