Acanthicus adonis, the adonis pleco or polka dot lyre-tail pleco, is a large species of armored catfish.[1] It was originally described from the lower Tocantins River in Brazil, but individuals resembling the species have also been recorded from Amazonian Peru.[2] [3] The species is occasionally seen in the aquarium trade, but its massive adult size and territorially aggressive behavior means that a very large tank is required.[3] [1] These fish are opportunistic omnivores.[1]
Acanthicus adonis is among the largest armored catfish species and reaches a length of 1m (03feet).[1] [3]
It is dark brown to black with numerous white spots as a juvenile. As the fish matures, the spots become less numerous and smaller, often disappearing entirely in large adults.[1] [3] Its close relative A. hystrix always lack white spots, regardless of age.[2] [4] In contrast, A. adonis lacks the vermiculated pattern often (but not always) found on the underparts of A. hystrix.[2] [4]