What would you get if you combined a ping pong ball, a suction cup and a fish? A lumpsucker.

Lumpsuckers are a group of small, spherical fish that live in the chilly waters of the Arctic, North Pacific and North Atlantic. They’re part of the Cyclopteridae family, which gets its name from the Greek words “kyklos”, meaning “circle” or “round”, and “pteryx” meaning “fin”. There are 30 species of lumpsucker, ranging from the half-inch-long Lethotremus awae to the foot-long common lumpsucker (Cyclopterus lumpus). Lumpsuckers are benthic animals, meaning they live on the sea floor, and can live at depths up to 5,600 feet.

There are a few specific qualities that make the lumpsucker unique. First, they have a suction-cup-like disk on their underside, which allows them to attach to rocks and other surfaces. The disk is actually a modified pectoral fin, and keeps the fish from being swept away by ocean currents. This is especially important because lumpsuckers are not very good swimmers (their ping-pong-shaped bodies aren’t particularly hydrodynamic).

Lumpsuckers’ suction disks also play a role in reproduction. When it’s time to breed, males will migrate to shallow waters to prep a nest. The female will then arrive, deposit her eggs and take off for the open ocean. Then the male’s watch begins: He attaches to a nearby rock and stands guard over the eggs for up to eight weeks. He then uses his fins to fan oxygen-rich water over the eggs and defends the nest against potential predators. Once the eggs hatch, the male returns to deeper waters, until called again to his parental duties.

Lumpsuckers don’t have scales, and instead have bumpy protrusions all over their bodies called tubercles. Tubercles are made of keratin, which is the same substance that makes up your hair and fingernails. These lumps serve as protection from predators and give lumpsuckers their lumpy appearance. They’re not the only species with these distinctive lumps, however: many fish, including goldfish, develop tubercles during breeding season to impress potential mates.

Due to their small size, there’s not a large international fishery for lumpsuckers. But they are an important fishery in Iceland—male lumpsuckers are considering a local delicacy. They also play a unique role in salmon aquaculture: some fish farmers use lumpsuckers to eat parasitic lice off of farmed salmon.

Lumpsuckers may be known as the “pingpong balls of the sea”, but there’s much more to these tiny, sucker-having, lice-eating fish. Plus, you can’t deny that they’re pretty stinking cute!

Want more weird fish species? Check out the frogfish, red-lipped batfish and gulper eel!