'I never thought I’d see another': 2 white Dungeness crab on display at Oregon aquarium
“I’ve seen an all-white Dungeness once before, in 2013, but I never thought I’d see another,” said Roman Smolcic from the F/V Norska, one of the boats that found the white crabs.
Smolcic and his crewmates found the ghostly looking crab while pulling pots near Cascade Head in January.
“The other guys on the crew had never seen a crab like that," Smolcic said. "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.”
Such pale crabs are quite rare, said Scott Groth, a shellfish biologist with the Oregon Department of Fish and Wildlife.
An estimated 1 out of every 1 million Dungeness crab are white.
“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.”
So why are the crab white?
"Dungeness crabs are opportunistic animals, grazing on detritus as well as feeding on many species of fishes and invertebrates," Aquarium staff explained. "The usually brownish-purple coloration of these crabs likely helps to camouflage them in the murky depths. How an all-white individual managed to escape detection by predators for long enough to mature is a mystery."
Because humans aren't the only creatures interested in eating crab.
“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.”
Upon reaching adulthood, a full-grown Dungeness is tougher prey for predators, Vance said.
DID YOU KNOW ... More about Dungeness crab, from the Oregon Coast Aquarium
DO THEY CHANGE OTHER COLORS? "While an all-white crab might seem strange, it turns out that such aberrations are known to occur on something of a spectrum. ODFW reports that crabs are brought to their attention with partial lack of pigment, hyperpigmentation, or pigmentation in odd patches or patterns."
A SPECIAL SPECIES FOR OREGON: "Dungeness crab is an iconic species of the Pacific Northwest, prized for its delicious and commercially valuable meat. At the Aquarium, we regularly feature Dungeness crabs in our exhibits, and even devote an entire day event to them. It’s an animal that can be found right outside our doors, in the brackish waters of Yaquina Bay. Dungeness crabs enter estuaries to feed and seek shelter, and their larvae find refuge in the expansive eelgrass beds."
LIFE CYCLE: "Dungeness crabs typically live to about 10 years, reaching adult size at 4-5 years old. The white crabs in our Sandy Shores Gallery measure more than eight inches across the carapace—they’re definitely adults, but their age is unknown."