Are There Any Fish That Are as Bad at Swimming as Humans Are?

In this edition of Ask a Marine Biologist, Dr. David Shiffman discusses the swimming abilities of fish.

Question: Are there any fish that are as bad at swimming as humans are? —Vicky S, Washington, DC

Answer: While I suppose it depends on how you define “bad at swimming,” the short answer is yes, there are tons of fish species that are not particularly well adapted for fast, efficient, long-distance movement through the water. Remember that goofy Shark Week special a few years ago where Michael Phelps “raced” a shark and got his caudal fin kicked? There are lots of fishes that he could have beaten in a race—heck, there are lots of fishes that even I could beat in a swimming race. You only ever seem to hear about fish superathletes, but the sea has plenty of couch potatoes too! Fish don’t need to be capable of amazing feats of swimming to be ecologically important, fascinating or beloved!

Sure, it’s impressive that shortfin mako sharks can swim up to 60 miles per hour (or about 26 meters per second). But did you know that the Greenland shark swims at a glacial 0.34 meters per second, making it the slowest-swimming large fish ever recorded. If an animal that swims that slowly can somehow catch and eat seals (as well as polar bears and reindeer), there’s probably some sort of inspirational message out there for those of us unlikely to make the Olympic swimming team.

Sure, transoceanic migrations like those made by European eels are pretty cool. But consider the slimy sculpin, a cool fish in desperate need of rebranding (I proposed renaming it to “sentinel sculpin” to a team of scientists who study these animals, which sounds way better). In a recent study, scientists put telemetry tags on slimy sculpin and found that half of them moved less than 10 meters in a whole year. This extremely limited “home range” actually makes the slimy sculpin an incredibly useful study species, because problems in their environment will be very easy to study—it’s not like they swim through a lot of different habitats that would complicate such an analysis. And all those tiny fish that live in cracks and crevices of coral reefs, collectively known as “cryptobenthics,” play a critical role in the food-web dynamics of a reef —it’s not only the long-distance swimmers that matter!

There’s no doubt that the torpedo-like shape of a tuna is a marvel of evolution, allowing for incredibly fast and efficient movement through the water. But everyone loves a good Mola mola or lumpsucker despite their not particularly hydrodynamic shapes, which have inspired approximately zero naval engineering innovations.

Fish are a diverse group of animals, with tens of thousands of species of all shapes, sizes, habitats and behaviors. Some of those fishes are superathletes, capable of amazingly fast or efficient swimming across vast distances. Others aren’t even a match for those of us without fins. A lot of public science outreach has focused on the incredible feats of swimming that some fish species are known to accomplish, but the many fish species that can’t do this are also worthy of fame, study and protection.

Ask a Marine Biologist is a biweekly column where Dr. David Shiffman answers your questions about the underwater world. Topics are chosen from reader-submitted queries as well as data from common internet searches. If you have a question you’d like answered in a future Ask a Marine Biologist column, or if you have a question about the answer given in this column, email Shiffman at WhySharksMatter@gmail.com with subject line “Ask a marine biologist.”

Dr. David Shiffman is a marine conservation biologist specializing in the ecology and conservation of sharks. An award-winning public science educator, David has spoken to thousands of people around the world about marine biology and conservation and has bylines with the Washington Post, Scientific American, New Scientist, Gizmodo and more. Follow him on Twitter, Facebook and Instagram, where he’s always happy to answer any questions about sharks.