Eumicrotremus orbis

While the species has been documented and described by marine biologists for over 150 years, only very few researchers have taken up the task of studying the behaviour and lifecycle of this creature. Among the knowledge that is publicly available, the majority of it has been provided by naturalists and scuba divers.

Even then, we still know so little. There is only a period of around 2 months a year that we have a chance of catching a glimpse of this rare species, and it happens to be during the period when one might be the least interested in jumping in the ocean; in the middle of winter, in the dead of night.

This artwork is inspired by my photograph of the Pacific spiny lumpsucker below:

January 2020: A very friendly lumpsucker swims up to my camera to say hello. Photographed in Saanich, B.C.

📖 Description 📖

Among the few who have caught a glimpse of this rare creature, many of them could describe it as a friendly, hovering golf ball. Most members of this species are yes, around the size of a golf ball, however there have been some exciting reports of Pacific spiny lumpsuckers from Russia reaching up to 18 centimeters in length [1]!

This creature might look helpless, swimming around aimlessly in the night, but in fact it has several adaptations that help it to evade predators. Two of these adaptations are of course, featured in its name:

Their skin is covered in short, knobby spines called tubercles which presumably make this little fish difficult for predators to swallow.
On their bellies, they have a suction cup that they use to grip onto eelgrass, kelp, rocks, and dock pilings far above the sea floor where crabs and other predators may be lurking. This suction cup is created from a modified pair of pelvic fins, and is strikingly similar to the suction cup of clingfishes and snailfishes.

December 2017: A large, female lumpsucker rests on an eelgrass blade several feet above the seafloor. Photographed in Sidney, B.C.

🌎 Distribution 🌎

The Pacific spiny lumpsucker is a small fish that is very well traveled for its size! This species can be found in just about any region of the North Pacific Ocean, including Puget Sound, British Columbia, the Gulf of Alaska, Eastern Russia, & Northern Japan [1].

Much of what we know about Pacific spiny lumpsuckers comes from recreational divers & naturalists of British Columbia, which is close to the southern most point of their documented range. It is quite possible that their migratory habits and spawning season change throughout the regions they have been encountered.

🏝 Habitat 🏝

While most often seen in the intertidal and shallow subtidal zones, The Pacific spiny lumpsucker has been documented as far deep as 575 metres [1]! You may be surprised to hear that a round, slow-swimming fish can adapt to such a wide range of depths, however it is hypothesized by some that the movement between shallow and deep habitat is an important part of this species’ lifecycle.

When encountered in shallow waters, Pacific spiny lumpsuckers are most often seen in eelgrass beds, kelp beds, and the rocky intertidal [2]. As mentioned previously, the only period you can even have a chance of seeing one of these little fish is during the winter at night. While they may be around during the daytime, lumpsuckers are attracted to the light from flashlights and dive lights.

November 2019: A Coonstripe shrimp photobombs my picture of a lumpsucker fluttering around in an eelgrass bed. Photographed at an undisclosed location on Vancouver Island.

🦐 Diet 🦐

For a tiny fish with a tiny mouth, their diet is restricted to very small creatures. As seen in the photograph below however, some lumpsuckers aren’t afraid to bite off more than they can chew!

Normally, a lumpsucker feeds primarily on small crustaceans such as amphipods and shrimps. Several divers have reported that particularly friendly lumpsuckers will actually use the lights from scuba divers to hunt for prey [2].

During one late evening, I helped a lumpsucker hunt in an eelgrass bed for over 30 minutes. Anecdotally, it would seem that these little creatures have quite the appetite!

November 2019: A male lumpsucker who had gotten a little ambitious during a hunt. This lumpsucker tried to eat the Eelgrass isopod that is now crawling over its face. Prior to this, the lumpsucker was using the light of my dive light to hunt for small invertebrates. The lumpsucker and the isopod parted ways soon afterwards. Photographed in an undisclosed location.

🐡 Life Cycle 🐡

Pacific spiny lumpsuckers are a species with a characteristic called sexual dimorphism, meaning that males and females have different colours and forms. Female lumpsuckers are green to yellow in colour and have a greater number of small tubercles on their body. Males are generally a brown or red in colour and have fewer, larger tubercles [3].

It is currently hypothesized that Pacific spiny lumpsuckers spawn in the early spring. Large numbers of freshly hatched lumpsuckers were observed in January & February in one study [3]. Some divers have also reported seeing male lumpsuckers guarding clutches of eggs inside of Giant acorn barnacle shells and rock crevices.

Soon after reproducing, it would seem that the lumpsuckers that have so briefly visited us for the winter return to the deep, as sightings of these adorable little fish taper off in the beginning of March.

February 2020: An extremely rare sighting of a blue lumpsucker on Vancouver Island. It is not known whether this specimen was male or female. Photographed in an undisclosed location.

📚 References 📚

[1] Froese, R. (n.d.). Eumicrotremus orbis (Günther, 1861). Fishbase. Retrieved January 29, 2022, from https://www.fishbase.se/summary/4184

[2] Pacific Spiny Lumpsucker. (n.d.). Aquarium of the Pacific. https://www.aquariumofpacific.org/onlinelearningcenter/species/pacific_spiny_lumpsucker

[3] Arita, G.S. (1969). Sexual Dimorphism in the Cyclopterid Fish Eumicrotremus orbis.. Journal of the Fisheries Board of Canada, 26(2). https://doi.org/10.1139/f69-312