A new species of Ancistrus (Siluriformes: Loricariidae) from Tapajós and Xingu basins, Brazil

Abstract

A new Ancistrus species is described from Tapajós and Xingu river basins. It is distinguished from its congeners by the singular body color pattern, consisting of dark vermiculated stripes almost all over the body, and also by combination of features as a narrow head, large internostril distance, and absence of rows of enlarged odontodes on the lateral plates. In addition, the new species is distinguished from congeners that inhabit the rio Tapajós basin by the presence of a fully-developed adipose fin (vs. adipose fin absent in Ancistrus parecis and A. tombador, and vestigial adipose fin or absent in A. krenakarore). It differs from A. ranunculus, also from the rio Xingu, by the color pattern, smaller body size, smaller gill opening, and narrower cleithral width. The new taxon adds a new record to the list of species shared among the Xingu and Tapajós basins.

A new distinctively striped species of bushynose catfish (Siluriformes: Loricariidae: Ancistrus) from the Pachitea River drainage, Pasco, Peru

“…Ancistrus yanesha differs from all congeners, except A. centrolepis Regan, 1913, A. claro Knaack, 1999, and A. luzia Neuhaus et al, 2022, by having a color pattern of black vermiculated lines covering the head and two to four black parallel, lateral body stripes from head to caudal fin (vs. body uniformly colored or with dark or light spots or blotches over head and body). It differs from A. centrolepis , A. Claro , and A. luzia by dark body stripes never forming dots or vermiculations (vs. dark spots in A. centrolepis , dark vermiculations in A. claro and A. luzia ), from A. centrolepis by lateral plates lacking rows of enlarged odontodes (vs. lateral plates having enlarged odontodes in one to three crest‐like rows), from A. claro by having deeper caudal peduncle (11.9%–13.4% vs. 8%–10.7% SL), and from A. luzia by having longer dentary tooth cups (17.5%–22.2% vs. 8.8%–18% HL).…”

“…BMNH 1911.10.31.107–108, paratype, 1, 35.1 mm SL, Essequibo River, Guyana. Ancistrus luzia Neuhaus et al , 2022 . MNRJ 51458, male, 75.9 mm SL, holotype, Brazil, Mato Grosso State, Guarantã do Norte, rio Teles Pires basin, unknown stream next to bridge on road about 8 km from the road BR‐163, 9°47′15.00″S, 54°57′33.00″W.…”

“…Our objective here is to describe this species as new to science. Neuhaus et al (2022). Morphometrics are reported as percentages of standard length (SL), except for subunits of the head, which are reported as percentages of head length (HL).…”

“…With 76 currently valid species, the bushynose catfish genus Ancistrus Kner, 1854 is the fourth most species‐rich genus of catfish and the second‐most species‐rich genus in the suckermouth armored catfish family Loricariidae (Neuhaus et al, 2022). Ancistrus is distributed across most neotropical freshwaters between Panama and mid‐northern Argentina from sea level to over 1100 m asl (Fisch‐Muller, 2003; Fricke et al, 2023; Lujan & Armbruster, 2012).…”