Today I right a great wrong. For how can it be I did not have a blog featuring the Pacific Spiny Lumpsucker? This is one of the most cryptic and astoundingly adapted fish in the north Pacific Ocean.
Yesterday, I chanced upon the individual in the photo below and he is what finally catalyzed this blog. Just look at him! He is only about 2 cm long. I noticed him because he was swimming / hovering around like a minuscule zeppelin. Then he alighted on a rock, securing with the pelvic disc this species relies upon.
To be a little, round fish like this, nature had to do something to make sure you don’t roll over. You need to be able to secure, not only to rock, but to seaweeds and Eelgrass. The “solution” is that Pacific Spiny Lumpsuckers are among the fish species in which the pelvic fins have evolved into a sucker on their bellies.
This species has very small pectoral fins (even relative to body size) and does not have a swim bladder to help with buoyancy. All the more need to have the disc to be able to hold on between short hovering swims.
Pacific Spiny Lumpsuckers don’t have scales but rather have lumpy, bony plates known as “tubercles”. Maybe these are what the “lump” in their common name refers to.
There have been many creative attempts to describe the overall appearance of Pacific Spiny Lumpsuckers from simply “cute” to “pingpong ball with fins”, to “swimming strawberries”, “underwater bumble bees”, and . . . “a fish that has quietly come to terms with looking idiotic”. Thanks Dr. Milton Love for that last descriptor. You can imagine the many jokes and allusions made about their name which “sounds like a Shakespearean insult” (comment made by Angela Flute on YouTube).
The species name Eumicrotremus orbis references their rotundity and size. Maximum known length is 12.7 cm but they are more often much smaller, around 2.5 cm.
I believe the Pacific Spiny Lumpsucker we saw yesterday was a male because mature males are reported to be dull orange to reddish brown. Mature females are pale green and have more and larger tubercles.
The one in Paul Wright’s video below is most definitely a male. See the egg-guarding? Male Pacific Spiny Lumpsuckers guard the eggs after fertilizing them, oxygenating them by wafting water over them and protecting them from predators. It’s reported that males die after the eggs hatch and that the females die after egg laying (average of 202 eggs, size of each egg is ~2.2 mm). Outside of when they are breeding, this is a solitary species. Appear to have a life expectancy of around 1 year in aquariums (Casey Cook, pers. com).
It is normal that Pacific Spiny Lumpsucker’s mouths are almost always open and that they appear to be panting (as you see in the video).
Further species information:
Range: Northern Washington to the Bering Sea, along the Aleutian Islands to Siberia and northern Japan. Intertidal to 575 m. Source: Lamb and Edgell, 2010.
Diet: “Small crustaceans such as gammarid andy hyperiid amphipods, along with caprellid amphipods, isopods, and cumaceans” [hooded shrimp species]. Source: Love, 2011.
Arita, G. S. (December 01, 1969). Sexual Dimorphism in the Cyclopterid Fish Eumicrotremus orbis. Journal of the Fisheries Research Board of Canada, 26, 12, 3262-3265.
Aquarium of the Pacific – Pacific Spiny Lumpsucker
Cook, Casey, personal communication November 7, 2021
FishBase – Eumicrotremus orbis
Lamb, A., & Edgell, P. (2010). Coastal fishes of the Pacific Northwest. Madeira Park, B.C: Harbour Pub.
Love, M. S. (2011). Certainly more than you want to know about the fishes of the Pacific Coast: A postmodern experience. Santa Barbara, Calif: Really Big Press.
New York Times, Feb. 25, 2022, The Pacific Spiny Lumpsucker Is Armed to the Teeth – The diminutive predator is a terrible swimmer but thrives in the intertidal zone thanks to odd evolutionary adaptation.
University of Washington – College of the Environment Feb. 8, 2022, , This tiny coastal fish wears a toothy coat of armor