Pacific Blue Tang (Paracanthurus hepatus) Profile

"Dory" In The Ocean and In Your Marine Aquarium

Pacific blue tang
School of pacific blue tang fish. Jeff Hunter / Getty Images

The Pacific Blue Tang became famous with the first viewing of the movie "Finding Nemo". Nemo's traveling mate was "Dory", a Hippo or Pacific Blue Tang. Ironically, in the wild (and even in an aquarium), the "Dory fish" acts very much like the movie character, seeming to have a short memory span and flitting all over the place. The producers did an excellent job of researching the characteristics of this fish when writing the movie.

In a saltwater aquarium the Pacific Blue Tang (Paracanthurus hepatus) is very active, therefore requiring a large tank, preferably at least 100 gallons or more. In a saltwater aquarium, the Blue Tang is an easy fish to get along with. It doesn't really bother any other fish or invertebrates but may have a problem with other fish of the same species. If you are going to have more than one Hippo Tang in a tank, introduce them at the same time and be sure to have plenty of hiding places for them to retire to when they are challenged by other Blue Tangs. The Pacific Blue Tang will find the oddest hiding places. It will, quite often, stick its head into a crack in the live rock with its body sticking out and believe that it is entirely hidden. It will also lay flat on the substrate, thinking it is hidden, and allow itself to be physically picked up without a struggle.

Scientific Name:

Paracanthurus hepatus (Linnaeus, 1766).

Other Common Names:

Hippo Tang, Blue Regal Tang, and Palette Surgeonfish. Also recognized and known as "Dory", the fish in the Disney movie Finding Nemo.


Native to reefs across the Indo-Pacific.

Average Size:

12.2 inches (31 cm).

Characteristics and Compatibility:

Not overly aggressive towards other tank mates, but may become boisterous in the community.

Juveniles can be kept together in groups, but adults will fight unless ample shelter and swimming room is provided. Prone to contracting ich, and susceptible to head and lateral line erosion (HLLE), like most Surgeonfishes, are.

Diet and Feeding:

Unlike most tangs or surgeonfishes that require a steady diet of algae, the Pacific Blue Tang should also be fed meaty fares to satisfy its zooplankton dietary needs. Finely chopped fresh or frozen shrimp, mysid shrimp, brine shrimp, and preparations for herbivores are suitable foods, as well as nori (dried seaweed) is accepted. To help with healing of HLLE problems, foods can be soaked in a liquid vitamin supplement, such as Selcon, and Kent Marine Zoecon.


A fish that is very active, it should be provided with plenty of room to move around, and an ample supply of live rock to graze on at its leisure is beneficial.

Suggested Minimum Tank Size:

100 gallons (379 L).

Reef Tank Suitability: