The oyster crab is a very small crab that ranges in color from pale orange to a shade of yellow that is so light that it is nearly white. Zaops ostreus is the Latin name for this species, which is from the Pinnotheridae family. The crab has translucent body parts. These crabs get their name from the place where they live — inside the gills of a clam or oyster.
As this species lives within the body of another kind of shellfish, it must be very small. An adult specimen is usually no larger than 0.5 inch (1.27 centimeters) across. This tiny crustacean has very few natural defenses, and in fact, its key line of protection is the shell of the oyster or clam in which it resides. Its food source also comes from the oyster or clam that protects it — it does not eat its host but ingests some of the food that the larger shellfish collects for its own nutrition.
Oyster crabs are most commonly found in shellfish that live in the Atlantic Ocean, particularly in northern waters. The incredibly small crab is consumed as a delicacy and can be added to stews and even omelets. Sometimes, it's referred to as a "baby" soft shell crab. As it is not easy to fish for and because of its incredibly small size, it is an expensive ingredient and is not always easy to find.
Some plants that process clams and oysters do not even bother to harvest any oyster crabs that the come across during the shucking process. Often, they are simply found as a sort of culinary surprise when they are opened by chefs. For this to happen, the clams or oysters have to be shipped live to the restaurant kitchen. There are some companies that also ship life shellfish to individual home cooks, and in this case, there is also the opportunity for a surprise treat.
Because this kind of crab is so rare, there are few recipes that call for them. One of the best ways to bring out the flavor is to simply saute them in butter. The flavor is sometimes compared to that of shrimp.