Mangrove crabs are semi-terrestrial, meaning they live both in the sea and on the land. These crabs can be found in tidal mangrove mud flatsalong the Atlantic Coast from Florida to southern coast of Brazil. They typically burrow themselves in sediment and eat mostly decaying plant litter.
These crabs have a curved oval shell or carapace that is slightly egg shaped that can vary from blue to yellow in colour. They have 8 pinkish legs and 2 long pincers. Mangrove crabs are boiled whole or baked in a casserole with salt, onions, garlic, tomatoes, peppers and some fresh herbs. The crab meat can also be used for preparation of different dishes.
Mangrove crabs have highly variable life cycles that are dependent on different biotic and abiotic factors, such as precipitation, relative humidity, and the lunar cycle. They are slow-growing and long-lived; they have been known to live for more than 10 years.
These crabs mate at the time of maturity, which is approximately 3 years of age. Females are smaller than males; this is because the development of reproductive tissues required more energy for females, leaving less energy available for continued body growth. They grow through a process known as molting - regularly shedding their shell and growing a new, larger one. They continue to molt and grow after they have reached sexual maturity. During the breeding season, the crabs leave their borrows in a phenomenon characterized by mass mate-searching events. Once mating/fertilization has occurred, females spawns in the water. The larvae released during the rainy season develop in offshore waters and return to coastal waters five to eight weeks after larval release.
Mangrove crabs are important fishery resources in all Brazilian coast, mainly in the north and northeast where many fishermen depend upon their catch. In addition to its social and economic importance, the mangrove crab is a “keystone” specie in ecosystem, they playing an important role in the processes of nutrient cycling and energy transfer.
Artisanal Hand Collecting
Fish harvesters travel to mangrove habitat in estuaries using small boats and catch crabs by hand. They insert one arm into the crabs’ burrow and remove it with their hand or with the aid of a hooked stick.