Lumpfish

About the lumpfish

Appearance

These chubby-looking fish have round, stout bodies and large eyes. They're not the fastest swimmers, propelling themselves through the water with their fanlike pectoral fins and broom-shaped caudal fin. 

Lumpfish live up to their name with the assortment of lumps, bumps, and ridges on their rough skin. One of our aquarists describes lumpfish skin as "feeling like old, mold-crusted Jell-O".

Instead of scales, a lumpfish’s body is covered with spots and fleshy knobs  called tubercles. A row of larger bumps line the side of their body. The thick layer of skin covering the first dorsal fin creates an enormous ridge along their backs, making lumpfish look like they’re sporting massive, meaty mohawk! 

Suction discs

Have you ever stuck a loofah to your shower wall with a suction cup? The lumpfish sports a modified pelvic fin that allows them to attach themselves to objects. Just like your loofah’s suction cup keeps it in place, the lumpfish’s suction disc helps them hold tight to a frond of kelp or a rock when a strong current passes. 

The lumpfish belongs to a whole group of fishes that share this fascinating feature. They’re part of the family Cyclopteridae, from the Greek words for "circle" and "fin.”

Color

A young lumpfish might match the color of their surroundings, then develop pale grey to light blue skin as an adult. A breeding male turns orange-red in color, whereas a female shifts to blue-green.

Size

Some lumpfish species (like the Pacific spiny lumpsucker) are small and round and look like tiny, colorful chewing-gum bubbles. In contrast, Cyclopterus lumpus is bulkier, heavier, and lumpier. Males grow to 20 inches (50 cm) and females grow even bigger—up to 24 inches (61 cm)! The largest lumpfish can weigh up to 21lb (9.5 kg) but are typically much smaller.

Diet

A lumpfish isn’t a picky eater. They nosh on floating shrimp and jellies, or snap up small fish like herring and sand lance. 

Habitat

In the first year of its life, a young lumpfish clings to seaweed in shallow nearshore waters. As adults, they move further from shore, spending more time  in colder waters on the rocky seafloor.

The lumpfish lives throughout the North Atlantic. With a range spanning international borders, they’ve accumulated names in a variety of languages, including “henfish” and “lumpsucker” in English and “big sea chicken” (grosse poule de mer) in French. 

Migration

A lumpfish spends the winters alone, feeding in cold waters. In the summer they migrate to warm, shallow waters to breed.

How do lumpfish reproduce?

During the breeding season, lumpfish leave the deep, cold waters of the open ocean and swim towards shore to spawn. 

The male arrives first to make a nest in a bedrock crevice or depression in the seafloor. Next the female arrives, quickly deposits a spongy egg mass with 140,000 eggs or more into the nest, then swims off. She makes her way towards deeper waters and leaves most of the work to the male to raise the offspring.  

Once fertilized, a lumpfish nest requires defense. The male takes on guard duty by suctioning himself next to the nest, fanning it with his fins, and chasing away any potential predators. He fasts this entire time and waits to eat until after the eggs hatch.

What eats lumpfish?

A variety of animals ranging from marine mammals to fish prey on lumpfish, with predators including seals, skates, sperm whales, sharks, and orcas.

Suction discs

Have you ever stuck a loofah to your shower wall with its suction cup? The lumpfish sports a modified pelvic fin that acts as a suction disc and allows it to attach itself to objects. Just like your loofah’s suction cup keeps it in place, the lumpfish’s suction disc holds it tight to a piece of kelp or rock when a strong current passes.

The lumpfish belongs to a whole group of fishes that share this fascinating feature—it’s part of the family Cyclopteridae, which comes from Greek words for "circle" and "fin.”

Conservation

Lumpfish are designated ”Near Threatened” by the  International Union for the Conservation of Nature and Natural Resources (IUCN).

Overfishing is an ongoing threat to their survival. Male lumpfish are considered a delicacy in some cultures, while female lumpfish are sought after for their roe which is sold as affordable caviar. Other threats the lumpfish faces include habitat change and seismic exploration, in which seismic waves are sent into the earth to help search for oil and gas.

Color

Cyclopterus lumpus changes color as it ages. A young lumpfish might match the color of its surroundings, and develop pale grey to light blue skin as an adult. A breeding male will turn orange-red in color whereas a female will turn blue-green.

Cool facts

• For salmon farmers, the parasitic copepod known as sea lice are a big problem. They infest salmon, stunt their growth, and put their health at risk. Since lumpfish eat sea lice, farmers use them to protect cultured salmon as safe alternative to chemical treatments.
• These fish are right on the money! In Iceland, lumpfish earned a spot on the national currency–the 100 Króna ($0.80 USD) coin features a lumpfish.

Habitat

In the first year of its life, a young lumpfish clings to seaweed in shallow nearshore waters. As an adult, it moves further from shore, spending more time in colder waters at the stony, rocky seafloor.

The lumpfish lives throughout the North Atlantic. With a range spanning international borders, it has accumulated names in a variety of languages, including “henfish” and “lumpsucker” in English and “big sea chicken” (grosse poule de mer) in French.

Migration

A lumpfish spends the winters alone, feeding in cold waters. In the summer it migrates to warm, shallow waters to breed.

How do lumpfish reproduce?

During the breeding season, lumpfish males and females leave the deep, cold waters of the open ocean and swim towards shore to spawn.

A male will arrive first, making a nest in bedrock crevice or depression in the seafloor. Then the female arrives. She quickly deposits a spongy egg mass with 140,000 eggs or more into the nest, then swims off. She will make her way towards deeper waters and leave most of the work to the male to raise their offspring.

Once fertilized, the nest requires defense. The male takes on this duty, suctioning himself next to the nest, fanning it with his fins, and chasing away any potential predators. He fasts this entire time and waits to eat until after the eggs hatch.

Conservation

This lumpfish species has been designated ”Near Threatened” by the International Union for the Conservation of Nature and Natural Resources (IUCN).

Humans eat lumpfish—and overfishing remains a threat to their survival. Males lumpfish are considered a delicacy in some cultures, while female lumpfish are sought for their roe, which is sold as affordable caviar. Other threats the lumpfish faces include habitat change and seismic exploration, in which seismic waves are sent into the earth to help search for oil and gas.