''Scylla serrata'' (often called

mud crab Mud crab may refer to any crab that lives in or near mud, such as: *''Scylla serrata'' *''Scylla tranquebarica'' *''Scylla paramamosain'' *''Scylla olivacea'' *Members of the family Panopeidae, such as ''Panopeus herbstii'' *Members of the family ...

mangrove crab Mangrove crabs are crabs that live among mangroves, and may belong to many different species and even families. They have been shown to be ecologically significant in many ways. They keep much of the energy within the forest by burying and cons ...

, although both terms are highly ambiguous, and black crab) is an ecologically important

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of crab found in the

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

and

mangrove A mangrove is a shrub or tree that grows in coastal saline water, saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evoluti ...

s of Africa, Australasia, and Asia. In their most common forms, their shell colours vary from a deep, mottled green to very dark brown.

Distribution

The natural

range Range may refer to: Geography * Range (geographic), a chain of hills or mountains; a somewhat linear, complex mountainous or hilly area (cordillera, sierra) ** Mountain range, a group of mountains bordered by lowlands * Range, a term used to i ...

of ''S. serrata'' is in the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

. It is found from South Africa, around the coast of the Indian Ocean, where it is especially abundant in

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

, to the Southeast Asian Archipelago, as well as from southern Japan to south-eastern Australia, northern New Zealand, And as far east as Fiji and Samoa. The species has also been introduced to Hawaii and

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

. In

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

, mud crabs are colloquially known as Samoan crabs, as they were originally imported from American Samoa. As these crabs are known for their robust size and dense meat content, they have been greatly sought after over the years. As a result of overcrabbing, local government efforts have restricted harvesting of crabs smaller than 6 inches (width across back) and to harvest females of any size is illegal.

Ecology

A study on tidal flats in Deception Bay in Queensland found juvenile crabs ( carapace width) were resident in the

zone, remaining there during low tide, while subadults () migrated into the

intertidal zone The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species o ...

to feed at high tide and retreated to subtidal waters at low tide. Adults ( and larger) were caught mainly below the low-tide mark, with small numbers captured in the intertidal zone at high tide. These crabs are highly

cannibalistic Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species In biology, a species is the basic ...

in nature; when crabs undergo molting, other hard-shelled ones sometimes attack the molting crabs and devour them. The females can give birth to a million offspring, which can grow up to in size and have a shell width up to wide.

References

External links

Australia: Queensland government page on mangrove crab aquacultureCycle of the mud crabLife Cycle of the Mud Crab – Fishnote No.11 March 2007, Northern Territory
{{Taxonbar, from=Q3544834 Portunoidea Edible crustaceans Commercial crustaceans Crustaceans described in 1775 Taxa named by Peter Forsskål Australian cuisine