Ancistrus mullerae Bifi, Pavanelli & Zawadzki 2009

This species differs from its congeners in the Río de La Plata and coastal basins of southern Brazil, except A. abilhoai, A. agostinhoi, A. formoso, A. multispinis and A. taunayi, by possessing a maxillary barbel short and not free from lower lip (vs. longer and free from lower lip); from A. abilhoai by the width of its mandibulary teeth row 16.5-21.0% of HL (vs. 13.4-15.5%) and 39.3-58.0% of interorbital width (vs. 32.9-37.9%); from A. agostinhoi by occipital depth 15.4-18.8% of SL (vs. 18.8-22.0%) and head length 34.4-37.9%, mean= 36.3% of SL (vs. 37.8-41.4%, mean= 38.9%); from A. formoso by orbital diameter 11.9-18.4% of HL (vs. 8.3-8.7%), caudal peduncle depth 8.8-11.5% of SL (vs. 7.8-8.7%) and number of dentary teeth 51-97 (vs. 110); from A. multispinis and A. taunayi by number of interopercular spines 12-22 (vs. 24-35 and 22-28, respectively) (Ref. 83296).

Dorsal spines (total): 1; Dorsal soft rays (total): 7; Analspines: 1; Analsoft rays: 3 - 4

Ancistrus mullerae is a species of catfish in the family Loricariidae. It is native to South America, where it occurs in the Iguazu River basin in the state of Paraná in Brazil. The species reaches 12.5 cm (4.9 inches) SL. It was described in 2009 by A. G. Bifi, C. S. Pavanelli, and C. H. Zawadzki, alongside two other species in the genus Ancistrus from the same river basin: A. abilhoai and A. agostinhoi.