''Atergatis floridus'', the floral egg crab, green egg crab, pancake crab, or shawl crab, is a species of tropical

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 ...

crab from the family

Xanthidae Xanthidae is a family (biology), family of crabs known as gorilla crabs, mud crabs, pebble crabs or rubble crabs. Xanthid crabs are often brightly coloured and are highly poisonous, containing toxins which are not destroyed by cooking and for wh ...

. The meat of this crab is toxic, even if cooked, and consumption often results in death.

Description

''Atergatis floridus'' has an oval, relatively narrow carapace which has a smooth surface and smooth margins. The carapace is greenish or greenish-blue-brown and is marked with a pattern which resembles lace and is made up of a fine network of fine white or yellow lines white, resembling a shawl. It has large claws which are equal sizes and which are smooth with black spoon-shaped tips and which may be larger in males than females. The pereiopods are squarish in shape and quite thick with lilac edges and lack hair. The width of the carapace is . The carapace is approximately 1.4 times broader than it is long.

Distribution

''Atergatis floridus'' occurs in the eastern Indian Ocean from south east Asia, south to Australia where it reaches

Rottnest Island Rottnest Island (), often colloquially referred to as "Rotto", is a Islands of Perth, Western Australia, island off the coast of Western Australia, located west of Fremantle. A sandy, low-lying island formed on a base of aeolianite limestone, ...

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

and possibly

Sydney Sydney is the capital city of the States and territories of Australia, state of New South Wales and the List of cities in Australia by population, most populous city in Australia. Located on Australia's east coast, the metropolis surrounds Syd ...

in the east, its range extends eastwards across the western pacific as far as Hawaii.

Biology

''Atergatis floridus'' is an inhabitant of the

neritic The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth. From the point of view of marine biology it forms a relatively stable and well-illuminated ...

zone and prefers coral and rubble. It is largely nocturnal. ''A. floridus'' is host to the

isopod Isopoda is an Order (biology), order of crustaceans. Members of this group are called isopods and include both Aquatic animal, aquatic species and Terrestrial animal, terrestrial species such as woodlice. All have rigid, segmented exoskeletons ...

'' Gigantione hainanensis'' and the

rhizocephala Rhizocephala are derived barnacles that are parasitic castrators. Their hosts are mostly decapod crustaceans, but include Peracarida, mantis shrimps and thoracican barnacles. Their habitats range from the deep ocean to freshwater. Together w ...

barnacles Barnacles are arthropods of the subclass Cirripedia in the subphylum Crustacea. They are related to crabs and lobsters, with similar nauplius larvae. Barnacles are exclusively marine invertebrates; many species live in shallow and tidal water ...

'' Loxothylacus aristatus'', '' Loxothylacus corculum'', '' Sacculina gordonae'', '' Sacculina robusta'', '' Sacculina spinosa'' and '' Sacculina weberi''.

Toxicity

The meat of ''Atergatis floridus'', like that of many related crab species from the family Xanthidae is toxic. The toxins are synthesised by bacteria of the genus ''

Vibrio ''Vibrio'' is a genus of Gram-negative bacteria, which have a characteristic curved-rod (comma) shape, several species of which can cause foodborne infection or soft-tissue infection called Vibriosis. Infection is commonly associated with eati ...

'' which live in

symbiosis Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biological interaction, between two organisms of different species. The two organisms, termed symbionts, can fo ...

with the crab and the poisons are one similar to those found in

puffer fish Tetraodontidae is a family of marine and freshwater fish in the order Tetraodontiformes. The family includes many familiar species variously called pufferfish, puffers, balloonfish, blowfish, blowers, blowies, bubblefish, globefish, swellfish, ...

, i.e.

tetrodotoxin Tetrodotoxin (TTX) is a potent neurotoxin. Its name derives from Tetraodontiformes, an Order (biology), order that includes Tetraodontidae, pufferfish, porcupinefish, ocean sunfish, and triggerfish; several of these species carry the toxin. Alt ...

, and also

saxitoxin Saxitoxin (STX) is a potent neurotoxin and the best-known paralytic shellfish toxin. Ingestion of saxitoxin by humans, usually by consumption of shellfish contaminated by toxic algal blooms, is responsible for the illness known as paralytic she ...

which is the primary toxin involved in

paralytic shellfish poisoning Paralytic shellfish poisoning (PSP) is one of the four recognized syndromes of shellfish poisoning, which share some common features and are primarily associated with bivalve mollusks (such as mussels, clams, oysters and scallops). These shellfi ...

Taxonomy

''Atergatis floridus'' was considered to have a wide

distribution but some authorities consider that the western Indian Ocean specimens belong to a different species, '' Atergatis ocryoe'', which was considered a junior

synonym A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

of ''A. floridus''. ''A. floridus'' ''

sensu stricto ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular c ...

'' is found in the eastern Indian Ocean and Western Pacific.

References

External links

* {{Portal bar, Crustaceans Xanthidae Crustaceans described in 1767 Taxa named by Carl Linnaeus