Pseudancistrus kayabi Silva, Roxo & Oliveira 2015

Pseudancistrus kayabi is distinguished from all congeners except P. reus by having dark bars in caudal and dorsal fins (vs. with white spots in caudal and dorsal fins). It can be further diagnosed from all Pseudancistrus except P. nigrescens by having a dark brown body with whitish spots that fade along the posterior portion of the dorsal fin and forming mottled pattern (vs. either dark brown with conspicuous rounded spots not covering more than one plate in P. barbatus, P. corantijniensis, P. depressus, P. asurini, and P. zawadzkii or with dark brown bars in P. reus). It further differs from P. barbatus and P. depressus by having the snout with yellowish hypertrophied odontodes (vs. reddish-brown odontodes). Other characters useful for the identification of P. kayabi include the following: shorter pectoral spine, 22-30% SL (vs. 29-34% in P. nigrescens, 31-33% in P. zawadzkii, and 30-34% in P. barbatus); shorter dorsal-fin base, 20-28% SL (vs. 28-29% in P. nigrescens, 29-31% in P. zawadzkii, and 28-31% in P. barbatus); greater internares width, 13-19% HL (vs. 10.5-12.9% in P. nigrescens); head depth, 60-66% HL, greater than in P. nigrescens (56-57%) and in P. barbatus (41-53%) but smaller than in P. zawadzkii (67-73%); and a greater adipose-anal distance (17-25% SL vs. 15-17% in P. nigrescens and 12-15% in P. barbatus) (Ref. 99871).

Dorsal spines (total): 1; Dorsal soft rays (total): 7; Analspines: 1; Analsoft rays: 5

Pseudancistrus kayabi is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Teles Pires River, which is part of the Tapajós basin in the state of Mato Grosso in Brazil. The species reaches 8.8 cm (3.5 inches) SL. Its specific epithet, kayabi, refers to the Kayabí people who historically inhabited the region surrounding the Teles Pires, Arinos, and Dos Peixes river basins in Mato Grosso. It was described in 2015 by Gabriel S. C. Silva, Fábio F. Roxo, and Claudio Oliveira alongside the related species Pseudancistrus asurini from the Xingu River basin.