You’ve likely seen some type of fish cling to the side of the aquarium with a suction mouth. Most of these fish belong to the Loricariidae family.
What is a sucker fish?
Members of the Loricariidae family can sometimes be referred to as sucker fish, sucker mouth catfish, or armored catfish. There are currently almost 100 different genera of these fish and over 680 defined species. Some sucker fish are categorized under an “L number” naming system because their true taxonomic description has not yet been established and / or accepted.
Members of Loricariidae can usually be identified by their flattened, bony body and characteristic suction mouth on their underside. They can come in a variety of colors and appear to be an attractive addition to many freshwater tanks, though their size and demanding appetites make them more difficult to keep successfully.
Some of the most common species found in the aquarium trade are the pleco (Hypostomus plecostomus), the royal pleco (Panaque nigrolineatus) and the bristle pleco (Ancistrus sp.).
How big do suckers get?
Sucker fish are known for their ability to quickly outgrow a tank despite their slow growth rate. Species of Loricariidae can range from less than 2.5 cm in size to 100 cm in length.
Because of their size, most species are not kept in typical freshwater tank superstructures, and many must be transferred to ponds as they grow.
What do suckers eat?
Sucker fish are mostly omnivores, with some related species even relying on wood as a dietary supplement. These fish live on the bottom of the substrate and use their suction cups to scrape off algae and biofilm from surfaces. However, you can also use these suction cups to tear off the flesh of rotting fish and other invertebrates.
While these fish are usually not aggressive in the tank, if they find food, they won’t hesitate to eat. These fish have a very good sense of smell and raised taste buds so it is usually not a problem for them to follow smells as they are carried through the water!
How long do sucker fish live?
Sucker fish can live for a long time under optimal tank and water conditions. Some related species have been reported to live for over a decade and sometimes even hit the 20 year mark.
Unfortunately, there is a lot of misinformation out there about sucker fish. They are often sold as primarily algae eaters, staying under 5 inches when fully grown. This is incorrect and each Loricariidae has its own requirements and tank preferences.
Always make sure that you research the type of fish or invertebrates you plan to add to your aquarium to make sure they will fit perfectly!