This article is more than 2 years old.

May 11, 2016 This article is more than 2 years old.

When ”Finding Nemo,” the Pixar Animation Studios movie about a young clownfish, became a box office hit in 2003, sales of orange-and-white striped clownfish multiplied at pet stores and aquariums around the world. People wanted their own Nemos.

Now “Finding Dory,” which tells the story of a blue tang fish—voiced by Ellen DeGeneres—who befriended Nemo’s father in the 2003 film, is about to hit theaters. Soon lots of people will want to buy blue tangs like Dory.

Unlike clownfish, which are relatively easy to breed in captivity, blue tangs don’t survive well in aquarium tanks. Breeding Dory fish will not be easy. According to the marine science magazine Hakai, ”As Dory graduates from sidekick to leading lady, the lack of a captive-bred option will drive collectors to source more blue tangs from the wild—a harvest that’s often unregulated and destructive.”

Marine biologists estimate that more than 20 million live sea creatures are taken from the wild to become pets in private and public aquariums. The network of harvesters, distributors, and sellers is complex, and on average not especially conservation-minded.

Blue tangs live among fragile coral reefs in the Indo-Pacific, which are easily damaged by fish collection techniques.

Wikimedia Commons The blue tang in real life. These fish, which feed on zooplankton and coral algae, can grow to 12 inches in length.

To save the wild fish and their home reefs, scientists are trying to make captive breeding of blue tangs viable. As Hakai reports, a collective of aquariums and conservation organizations are funding this research. The would-be Dory breeders haven’t had much luck yet—and they’re running out of time: “Finding Dory” starts showing on June 17.