Pacific spiny lumpsucker
The Pacific spiny lumpsucker (Eumicrotremus orbis) is a species of bony fish in the family Cyclopteridae.
Pacific spiny lumpsucker | |
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Scientific classification ![]() | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Scorpaeniformes |
Family: | Cyclopteridae |
Genus: | Eumicrotremus |
Species: | E. orbis |
Binomial name | |
Eumicrotremus orbis Günther, 1861 | |
Synonyms[1] | |
Description

Pacific spiny lumpsuckers are a globular-shaped fish that typically measures 1 to 3 inches (2.5 to 7.6 cm) in length, though the most common size is 1 inch (2.5 cm).[2][1][3][4] It has a maximum known length of around 5 to 7 inches (13 to 18 cm).[4]
They have a wide mouth with large lips, and protruding eyes.[4] The fish also has a squared dorsal fin, rounded caudal fin, and thin, transparent pectoral fins.[4]
The lumpsucker's pelvic fins have evolved into a large, fringed suction cup, allowing it to attach to surfaces.[4][2][5][3] This sucker also compensates the fish for its lack of gas bladder.[4] Because of their large, rounded shape with small fins, Pacific spiny lumpsuckers are ineffective swimmers and are most commonly found attached to solid objects.[2][3][4]
They do not have scales.[4] Instead, the body of the fish is covered in cone-shaped plates, called tubercles.[2][3][5][4] Females have more tubercles than males.[4]
The Pacific spiny lumpsucker is seen in many colors, including brown and green, often with yellow or orange highlights.[4] Females are dull green in color, while males are dull orange to reddish brown.[6][3]
Behavior
Pacific spiny lumpsuckers are often found alone in nature.[4] When disturbed, they swim about aimlessly, hindered by their inefficient swimming.[4] Instead, the fish relies on effective camouflage to avoid detection from predators.[4]
They are considered harmless to humans.[1]/>[6] In fact, they are known to eat out of the hands of divers.[4]
Distribution and habitat
Pacific spiny lumpsuckers are found from northern Washington state, especially Puget Sound, to the Aleutian Islands of Alaska.[2][3] They can also be found in the Bering Sea, the Chukchi Sea and around northern Japan.[1]>[3][4]
This species inhabits a wide variety of habitats, including eelgrass beds, rocky reefs, kelp patches, and other algae growth.[2][5][4] They are also found around shallow bays and docks.[2][3] The fish lives in near-shore waters to a depth of 480 to 500 feet (150 to 150 m).[2][5][4]
Ecology

Diet
Pacific spiny lumpsuckers feed on slow crustaceans, polychaete worms, and mollusks on the sandy or muddy sea floor.[4]
Reproduction
The species is known to spawn in shallow, warmer waters between the months of July and October.[4] The females lay large, spherical, orange-colored eggs on rocks, in sheltered holes.[4] Females typically lay around 200 eggs at a time in the nest and the male fertilizes them.[6][4] After the eggs are laid, the male attaches himself to a nearby surface where he cares for the eggs by defending them from predators and circulating water over them with his fin.[4]
Predators
Pacific cod, sablefish, marine sculpins, and lancefish are known predators of pacific spiny lumpsuckers.[4] Crabs, sea stars and small fishes prey on lumpfish eggs.[4]
Climate change
While the Pacific spiny lumpsucker has not yet been evaluated by the IUCN Red List, climate change may pose a threat to the species.[4] The fish relies on shallow waters for breeding and eelgrass for habitat.[4] Rising sea levels and warmer water temperatures threaten these habitats, and the species' survival.[4]
References
- Froese, Rainer; Pauly, Daniel (eds.) (2023). "Eumicrotremus orbis" in FishBase. February 2023 version.
- Paul., Humann (1996). Coastal fish identification : California to Alaska. Hall, Howard, 1949-, McDaniel, N. G. (Neil Glenn), 1949-, DeLoach, Ned. Jacksonville, FL: New World Publications. ISBN 1878348124. OCLC 35233771.
- "About Pacific Spiny Lumpsucker". Oregon Coast Aquarium. Retrieved 2021-07-05.
- "Pacific Spiny Lumpsucker". Aquarium of the Pacific. Retrieved 2021-07-06.
- N., Eschmeyer, William (1983). A field guide to Pacific Coast fishes of North America : from the Gulf of Alaska to Baja, California. Herald, Earl Stannard. Boston: Houghton Mifflin. ISBN 0395331889. OCLC 8668331.
- Arita, George S. (1969). "Sexual Dimorphism in the Cyclopterid Fish Eumicrotremus orbis". Journal of the Fisheries Research Board of Canada. 26 (12): 3262–3265. doi:10.1139/f69-312. ISSN 0015-296X.