Stone crabs

Quick Take

• Stone crabs are one of the only seafood animals harvested without being killed, though whether they actually survive the process depends on a critical catch. Harvest regulations explained →
• Stone crabs have a dominant "hand," and the crushing force behind it is borderline unbelievable. Right-handedness and claw strength →
• Once a stone crab's claw is removed, regrowth is not guaranteed, and whether it occurs depends entirely on human behavior. Claw regeneration and survival →
• A female stone crab can produce an almost incomprehensible number of eggs in a single event, but the law steps in before she even gets the chance to hatch them. Egg-laying and mating details →

Over 90 percent of the marketed stone crabs come from Florida. In fact, the animals are often referred to as Florida stone crabs. But you can find this crab in offshore and coastal waters from Belize to North Carolina. They also populate the waters of the Gulf of Mexico, the Greater Antilles, the Bahamas, and the Yucatan Peninsula. The stone crab’s claws are an expensive global delicacy.

5 Incredible Stone Crab Facts

Here are five cool things you likely didn’t know about the stone crab.

• Stone crabs are generally right-handed: The right hand is often bigger than the left and stronger. The animal has powerful claws either way. The limb is capable of exerting a crushing force of 19,000 pounds per square inch.
• Females live a little longer: Female crabs will have a lifespan of at least eight years. The male stone crab tends to live for around seven years.
• The stone crab manages a huge family: Females produce an external egg mass (called a sponge) beneath their abdomen, and in a single spawning event, they can lay up to 1,000,000 eggs.
• Only claws get harvested: Claws have a short shelf life. When shopping, you have to assess them through touch and smell. If there’s even a slight odor of ammonia or the limbs are slimy and/or sticky, you don’t want to buy them.

Classification and Scientific Name

The stone crab includes two recognized species: Menippe mercenaria (Florida stone crab) and Menippe adina (Gulf stone crab). The two species do create hybrids through interbreeding, although they are usually considered one species for commercial fishing.

The stone crab is a member of the kingdom Animalia. This is a broad term for any eukaryotic, multicellular organism that consumes organic material, is able to move, reproduces through sexual contact, and breathes oxygen.

Species

In the Southeastern United States, there are two unique species of stone crabs. The Menippe mercenaria is found in Florida’s peninsula. The Menippe adina swims in the western and northern Gulf of Mexico waters.

The two species are distinguished by their genetics and coloration. There are also differentiating traits regarding reproduction, temperature tolerance, salinity, and ecology.

Here are several characteristics that separate the species.

Evolution and Origins

Florida is the primary source of an impressive 98% of stone crabs. Over the course of evolution, five distinct branches within the decapod family have independently undergone adaptations that resulted in the formation of crabs.

Under specific environmental conditions, certain traits have proven advantageous, leading multiple species to gradually develop crab-like characteristics over time.

Appearance

The animal is brownish-red with grayish spots and a tan belly. Their large pincers have black tips, and the sizes are unequal.

The stone crab’s shell, or carapace, is about four inches wide and between three and 3.5 inches long. The carapace is smooth, oval, and convex.

The crab’s body is divided into a cephalothorax and a small abdomen, with five pairs of walking legs that have distal hairs and yellow and reddish bands.

The baby crab has a white spot on the middle segment of the animal’s endopod. Juvenile stone crabs are lighter in color and gradually develop the characteristic adult coloration as they mature.

Females have larger carapaces, while males have larger claws.

Their dark color lets them blend into mud substrates, allowing them to better conceal themselves from predators.

Distribution, Population, and Habitat

Distribution

In the United States, the largest distribution of these crabs is along the Gulf Coast.

Population

This crab population is quite healthy and far from endangered. A large influence here is that there are strict regulations governing the season when you can harvest them and — most importantly — how the creatures are harvested. The crab is one of the few animals that aren’t killed for food. If the fishermen are responsible, the stone crab is safely returned to the wild after its declawing.

Over time, as the creature molts, it will generate new claws. But it’s a slow process that can take up to three years. Older crabs never fully regenerate their claws. The regrowth is greatly influenced by how responsibly fishermen follow regulations concerning claw removal.

Habitat

These crabs live at the bottom of bays, rock jetties, and oyster reefs. You’ll also spot the crabs in limestone sand and seagrass beds. They like to burrow and find refuge from predators. Baby and juvenile stone crabs don’t spend a lot of time digging. Instead, they hide in seagrass or amid rocks.

Predators and Prey

The crab’s predators include octopuses (the crab’s main threat), large fish, sea turtles, and, of course, humans.

In practice, the stone crab has relatively few predators to worry about. The size and power of its claws, as well as its hardened exoskeleton, keep predatory behavior to a minimum. The stone crab uses its powerful claws to defend itself from predators.

Pre-juvenile and larval stages feed on small zooplankton. As they grow, they continue opportunistic carnivore behavior but move on to larger food sources. Adult stone crabs regularly eat hard-shelled clams, small mollusks, acorn barnacles, conch, scallops, and various crustaceans.

Reproduction and Lifespan

After molting, the crabs mate. After fertilization and ovarian development are complete, the female deposits eggs in a sponge or external mass beneath her abdomen. The number of eggs can be up to one million.

At this time, the female is ovigerous (egg-bearing). It is illegal to capture females in this state. (Fishermen can recognize the condition.) Eggs hatch in less than 14 days. The larval stage takes about four weeks. After that, the juvenile metamorphosis stage follows.

The adult male crab will live up to seven years, and the female up to eight.

Fishing and Cooking

The stone crab claw is a seafood favorite. By law, you are only allowed to declaw if the claws are at least 2¾ inches. Only a legal-size claw can be removed before returning the animal to the water.

Crabmeat can be prepared using a variety of recipes. The process is to sauté — quickly cook — the meat so as not to lose flavor and to sustain its flaky texture.