Catfish - Otocinclus/Dwarf Sucker (Otocinclus arnoldi)

Otocinclus are great algae eating fish. Because of their small size (4-5cm), they're the perfect clean-up crew for smaller tropical tanks. They will eat algae off your plants without causing any damage, but they will need their diet supplemented with algae wafers to keep them thriving. They're peaceful and don't hassle other fish.

Catfish (order Siluriformes) are a diverse group of fish. Named for their prominent barbels, which give the image of cat-like whiskers, they are found primarily in freshwater environments of all kinds.

Catfish have no scales. They possess a strong, hollow, bonified leading ray on their dorsal and pectoral fins, through which a stinging protein can be delivered if the fish is irritated. 

Catfish are often described as being nocturnal creatures; in other words they are most active at nighttime. In general terms catfish prefer to dwell at the bottom of an aquarium (or at the bottom of rivers, lakes, streams and creeks etc in their natural environments). 

Providing hiding places for them is of utmost importance. With careful planning of your aquarium layout you can not only provide your catfish with hiding places, but you will actually have the benefit of seeing them as well. Suitable materials to use for hiding places include wood, rocks, slate, clean plastic pipe and aquatic plants. 

Catfish generally are excellent tankmates for a wide variety of other species of fish.