Hypancistrus undefined-1 Isbrucker & Nijssen 1991

Identification key to Hypancistrus species 1a. Body with pale blotches or spots on a dark background........................................... 2 1b. Body color pattern different from above.................................................................... 5 2a. Pale marks on head much smaller than on body ...................................... H. inspector 2b. Pale marks on head and body of similar size .............................................................. 3 3a. Pale marks equal to or larger than diameter of orbit .............................. H. contradens 3b. Pale marks smaller than diameter of orbit .................................................................. 4 4a. Pale marks similar in size to that of nasal aperture............................... H. margaritatus 4b. Pale marks less than half the size of nasal aperture................................... H. lunaorum 5a. Color pattern with dark spots, blotches or stripes on pale background ................. 6 5b. Color pattern with pale lines or bars on dark background...................................... 8 6a. Body milky white with wide oblique black bars on head and longitudinal stripes on body.................................................................................................. H. zebra 6b. Body tan with dark spots or blotches ......................................................................... 7 7a. Body with small dark isolated spots......................................................... H. phantasma 7b. Body with irregular dark-brown blotches, some coalescing to form large sinuous bars or saddles ................................................................................................... H. yudja 8a. Body covered with relatively few broad and wavy bars that alternate between dark and pale and are of similar widths .................................................... H. furunculus 8b. Body covered with pale wavy lines that are distinctly thinner than the dark adjacent areas .............................................................................................................. 9 9a. Body with many alternating dark and pale sinuous lines that are frequently anostomosed or interrupted into irregularly shaped bars; dorsal, pelvic and caudal fins with 6 to 10 dark bands similar in width to intervening pale bands .................................................................................... H. seideli 9b. Body dark with few thin pale lines that are sometimes interrupted and reduced to small isolated spots; dorsal, pelvic and caudal fins with 3 to 4 dark bands that are distinctly wider than intervening pale bands ..................................... H. debilittera