Stone Crab

Stone Crab Image

Menippe mercenaria /
M. adina

ALSO KNOWN AS:

    Florida stone crab, Gulf stone crab

SOURCE:

    U.S. wild-caught from Texas to North Carolina, but mainly in Florida
 

STATUS

  • POPULATION
  • FISHING RATE
  • HABITAT IMPACTS
  • BYCATCH
 

Click the icons to learn more about each criteria

 
 

OVERVIEW

An ovigerous (egg-bearing) female stone crab. These eggs are about halfway through development.

An ovigerous (egg-bearing) female stone crab. These eggs are about halfway through development.

LAUNCH GALLERY

There are three species of true stone crabs: the Florida variety (Menippe mercenaria), the Gulf crab (M. adina), and a hybrid resulting from interbreeding of the Florida and Gulf species. They're found along the Gulf and South Atlantic coast from Texas to Florida, but most are harvested in state waters off Florida. The fishery for stone crabs is unique—fishermen are only allowed to take the large front claws of the stone crab (if they are of legal size) and then must safely return the crab back to the water. If the joint linking the claw to the body is left intact, the claw will regenerate fully after the crab molts a few times (about 3 years). Harvesting stone crabs in this manner helps ensure the long-term sustainability of the stone crab resource and fishery.

As of October 2011, the stone crab fishery is now solely managed by the State of Florida. Florida and the Gulf of Mexico Fishery Management Council previously managed the fishery collaboratively, with Florida in charge of state waters and the Council in charge of federal waters. But because the fishery mostly operates in Florida state waters, the management authorities realized this management process was inefficient and duplicated efforts. To streamline management of the fishery and reduce costs, the Council transferred full management authority disclaimer of the stone crab resource to the State of Florida, which has actively managed the fishery in state waters since 1929. Future management of this valuable fishery should now be more effective and efficient.

Looking Ahead

The stone crab resource is quite resilient because of the nature and management of the fishery. But fishermen, scientists, and managers have expressed concern about too many active traps in the fishery. To address this issue without putting current fishermen out of business, managers and fishermen collaborated to create a trap limitation program. Approved in 2000, the program introduced new licensing and trap limits that will gradually decrease fishing effort over the next 30 years.

 
 
 

LOCATION & HABITAT

Stone crabs are found along the Atlantic and Gulf coasts from Texas to the Carolinas. Crab larvae live in coastal waters and within estuaries. Juveniles hide in crevices in and beneath rock or shell. Adult Gulf stone crabs live on mud flats and oyster reefs in nearshore and estuarine areas. Adult Florida stone crabs live in seagrass beds or on rocky substrate in higher salinity waters. Stone crabs appear to be well suited for their habitat. The dark, unmottled color pattern of the Gulf stone crab helps it blend in with the mud substrates common in the northern Gulf estuaries, and the lighter, spotted color pattern of the Florida stone crab makes it difficult to see in grassy areas.

Stone crab may relocate in response to environmental factors or seasons. Large males travel inshore in the fall to mate with molting females.

 
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BIOLOGY

Stone crabs can live 7 to 8 years and grow to 5-1/2 to 6 inches wide at the carapace (the part of the shell covering the crab’s body). Crabs grow by molting – when their body gets too large for the shell, they burst through it, shed it, and grow a new one.

Stone crabs can only mate immediately after females molt, while their new shell is still soft. Females are able to reproduce when they reach 2.4 inches carapace width; males mature at 2.8 inches carapace width. They usually mate in the fall, often near oyster reefs and seagrass beds. Males deposit spermatozoa in the female, which fertilizes the eggs internally. Females retain the sperm for up to a year, or until the next season's molt. Sperm is stored in two sacs over the winter and used during the following spring and summer spawning season to fertilize the eggs. After the eggs are fertilized, females push them out beneath their abdomen in a “sponge” (a mass of tens of thousands to 1 million eggs). At this stage, females are called “ovigerous,” or egg-bearing. Eggs usually hatch within 2 weeks after this. After about 4 weeks, the larvae develop into juveniles.

Stone crab larvae feed on zooplankton (tiny floating animals). Juvenile and adult stone crabs feed on a variety of shellfish, such as mussels and oysters, and vegetative matter. Stone crabs are able to feed on shellfish because of the enormous crushing force of their claws. They use their pincer claws to cut or tear shell and tissue. Adult filter-feeding fish eat larval stone crab, and larger crabs and large fish such as grouper and black sea bass prey on juveniles. Juvenile stone crabs are more susceptible to predators because they do not yet have their larger adult claws. Octopi and humans prey on adult stone crabs.

 
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PHYSICAL DESCRIPTION

The Gulf stone crab is solid maroon brown. The Florida stone crab is spotted with banded legs. Stone crabs have ten 10 legs: eight for swimming and walking, and two claws for pinching prey or predators. One is a large crusher claw and the other is a smaller pincer claw with numerous small teeth used for cutting. Stone crabs are usually “right-handed,” meaning that the larger crusher claw is usually on the right. The best way to distinguish male and female stone crabs is by their abdomen – females have a wide round abdomen and males have a long narrow abdomen.

 
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OVERVIEW

The Florida Fish and Wildlife Research Institute is responsible for monitoring the commercial stone crab fishery, along with conducting research on the population of stone crabs in Florida.

 
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POPULATION STATUS

Because only the claws of stone crabs are harvested and the crab is returned alive to the water, typical population assessment methods are not relevant for this resource. The status of the stock is best indicated by the stable landings after 1989–1990. The stone crab resource may be resilient because (1) most female stone crabs spawn one or more times before their claws reach legal size, (2) the fishing season is closed during the principal spawning season, and (3) some crabs survive declawing. Stone crabs can regrow either claw if the joint linking the claw to the body is left intact, which is why it’s important for fishermen to correctly break the claws off of the crabs.

 
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Harvesting Stone Crabs

Stone crab are harvested in commercial and recreational fisheries, mainly off Florida’s Gulf Coast and in the Florida Keys. A small number are landed in Texas, Louisiana, Georgia, North Carolina, and South Carolina. Both commercial and recreational fishermen use baited traps to catch stone crabs. Some recreational fishermen also collect crabs by hand using scuba or snorkel gear. In the commercial stone crab fishery, traps are put out in long lines of up to 100 buoyed traps. To reduce bycatch, each plastic trap must have a degradable panel and each wire trap must have at least three unobstructed escape rings (2-3/8 inches inside diameter) on a vertical side of the trap.

Although it is legal to harvest both claws (if they meet the minimum size limit), managers encourage fishermen to only harvest one claw, as taking both leaves the stone crab with few alternatives to defend itself from predators and may slow the regeneration process.

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Management

Who’s in charge? Florida Fish and Wildlife Conservation Commission.

Current management: Florida Fish and Wildlife Conservation Commission Commercial Regulations for Stone Crab disclaimer

  • Seven-month fishing season (October 15 through May 15).
  • A claw (propodus) minimum harvest size (the propodus is the larger, immovable part of the claw). Legal-sized (havestable) claws are 2-3/4 inches (70 millimeters) or greater in propodus length. The measurement is taken from the base of the propodus (at the joint of the elbow) to the outer tip of the propodus.
  • It is illegal to harvest claws from egg-bearing females, easily identifiable by the orange or brown sponge the female carries under her. If a sponge is detected, the crab must be immediately placed back in the water unharmed.
  • Trap specifications.
  • Trap limitation program, which caps the number of traps (and eventually will remove traps from the fishery) to address the problem of excess traps in the fishery.

*A small amount of stone crabs are also harvested in state waters of Texas, Louisiana, Georgia, North Carolina, and South Carolina. The regulations for stone crab harvesting set by most of these states are comparable to Florida’s regulations.

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Annual Harvest

In 2010, over 5.3 million pounds of stone crab claws were landed in the United States. The Florida stone crab fishery provides 98 percent of all stone crab landings in the United States.

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Economy

Stone crab is one of the most economically valuable commercial fisheries in Florida. The 2010 state harvest was worth an estimated $23.8 million.

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Recreational

In Florida, recreational crab fishermen follow similar regulations disclaimer to commercial fishermen: fishing season from October 15 to May 15, no harvesting claws from females with eggs, and a 2-3/4 inch minimum claw size. Recreational fishermen are limited to five traps per person and the traps must meet certain specifications. Recreational fishermen must also have a recreational saltwater fishing license.

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OVERVIEW

Stone crab claws are smooth and rounded. The shells turn bright orange when cooked; the tips remain black. Raw meat is grayish; cooked is white. The meat resembles lobster in appearance and tastes like a cross between crab and lobster—sweet, mild, and firm. The United States is the only supplier of stone crab claws. (Seafood Business, 2011) disclaimer

Of special note are claws called "floaters,” from crabs that have molted recently and are not completely filled with meat. When cooked these claws float to the top, hence the name. They are easy to spot before cooking, as they are much lighter and the shell is often much thinner. Sometimes you’ll see them for sale at a greatly reduced price since they do not contain nearly as much meat. Floaters are not sold to restaurants or sold retail without being clearly identified. (Florida Sea Grant)

 
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SEASONAL AVAILABILITY

Fresh from mid-October to mid-May; frozen year-round.

 
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NUTRITION

Stone crabs are a good, low-fat source of protein, vitamin 6, selenium, and magnesium.

Servings 1
Serving Weight 114 g
Calories 71
Total fat 0 g
Saturated fat 0 g
Cholesterol 53 mg
Sodium 353 mg
Total Carbohydrates 0 g
Protein 17.6 g

Stone Crabs Table of Nutrition

 
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