Can Cory Cats & Otos Be in the Same Tank?

The various species of corydoras and otocinclus catfish are all peaceful tropical freshwater fish that can be housed in the same aquarium. The corydoras are termed armored catfish as they have substantial protective plates which cover their body. These interesting scavengers from the New World, and are relatively small catfish. Otocinclus catfish are if anything, smaller algae eating fish which enjoy the company of each and similar catfish types.

  1. Habitat Requirements

    • Corydoras and otocinclus catfish inhabit the soft, acidic waters of the Amazon Basin. Although these catfish prefer well oxygenated conditions, they are capable of gulping air from the surface of the water, if necessary. Both otocinclus and corydoras will rest on pieces of driftwood or on broad leafed plants between foraging sessions and should be provided with aquatic vegetation, aquarium décor or hollow logs to use as private retreats. Corydoras and otocinclus catfish are bottom dwelling species and can damage themselves if the substrate is too sharp. Despite these requirements, otocinclus and corydoras catfish are both hardy little scavengers and very compatible.

    Social Natures

    • Corydoras and otocinclus catfish are non-territorial algae eaters that are comfortable in the presence of either their own species or around other catfish types. Although otocinclus and corydoras form schools or groups, both of these catfish types require hiding and resting spots in the aquarium. Otocinclus and corydoras catfish do best in small groups, and as these little scavengers are so peaceful, groups can be made up of members from both catfish types. Corydoras and otocinclus catfish will mix readily when housed together and may feed or rest in close proximity to each other.

    Size Differences

    • All of the many corydoras catfish species are small, being between 1 and 7 inches long once mature. Most of the corydoras are under 4 inches in length, while the dwarf salt and pepper and pygmy corydoras are under 2 inches in length. The otocinclus catfish are also under 2 inches long, which places corydoras and otocinclus in a similar size range when compared to the huge plecostomus and other catfish species. This eliminates the danger of one species dominating or hurting the other.

    Behavior and Feeding

    • Both the corydoras and otocinclus catfish are principally active during the hours of darkness. These small scavengers spend most of their active time foraging for algae, which they will remove from the tank glass, substrate, aquatic plants and aquarium décor. Both groups will enjoy their algae meal to be supplemented with commercial sinking herbivore wafers and vegetables, such as blanched spinach.