Pseudotothyris janeirensis Britski & Garavello 1984

Pseudotothyris janeirensis is distinguished from all congeners by possessing dorsal-fin spinelet (vs. absent); transverse dark saddles on the dorsum absent (vs. present); subocular cheek plate always absent (vs. generally present); and odontodes on lateral plates aligned in well-defined series (vs. randomly distributed). It can be diagnosed from Pseudotothyris obtusa by havingabdomen almost entirely naked, except for one to three lateral abdominal plates and one to two preanal plates (vs. abdomen partially or totally covered by scattered plates); 31-35 teeth on upper pharyngeal toothplate (vs. 20-30); and 18-23 teeth on ceratobranchial 5 (vs. 12-15 ). It differs differs from Pseudotothyris ignota by having the anterior margin of snout completely covered by odontodes (vs. anterior margin of snout with an odontode-free band) (Ref. 116384).

Dorsal soft rays (total): 8 - 9; Analsoft rays: 5 - 6; Vertebrae: 28

Collected from a lentic environment, regionally known as açude, a kind of water reservoir. It is uncommon for Pseudotothyris and for the majority of the members of Hypoptopomatinae to occur in this type of habitat (Ref. 116384).

Pseudotothyris janeirensis is a species of armored catfish endemic to Brazil, where it is found in Rio de Janeiro. This species grows to a length of 5 centimetres (2.0 in) SL.