What is the name of the vegetarian shark?

The vegetarian shark is Bruce.

Bruce is a great white shark who leads a support group in Finding Nemo. The group follows the slogan “Fish are friends, not food” and tries to abstain from eating fish, presenting itself as a recovery-style meeting for sharks.

Bruce is joined by the hammerhead shark Anchor and the mako shark Chum. Although the film calls the group vegetarian in comic terms, Bruce is not biologically a vegetarian species: great white sharks are carnivorous predators. His attempted diet is a character joke and a temporary behavioral vow, not a description of real shark nutrition.

The name Bruce is also an affectionate reference to the mechanical shark used during the production of Jaws. That shark was nicknamed Bruce after Steven Spielberg's lawyer, Bruce Ramer. In Finding Nemo, Bruce's self-control collapses when he smells blood, creating one of the film's tense comic sequences.