Ancistrus reisi Fisch-Muller, Cardoso, da Silva & Bertaco 2005

Distinguished from all congeners except Ancistrus tombador and A. jataiensis by the absence of an adipose fin. Adipose fin is replaced by a series of 2 to 4 median unpaired platelets forming a low crest. These platelets are nearly immediately followed by the plate-like procurrent caudal rays, while in A. tombador these are followed by at least two lateral plates that join dorsally before the procurrent caudal rays (Ref. 54498). Distinguished from A. tombador by following characters: snout with naked margin generally ill-delimited by posterior dermal plates which are irregular in size and shape and rarely joined together; tentacles present, unbranched; body wider (cleithral width 31.6-34.5% SL, mean 33.1) and caudal peduncle depth 9.6-10.7% SL, mean 10.2. Differs from A. jataiensis by the following morphometric characters: predorsal length (43.8-46.4% SL, mean 44.9, vs. 47.5-49.3% SL, mean 48.1), occipital depth (14.9-17.0% SL, mean 16.0, versus 17.0-19.5% SL, mean 18.1) and caudal peduncle length (27.7-30.9% SL, mean 28.7, vs. 24.6-27.1%SL, mean 26.3) (Ref. 54498).Description: D i,7; P i,6; V i,5; A i,4; C i,13,i or more generally i,14,i (Ref. 54498).

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

Found in small rivers (Ref. 54498).

Ancistrus reisi is a species of catfish in the family Loricariidae. It is a freshwater fish native to South America, where it is known to occur in small rivers in the state of Tocantins in Brazil. The species reaches 6.1 cm (2.4 inches) SL and is distinguished from most members of the genus (except A. tombador and A. jataiensis) by the absence of an adipose fin, which for this species is replaced by a series of unpaired platelets that form a low crest.