Last week the waters of Chesapeake Bay yielded a blue crab with a unique feature: two oysters growing on either side of her head.
“It’s very rare to see this,” Tom Zolper, a spokesman for the Chesapeake Bay Foundation, told The Washington Post, “where two oysters have set on a crab in this sort of pattern with one on each side of the crab, almost over her eyes.”
According Zolper, the crab’s vision is likely impaired, as the oysters are growing next to her eyes and might allow her to only look upward and not straight ahead. He guessed that the crab has probably tried removing the oysters from their nesting ground.
“Whatever she’s tried, she’s tried,” he said. “They’re there and they’re attached.”
The unique situation likely occurred because oyster larvae need a hard surface to attach to and grow. Typically, old oyster shells and reefs do the trick, but Zolper suggested that pollution and overharvesting over the years have reduced the availability of these traditional surfaces to the extent that oysters occasionally attach themselves to crabs.