And similar approaches have been used to beef up carp, tilapia, catfish, and other aquatic animals, including oysters. Other researchers are experimenting with different ways of using CRISPR to boost disease resistance or create salmon that make more omega-3.

You won’t find CRISPR animals as products on supermarket shelves just yet. But some are remarkably close. In 2021, Japan approved the sale of two CRISPR-edited fish. One of them is the beefed-up red sea bream. The other is a tiger puffer fish that’s also designed to be heavier.

The researchers behind the transgenic catfish are hoping they’ll get it approved for commercial production in the US. But that could take a while. Only one gene-edited fish has so far been approved for sale in the US—and it took decades to get to that point.

That fish, AquAdvantage salmon, has a genetic modification that makes it grow bigger. As a result, it takes 25% less feed to get these salmon to the size at which they can be sold, says Sylvia Wulf, CEO and president of AquaBounty, the company that produces the fish.

The company made its first genetically engineered fish in 1992. But it didn’t enter the US market until 2021. “For a startup company founded in 1991, it took over 30 years to bring its innovative Atlantic salmon to the market, at a cost exceeding US$100 million,” says Wulf.

The approval of gene-edited pigs had a similar timeline. It was in 2001 that PPL Therapeutics (now known as Revivicor) created pigs genetically engineered to lack a sugar called alpha-gal. The company’s main goal is to use the pigs to grow organs that can be transplanted into people, whose immune systems would be likely to reject an organ with this sugar in its cells.

But in 2020, the FDA approved the animals for human consumption. These gene-edited pork products, which could be safe for people who are allergic to alpha-gal, will initially be available by mail order only, according to an FDA news release.

It’s difficult to predict how quickly CRISPR animals will progress through the US approval process. But they are on their way.