Quiz: Test Your Knowledge of Dogfish

Pacific spiny dogfish swimming in the Underwater Dome habitat at the Seattle Aquarium.
Pacific spiny dogfish

Stand in our Underwater Dome for a few minutes, and you might catch a glimpse of the Pacific spiny dogfish living there. How much do you know about this nimble, fierce and yet understated fish? Sink your teeth into our quiz to find out.

1. What is the relationship between dogfish and sharks?

  1. Dogfish look like sharks but aren’t true sharks.
  2. Dogfish are sharks.
  3. Dogfish swim with sharks for fun.
  4. Dogfish eat sharks.

2. Where does the name “dogfish” come from?

  1. Dogfish love to chew on bones.
  2. Dogfish wag their tails like dogs.
  3. Dogfish hunt in large packs like dogs.
  4. Dogfish have fur under their scales.

3. How do dogfish stand out from other Aquarium residents?

  1. Dogfish are among the longest-living residents: They can live 80 or more years.
  2. Dogfish reproduce later: Females often don’t have pups until their mid-30s.
  3. Dogfish have exceptionally long pregnancies—nearly two years.
  4. All of the above.

4. Dogfish love to sink their sharp teeth into dinner. Which of these isn’t on the menu?

  1. Coral
  2. Herring
  3. Shrimp
  4. Clams

5. Where on their bodies do dogfish have venom—a key defense from predators? 

  1. In their teeth
  2. In two spines located on the front of their dorsal fins
  3. On their bellies
  4. In spikes on their tails

6. Dogfish are skilled long-distance swimmers. One dogfish that was tagged in Washington was later found in …

  1. Hawaiʻi
  2. California
  3. Japan
  4. Canada

7. It’s unusual for Americans to eat dogfish, but during World War II, U.S. fisheries began targeting the Atlantic spiny dogfish. Why?

  1. Dogfish were considered a good source of vitamin A before synthetic vitamin A was invented.
  2. Eating dogfish was viewed as patriotic.
  3. Chewing on dogfish skin helped maintain strong teeth.
  4. Dogfish venom was seen as healthy.

8. Why are Pacific spiny dogfish populations healthy now, even though dogfish populations worldwide are endangered?

  1. Pacific spiny dogfish are managed by National Oceanic and Atmospheric Administration fisheries and the Pacific Fishery Management Council—and fisheries management helps protect species.
  2. We don’t eat Pacific spiny dogfish, so there isn’t a commercial demand for them.
  3. Recreational fishing rules help manage Pacific spiny dogfish populations.
  4. All of the above.

Learn more about dogfish by exploring our dogfish webpage or visiting the Seattle Aquarium’s Underwater Dome.

Answer Key

1. B 
Although dogfish are much smaller than their more well-known counterparts, they're sharks just like hammerheads and great whites. What classifies a fish as a shark? A skeleton made of cartilage instead of bone, among other distinctions.

2. C
Hundreds of dogfish can join a hunt, allowing packs to tear through schools of prey. And while they have no fur, dogfish—like other sharks—have skin made of small tooth-like scales called denticles.

3. D
Because female dogfish don’t reproduce until well into their lifespans, dogfish populations can be especially vulnerable to overfishing.

4. A
Dogfish living in the Underwater Dome have been known to gnaw through a whole herring in seconds. Because dogfish live alongside other animals in the Dome, Aquarium staff ensure they eat well and regularly.

5. B
Dogfish living in the wild might use their venom on sixgill sharks and seals—two of their common predators.

6. C
The dogfish that traveled from Washington state to Japan swam an estimated 5,000 miles. That’s more than 160,000 laps in an Olympic-sized swimming pool.

7. A
Today, many of the Atlantic spiny dogfish caught by U.S. fisheries aren’t eaten here; they’re shipped to European markets for meals such as English fish and chips.

8. D
Overfishing, pollution and lack of prey are threats to dogfish populations worldwide. Explore what you can do to protect our one ocean and the animals that call it home on our take action page!

Support the Seattle Aquarium

Your support connects people to the ocean in a way not otherwise possible and inspires bold action to care for animals and protect our shared marine environment.