“This blue lobster was caught off the coast of Portland yesterday and returned to the water to continue growing. Blue lobsters are one in 2 million,” she wrote. While lobster shells are generally red or brown, the crustacean’s blue shell is the result of a genetic mutation. It causes the lobster to produce more of a particular protein than other lobsters, giving its shell a rare blue color, the Toronto Sun reported. Blue lobsters are extremely rare, but given the number of lobsters that are caught for consumption, it is inevitable that some of them will be blue. Fishermen also believe that catching a blue lobster is a sign of good luck, the BBC reported. Lobsters caught in the North Atlantic tend to be greenish-brown in color and turn pinkish red when boiled, which is what most people who consume them see. “The American lobster is usually a greenish-brown species, so any bright blue would look very strange to fishermen there,” said Charlie Ellis, a researcher at the UK National Lobster Farm in Cornwall. “But European lobsters tend to be a duller blue color. The true type of iridescent blue is still rare here, but the difference is that, to a European fisherman, it will seem less out of the ordinary than it would to an American.”

Yellow, orange and crystal-colored lobsters are considered even rarer than bright blue ones. According to the Lobster Institute, yellow lobsters make up about one in 30 million of the total populations, while the chances of catching an albino or “glass” lobster are thought to be one in 100 million. Two fishermen in Dorset caught a glass lobster in 2011. “Whatever the odds of catching different colored lobsters, there’s no denying that the bright blue ones are truly beautiful creatures,” said Rob Bayer, executive director of the Institute of University of Maine Lobster. “They may not be the most unusual, but they are certainly the best to look at.”

Some restaurants made headlines for getting a blue lobster along with their catch and giving it a new place to live. It’s become something of a trend for restaurants to save blue lobsters. Austin Hopley, chef at “The Hare” in Rochdale, UK, made headlines for saving a bright sapphire lobster.

Hopley said she suffered a “crisis of conscience” and decided to spare his life and even called him Larry. Hopley gave the lobster to Sea Life in Manchester, where he continues to live, BBC News reported. Hopley said he hadn’t seen anything like this before. “I knew the morally right thing to do was to find him a home where everyone could appreciate him,” he said. “I found it was very weird, so I thought, ‘I can’t kill this, I don’t want to.’ We couldn’t see it and put it on the menu. We spent hours contacting places. I was worried about how much time I would spend out of the water, so I called a bunch of small aquatic stores and they were all very helpful.”