Dogfish got their name from fishermen who watched them hunt in large, coordinated groups and thought they looked like packs of dogs chasing prey. The comparison stuck, and “dogfish” has been the common name for these small sharks for centuries.
The Pack Hunting Connection
The name comes down to one striking behavior: dogfish travel and feed in enormous schools, sometimes numbering in the hundreds or thousands. When fishermen saw these swarms pursuing schools of smaller fish, the image that came to mind was a pack of dogs running down prey. The word “pack” is the key link. Dogs hunt cooperatively in groups, and dogfish appear to do the same thing underwater, sweeping through an area and aggressively feeding on whatever they find.
These schools aren’t random. Spiny dogfish, the most well-known species, sort themselves by size and sex, forming groups of similarly sized individuals. This organized schooling behavior, combined with their relentless, opportunistic feeding style, made the canine comparison feel natural to the people who encountered them most often: commercial fishermen hauling nets and setting lines.
More Than Just Schooling
The pack behavior is the primary reason for the name, but dogfish share a few other traits that reinforce the comparison. They’re aggressive, opportunistic feeders that eat whatever prey is available, much like scavenging dogs. NOAA describes their feeding nature as aggressive enough that they frequently bite baited hooks meant for other species, making them one of the most common accidental catches in recreational fishing. Fishermen who dealt with dogfish constantly snagging their gear likely had some choice words for them, and “dog” fit the bill.
Dogfish also have a strong sense of smell that guides them toward food. Early research from the U.S. Fish Commission documented sharks following scent trails through the water from as far as a quarter mile away, tracking odor currents the way a hound follows a trail on land. While this comparison wasn’t the origin of the name, it added to the overall impression of a dog-like animal.
Which Sharks Are Called Dogfish?
The name “dogfish” doesn’t refer to just one species. It’s a broad common name applied to several families of small sharks. The most familiar is the spiny dogfish, found in temperate oceans worldwide and formally described by Carl Linnaeus in 1758. But the label extends to smooth dogfish, which have flat, blunt grinding teeth designed for crushing crabs and shellfish rather than the sharp cutting teeth most people associate with sharks. There’s also the lesser spotted catshark, sometimes called a dogfish in European waters.
The U.S. Fish and Wildlife Service officially recognizes “dogfish sharks” as the common name for the entire family Squalidae, which contains around 29 species across two genera. So while the spiny dogfish is the poster child, the name casts a wide net. What these species share is their small size relative to other sharks, their tendency to school, and their abundance in coastal waters where fishermen regularly encountered them.
The Latin Name Tells a Different Story
Interestingly, the scientific names for dogfish don’t reference dogs at all. The genus name Squalus comes from a Latin word meaning “shark,” with possible roots in a word meaning “pale” or “weak.” The smooth dogfish genus, Mustelus, translates to “weasel-like.” One species name does nod to the canine connection: the lesser spotted catshark carries the Latin species name “canicula,” with “canis” meaning dog. But for the most part, the scientists who classified these animals chose different reference points than the fishermen who named them.
Dogfish by Any Other Name
If you’ve eaten fish and chips in Britain, you may have had dogfish without knowing it. The name isn’t exactly appetizing, so fishmongers and chip shops have long sold it under more appealing labels: rock salmon, rock eel, flake, or huss. These names can refer to spiny dogfish, smooth-hound sharks, or rough-hounds, all species that fall under the dogfish umbrella. The rebranding worked well enough that many customers had no idea they were eating shark.
That commercial popularity came with consequences. Spiny dogfish are now classified as Vulnerable on the IUCN Red List, and the population in the northeast Atlantic is considered Critically Endangered. Their biology makes them especially slow to recover: they grow slowly, mature late, and produce small litters. The same schooling behavior that earned them their name also made them easy to catch in large numbers, since entire same-sex, same-size groups could be swept up in a single trawl.