Understanding Dory: 5 Facts About the Pacific Blue Tang

If seeing Finding Dory is part of your weekend plans, you’re not alone: Box office analysts are predicting that the new Pixar movie will likely open between $115 and $120 million. While you’re sitting around waiting for the movie start, here’s a little bit of knowledge you can drop about Dory’s species, the Pacific Blue Tang.

1. IT HAS A LOT OF ALIASES.

Though the fish's scientific name is paracanthurus hepatus, it's also known as Pacific blue tang, royal blue tang, hippo tang, regal tang and palette surgeonfish, among other things.

2. THEY HELP KEEP CORAL REEFS HEALTHY.

Blue tangs eat nothing but algae, and they’re instrumental in keeping the algae levels on coral down to a manageable level. Without the blue tang there to eat their fill, algae could overgrow and suffocate the reefs.

3. DON’T EAT DORY.

The Paracanthurus hepatus has poisonous flesh. Eating it may cause ciguatera, a foodborne illness passed on by certain reef fish that have toxins in its flesh. If you happened to accidentally ingest one, it probably wouldn’t kill you—but you’d likely come down with a bad case of diarrhea.

4. IT'S NOT ALWAYS BLUE.

Despite its name, the blue tang is not always azure. It can change color at night because of the way light is reflected from the pigments in its skin, becoming “whitish with a shade of violet.” Researchers believe its nervous system is less active at night, which may also affect its coloring. And juvenile blue tangs are bright yellow, which darkens as they mature.

5. IT CAN CUT YOU.

She may seem sweet in the movie, but the real-life Dory can (and will) cut you. The blue tang has a sharp spine that can stand erect as a means of self-defense. Because of this sharp, scalpel-looking spine, the blue tang is part of a family of fish known as “surgeonfish.”