The ornate rubbernose pleco (Siluriformes, Loricariidae, Chaetostoma), a new species from the Ucayali River Basin, Peru

A new species in the rubbernose catfish genus Chaetostoma is described from the Aguaytia, Pisqui and Palcazu Rivers, which drain the Pampa de Sacramento Region in the Ucayali River drainage of central Peru. The new species is distinguished from congeners, except C. anomalum , C. branickii , C. dorsale , C. leucomelas , C. microps , C. nudirostre , C. palmeri and C. thomsoni by having distinct, white, variably-shaped spots or vermiculations ½–2× nostril diameter on dark grey to black background on the head (vs. spots absent or black on light-coloured background). The new species is distinguished from C. anomalum , C. branickii , C. dorsale , C. microps , C. nudirostre and C. thomsoni by having highly variable, distinct white spots, vermiculations or bands ½–10× nostril diameter on the body, from C. leucomelas by having dorsal and caudal fin indistinctly and variably-patterned with zero to four bands (vs. dorsal and caudal fin consistently having five or more uniform bands) and from C. palmeri by having two predorsal plates (vs. three), supraoccipital excrescence present (vs. absent) and pelvic-fin insertion slightly posterior to dorsal-fin insertion (vs. pelvic-fin insertion at middle of dorsal-fin base). Species delimitation analyses of the COI and Cytb genes further support the recognition of this new species.