Sucker fish are algae eaters often kept in home aquariums to keep the tank walls clean and free of algae slime. A variety of sucker fish are offered in the pet trade, although some grow too large to be practical in home aquariums. Smaller species of sucker fish are usually the best bet for controlling algae.
Loricariidae Family: Armored Catfish
Within family Loricariidae, the Hypostomus genus is the largest, with some 130 members. The common pleco, also called the suckermouth catfish, is part of this genus. Besides algae, this South American native also eats small crustaceans. He has a tall dorsal fin, and his large head is broad and flat.
Bushy Nose Pleco
The bushy nose or bristlenose pleco is one of the most common algae eaters you can buy. His stout brown body grows to 4 1/2 inches; his face is covered with whiskerlike feelers. These fish need lots of green foods -- not just algae but also blanched veggies and flake food. A 30-gallon community aquarium makes a good home.
The whiptail or twig catfish has a long nose and a skinny brown body covered with plates. He grows to 6 inches long and resembles a stick. He eats most species of algae and can live in community tanks of 50 gallons or larger -- flake food and blood worms supplement his diet. This catfish gets along well with tetras, hatchets and pencil fish, but cichlids and barbs may try to kill the whiptail.
The otocinclus catfish grows to only 2 inches and thrives in a highly filtered 30-gallon tank. He's social and gentle, and does best in schools of his own kind. He'll eat vegetable flake food or wafers when algae is scarce.
The Loricariidae family of catfish includes more than 650 species. Many of the most popular sucker fish for aquariums come from this family. These armored catfish are covered with bony plates to protect them and have sucker mouths. They naturally live in fast-flowing lowland streams in South America, Costa Rica and Panama. They require rock shelters or driftwood on the tank bottom, lots of plants, and water that's highly aerated and that maintains a slight current.
Gyrinocheilidae Family: Algae Eaters
Chinese Algae Eater
The Chinese algae eater has a slender golden-brown body with a dark horizontal stripe. Also known as the sucking loach or honey sucker, he grows up to 10 inches long and needs a tank of at least 30 gallons, furnished with rocks, driftwood and plants to hide in. Less peaceful than other sucker fish, this guy can get aggressive and defensive as he grows. He eats mainly algae, so if his tank is clean, he needs algae wafers to get by.
The Gyrinocheilidae family of fish is another family of algae eaters. Found mainly in mountain streams in Southeast Asia, these fish have no teeth and suctorial mouths for attaching to objects. They grow to 12 inches long and eat only algae, so they make good aquarium fish for tanks of moderate size.
Cyprinidae Family: Minnows and Carps
Siamese Algae Eater
The Siamese algae eater is a hardy, thin black-and-white striped fish that many aquarium enthusiasts insist on having in community tanks. He grows to 6 inches and does well in a small aquarium of at least 30 gallons with plenty of broad-leafed plants and rocks. Water should be highly aerated and kept between 75 and 79 degrees Fahrenheit. He gets along nicely with other fish and needs flake food, blood worms, pellets and vegetables to supplement his algae eating.
The Cyprinidae family consists of more than 3,000 species of minnows and carps who are native to the fresh waters of North America, Eurasia and Africa. They have one to three rows of teeth but usually not more than eight teeth all together. Their lips are usually thin but can be suckerlike in certain species.
Catostomidae Family: Suckers
Catostomidae suckerfish are a family of about 80 species. They hail from North America, China and Siberia. Like carp and some other fish, they have a row of pharyngeal teeth -- at least 16 of them. He also has thick lips on the bottom of his head that he attaches to rocks at the bottom of the river. Besides algae he also eats small fish, crustaceans, worms and insects. These fish, including white suckers, hog suckers, carpsuckers, Chinese suckers, and smallmouth and bigmouth buffalo, are often seen in streams but rarely found in home aquariums.
Echeneidae Family: Remoras
Remoras are a family of sucker fish scientifically known as Echeneidae, which has fewer than 10 member species. Commonly known as shark suckers, their spiny dorsal fins have evolved into flat, oval-shaped, serrated sucking plates on top of their heads. Remoras have slender bodies, soft dorsal fins and small, pointed teeth with underbite. These seawater fish use their sucking plates, or sucking disks, to attach to the undersides or gills of larger fish, sharks, rays and sea turtles. They're found in the Pacific, Atlantic and Indian oceans. You can encounter these fish while diving, and they're often used as fishing bait, but they're not common aquarium fish.