Slate Pleco (Pseudancistrus genisetiger)

Slate Pleco — Pseudancistrus genisetiger
Dark armor with wild river character

The Slate Pleco is a rugged, river-built Loricariid known for its deep charcoal to slate-gray body accented with subtle lighter markings and textured armor plating. Unlike flashy spotted plecos, Pseudancistrus genisetiger carries a more understated, wild look — thick head, bristled odontodes, and a broad, powerful frame that gives it serious presence along the bottom of the tank.

Native to fast-moving, rocky South American rivers, this species is adapted to high oxygen and strong current. It spends much of the day wedged into wood and rockwork, emerging at feeding time or during low light to patrol its territory. Males develop more pronounced cheek odontodes and a heavier head structure as they mature, adding to their armored appearance.

Growing to around 8–12 inches, the Slate Pleco is large enough to hold its own in monster aquariums but manageable compared to the giant cactus plecos.

Aquarium Setup

• Minimum Tank Size: 125 gallons (180+ gallons preferred long-term)

• Substrate: Sand or smooth gravel

• Flow: Moderate to strong current

• Décor: Driftwood, rock caves, shaded areas

• Lighting: Moderate to dim

• Oxygen: High dissolved oxygen required

Tank Mates

Pairs well with robust species:

• Large cichlids

• Arowana

• Datnoids

• Bichirs

• Medium sized catfish

Avoid very small fish and extremely aggressive species that may harass it constantly.

Water Parameters

• Temperature: 75–82°F (24–28°C)

• pH: 6.0–7.5

• Hardness: Soft to medium

• Filtration: Strong biological filtration required

• Water Quality: Clean, well-oxygenated water essential

Diet

Omnivorous with strong protein preference:

• Sinking carnivore pellets

• Shrimp and mussel

• Insects / worms

• Occasional vegetable matter (zucchini, squash)