Are Plecostomus Catfish Aggressive?

Plecostomus catfish (Hypostomus plecostomus), also called sucker catfish, are a popular aquarium fish due to their algae eating habits. Native to slow-moving waters of Central and South America, plecostomus catfish can grow up to 2 feet long in home aquariums. While they are docile as young fish, plecostomus catfish become more aggressive and territorial towards other catfish as they mature. However, a single plecostomus will live peacefully with other tropical fish that do not compete with the catfish for food. Large aquariums, proper decorations and diet help minimize aggression in plecostomus catfish.

  1. Description

    • Plecostomus catfish have a dark brown base color with black spots covering the body in a mottled pattern. The fish have a flat, lightly colored underside. Plecostomus catfish have a powerful mouth and strong jaws, which they use to scrap algae off of rocks, driftwood and glass in home aquariums. The specially developed mouth allows the fish to feed, breathe and remain anchored to the substrate at the same time. Plecostomus catfish have distinct eyes that appear cloudy during the day due to the presence of an omega iris, which limits the amount of light into the eye and helps camouflage the fish during the day.

    Aquarium Requirements

    • Plecostomus catfish are commonly sold as small fish less than 5 inches long and will survive well in small aquariums. However, the fish have a rapid growth rate and quickly become too large for aquariums less than 50 gallons and become highly aggressive towards other fish. Adult plecostomus catfish should be kept in large aquariums at least 50 to 100 gallons in volume to facilitate a peaceful fish community.

    Aquarium Landscaping

    • Plecostomus catfish are territorial fish and require a properly landscaped aquarium with plenty of aquarium furniture to develop healthily. Place artificial caves, flower pots or rocks in the aquarium to provide a place for the plecostomus catfish to rest and feel secure during the day. Driftwood should always be included in an aquarium landscape as well; plecostomus catfish need to chew on wood to aid their digestion and remain healthy in aquariums. Adding landscaping features to the aquarium increases the surface area for algae to grow on and the plecostomus catfish to feed on.

    Diet

    • Plecostomus catfish are omnivorous fish that require a varied diet in captivity. When young, algae that grows in the aquarium is sufficient to meet their nutritional needs. However, as the fish grow, they require supplemental feeding. Several types of specially formulated algae tabs are readily available for plecostomus catfish in captivity. Feed the fish at night to ensure that they get the tabs and not other fish in the aquarium. Supplement their diet with cooked vegetables such as cucumber, zucchini and lettuce. Feed large adult fish shrimp or earthworms every two weeks.