What are the slightly odd-looking (yet enormously cute) fish that could be described as resembling swimming golf balls in the Aquarium’s Puget Sound Fish exhibit? They’re Pacific spiny lumpsuckers, Eumicrotremus orbis, and the last word in their name is derived from two interesting features.
First, the “lump” part: these fish don’t have scales. Instead, they’re covered by cone-shaped plates, called tubercles, which give them their distinctive, lumpy appearance—and also serve as excellent camouflage from predators.
As for the “sucker” part, their pelvic fin is modified to form a pelvic sucker disc, which they use to adhere to rocks, eelgrass and kelp. Pacific spiny lumpsuckers don’t have a swim bladder and are generally weak swimmers, so their sucker disks serve an important function in helping them resist the strong pull of marine currents.
Pacific spiny lumpsuckers are found in shallow bays at depths up to 500 feet, from northern Washington to the Bering Sea, along the Aleutian Island chain to Siberia and northern Japan. Their maximum recorded length is about five inches, but they usually average between one and two inches. Because they’re so entertaining to watch, they’re a favorite of recreational scuba divers—but they’re usually seen only during the winter months.
Come see and learn more about Pacific spiny lumpsuckers at the Seattle Aquarium!