Sucker fish

Sucker fish is a common name used for several kinds of fish, most often the freshwater fish in the family Catostomidae and, in some contexts, the remora.

Sucker fish is a common name used for several kinds of fish, most often the freshwater fish in the family Catostomidae and, in some contexts, the remora. Catostomid suckers are bottom-dwelling freshwater fishes with downward-pointing, suction-adapted mouths, while remoras are marine fish that attach to larger animals with a suction disk.

Taxonomy and name usage

Sucker fish is a broad common name rather than a single scientific classification. It most often refers to Catostomidae, but it is also used for remoras and other suction-using fish in popular contexts.

Physical characteristics

Catostomid suckers are cylindrical or robust freshwater fish with thick, downward-facing lips and a ventral mouth suited to feeding on bottom material. Remoras differ by having a suction disk on the head used to attach to larger animals.

Habitat and feeding

Catostomid suckers live mainly on the bottoms of lakes, rivers, and slow streams, where they feed on invertebrates, detritus, and plant matter. Remoras are marine fishes associated with larger hosts and feed on scraps and small organisms.

Distribution

Most suckers in the family Catostomidae are native to North America, with a smaller number of Asian species. The family is especially diverse in North America and is absent from some areas such as Newfoundland and Vancouver Island according to Canadian sources.

Aquarium and common-name confusion

In aquarium trade and popular writing, the name sucker fish is sometimes applied to plecos and other suckermouth catfish. These are different from catostomid suckers and belong to other fish families.