- Scientific name: Acanthicus adonis
- Common name: L-155 catfish, Polka Dot Lyre Tail Pleco
- Group: Catfishes
- Habitat: South America
- Size: 50 cm
- Biotope: Tributary of the Amazon at the Brazilian border to Peru.
- Social behavior: Acanthicus adonis should be kept separate, since it can be highly aggressive towards its own kind. Mature fish will be territorial so other catfish and plecos are not advised.
- Diet: Juveniles are herbivorous, it becomes more omnivorous as it matures; algae, tablet foods and small live foods.
- Breeding: Not known
- Tank: Minimum 400 litres
- Population: 1 fish for 400 litres
- Decoration: A tank as large as possible with current. Rockwork with caves and crevices. Intense illumination for algae growth. Background vegetation is possible, since it is not a plant eater. Use dark substrate.
- Temperature: 23-27 °C
- pH: 6-7
- Hardness: 5-16NK°
- Lifespan: 16 years
Description: The Acanthicus adonis are relatively slender,spiny catfishes. The caudal fin possesses long filamentous lobes on the upper and lower margins and is forked. The pectoral fin spines are extremely long, the entire dorsal surface of the head is covered in stout ,sharp odontodes. Males have more and longer cheek odontodes and greatly elongated odontodes on the pectoral fin spine. The color of Acanthicus adonis is typically black, sometimes gray. Juveniles have white spots over the whole body, which become bands on the caudal filaments, the adult lacks these white spots, but become jet black with maturity. When adult the pectoral fins can be in excess of 15 cm in length, giving a remarkable front profile. Most active at night.
A species tank is recommended, perhaps house them with small characins. In any case not together with any potential spawn eaters, as a breeding success of this catfish would be an aquaristic sensation. The animals seem to migrate during the spawning season. The animals could not be found a second time at the original locality. The fish only reach sexual maturity at several years of age.