A pair of rare white Dungeness crabs were spared from the dinner table and are now on display at the Oregon Coast Aquarium.
The crabs were pulled from the waters off the central Oregon coast by crab boats earlier this year and, in each case, they clearly stood out from the other crabs.
Roman Smolicic, a fisherman working on the F/V Norska, said he had seen an all-white crab once before in 2013, but for the rest of the crew, it was a first.
"We took a vote on it and decided that we should donate the crab to the aquarium, so that other people could have a chance to see this unusual animal alive," he said.
Scott Groth, a shellfish biologist with the Oregon Department of Fish and Wildlife, said the occurrence of pale crabs are thought to be as low as one in a million.
Having two at the same time in the same place is obviously even more improbable.
"In Oregon we harvest between 15-20 million pounds of Dungeness a year," said Groth. "Each adult crab averages about two pounds. That's something like 8 million crabs annually. We receive reports of these anomalous individuals maybe two or three times a year, so the odds of finding them are quite low."
The usually brownish-purple coloration of Dungeness crabs likely helps to camouflage them in the murky depths. How all-white crabs managed to escape detection by predators for long enough to mature is a mystery to biologists.
"Juvenile Dungeness crabs are prey items to a wide variety of animals," said Mitch Vance, shellfish project leader at ODFW. "If an all-white juvenile crab is crawling around on the bottom, almost glowing against the dark substrate, it's more likely to be picked off by predators."
Dungeness crabs typically live to about 10 years, reaching adult size at 4-5 years old. The white crabs at the Oregon Coast Aquarium are more than 8 inches across the carapace, so they're definitely adults, but their age is unknown.
The Oregon Coast Aquarium is a nonprofit association in Newport.
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