Just how rare is a rare-colored lobster? Scientists say answer could be under the shell

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BEDFORD, Maine (AP) — Orange, blue, cotton candy, two-tone and… cotton candy?

These are all the colors of crayfish that have been showing up in fishermen’s traps, supermarket seafood tanks and scientists’ labs over the past year. The bizarrely colored crustaceans have been making headlines about their rarity, with some describing the rare blue creatures as “cotton candy-colored” and their numbers often estimated at around 1 in 100 million.

The recent appearance of strangely colored crayfish in Maine, New York, Colorado and other states has scientists wondering just how strange these color-changing arthropods really are. As is often the case in science, it’s complicated.

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Crayfish color can vary due to genetic and dietary differences, and estimates of how rare certain colors are should be treated with caution, said Andrew Good, chief managing scientist of the American Crayfish Endemism Index at the University of Maine. There is also no definitive source of crawfish color abnormalities, the scientists said.

“Anecdotally, there’s no difference in taste either,” Jude said.

In the wild, crayfish are mottled brown, turning reddish-orange after they’re boiled for eating. Judd said crayfish may have color abnormalities due to mutations in genes that affect proteins that bind to pigments in their shells.

The best estimates of lobster color abnormalities are based on data from fisheries sources, said Markus Friedrich, a professor of marine science at the University of New England in Maine. But “nobody really tracks it,” he said.

Friedrich and other scientists say commonly cited estimates like 1 in 1 million for blue lobsters and 1 in 30 million for orange lobsters shouldn’t be treated as fixed numbers. But he and his students are working to change that.

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Friedrich is developing non-invasive methods to extract genetic samples from crayfish in an effort to better understand the molecular basis of their rare shell color. Friedrich maintains a collection of oddly colored crayfish in the university’s labs and has been documenting the progress of the university’s orange crayfish, named Peaches.

The peach trees have produced thousands of babies this year, which is normal for lobsters. About half of them were orange, which is not the case, Friedrich said. A small majority of the surviving lobster babies were regular-colored, Friedrich added.

Studying the DNA of the abnormally colored lobster will give scientists a better understanding of the basic genes that make it up, Friedrich said.

“Lobsters are a special animal here in Maine, and I find them beautiful. Especially when you see these rare species, they look amazing. And then the scientist in me just says, ‘I want to know how this works. What is the mechanism?’” Friedrich said.

He eats crayfish but “not any of those colorful kinds,” he says.

One of Friedrich’s crayfish, a tamarind crayfish, is the same color on one side and orange on the other. Friedrich said this is because two crayfish eggs fused and grew as one animal. He said this is thought to be rare, occurring in less than 1 in 50 million.

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There has been a rare lobster in the news lately, with an orange lobster turning up at a Stop & Shop store on Long Island, New York, last month, and another lobster turning up in a shipment delivered to a Red Lobster store in Colorado in July.

The odd-looking lobsters are likely to continue to come ashore because of the size of the U.S. lobster fishery, said Richard Whaley, a now-retired veteran lobster researcher at the University of Maine. American fishermen have brought more than 90 million pounds (40,820 metric tons) of lobsters to docks each year since 2009, after only reaching that size twice before, according to federal records dating back to 1950.

“In an annual catch of hundreds of millions of lobsters, it should come as no surprise that we see a few exotic species each year, even if it’s 1 in a million or 1 in 30 million,” Wally said.

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