Lyretail Pleco

Geographic Origin and Biotope: Endemic to the Amazon River basin (Brazil, Peru, Ecuador). Robust species that thrives in turbid and fast rivers, taking refuge in submerged logs or under rocky cliffs during the day.

Taxonomy and Morphology: Lyretail Pleco (L155 / Acanthicus hystrix). An aquatic "monster" in every sense. Slender shape with caudal lobes that extend into infinite filaments (Lyretail). The body is completely armored and entirely covered with quills ("hystrix" = porcupine).

Social Behavior: Territorial and asocial, especially towards other bottom fish. As it grows, it will develop a marked aggressiveness, attacking and fatally injuring intruders with vigorous strokes of its tail armed with odontodes.

Coloration and Sexual Dimorphism: Juvenile specimens can present a blackish background with elegant white spots, but mutate into a solid coal black as adults. Massive males, with extremely developed and dangerous opercular (cheeks) and pectoral odontodes.

Aquarium Setup: Cyclopean dimensions (over 250 cm / 100 inches tank) for adults. Setup with enormous glued smooth boulders and giant logs (nothing that can be overturned). Do not use internal glass heaters: it will shatter them.

Diet and Feeding: Tireless omnivore. Mixed and massive diet: zucchini, sweet potatoes, fruit (melon), peas, balanced with a strong protein intake from white fish fillets, mussels, shelled shrimp and XL pellets.

Water Quality: Produces impressive droppings, proportionate to its size. Industrial filtration systems (huge sumps) and weekly 50% water changes are mandatory. Requires vigorous current and saturation oxygen.

Compatibility and Tankmates: Can only be paired with very large South American fish that occupy the upper water column: Arowana (Osteoglossum), large Cichla (Peacock Bass), or Pacu (Colossoma). Will kill other large plecos in non-gigantic tanks.

Aquarium Reproduction: Never documented due to inaccessible dimensions and aggressiveness in private tanks. Reproduction occurs in nature in deep rocky crevices flooded during the rainy season.

Risks and Diseases: The greatest danger is for the aquarist: handling it barehanded leads to deep lacerations. Under stress or due to poor water quality it can develop severe bacterial infections that affect the filamentous fins.