''Lybia tessellata'' is a

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 small

crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Xanthidae Xanthidae is a 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 which no antidote is ...

. It is found in shallow parts of the tropical Indo-Pacific Ocean. Like other members of the genus ''

Lybia ''Lybia'' is a genus of small crabs in the family Xanthidae. Their common names include boxer crabs, boxing crabs and pom-pom crabs. They are notable for their mutualism with sea anemones, which they hold in their claws for defense. In retur ...

'', it is commonly known as the pom-pom crab or boxer crab because of its habit of carrying a

sea anemone Sea anemones are a group of predation, predatory marine invertebrates of the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemones are classifi ...

around in each of its claws, these resembling pom-poms or

boxing glove Boxing gloves are cushioned gloves that fighters wear on their hands during boxing matches and practices. Unlike "fist-load weapons" (such as the ancient cestus) which were designed as a lethal weapon, modern boxing gloves are non-lethal, desig ...

Description

''Lybia tessellata'' is a small crab growing to a width of about . The

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

is trapezoid in shape and the margin has a distinct tooth-shaped projection on either side, just behind the short-stalked eye. The surface of the carapace is marked into several differently coloured, geometric regions by a network of dark lines giving it the appearance of

stained glass Stained glass is coloured glass as a material or works created from it. Throughout its thousand-year history, the term has been applied almost exclusively to the windows of churches and other significant religious buildings. Although tradition ...

. The chelipeds do not have the broad

chelae A chela ()also called a claw, nipper, or pinceris a pincer (biology), pincer-like organ at the end of certain limbs of some arthropods. The name comes from Ancient Greek , through New Latin '. The plural form is chelae. Legs bearing a chela are ...

(claws) typical of decapod crabs. Instead they are slim and each has a fine finger bearing eight or nine spines. The front pair of walking legs is smaller than the other three pairs but all are much larger than the chelipeds. The legs are banded with dark transverse lines, speckled with white spots and clad in sparse, short hairs. The claws at their ends are long and thin.''Lybia tessellata''
Marine Species Identification Portal. Retrieved February 20, 2012.

Distribution and habitat

''Lybia tessellata'' is found in shallow water in the 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 ...

region, its range extending from the

Red Sea The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; T ...

and the East African coast to

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

and

New Guinea New Guinea (; Hiri Motu Hiri Motu, also known as Police Motu, Pidgin Motu, or just Hiri, is a language of Papua New Guinea, which is spoken in surrounding areas of Port Moresby (Capital of Papua New Guinea). It is a simplified version of ...

. It is found on sandy and gravelly seabeds, where it is well camouflaged, and on live corals where it clings with its long, thin legs.''Lybia tessellata''
Marine Life of the Maldives. Retrieved February 20, 2012.

Biology

''Lybia tessellata'' is an omnivore. It carries a small

, usually '' Bunodeopsis'' spp. or '' Triactis producta'', in each chela, holding its chelipeds out horizontally while moving around. If attacked by a potential

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

, it will threaten the aggressor with an anemone, the tentacles of which are well armed with

cnidocyte A cnidocyte (also known as a cnidoblast or nematocyte) is an explosive cell containing one large secretory organelle called a cnidocyst (also known as a cnida () or nematocyst) that can deliver a sting to other organisms. The presence of this ce ...

s (stinging cells). It is unable to feed itself with its chelae and uses the tentacles of the anemones to collect food particles which it then removes with its mobile

maxilliped An appendage (or outgrowth) is an external body part, or natural prolongation, that protrudes from an organism's body. In arthropods, an appendage refers to any of the homologous body parts that may extend from a body segment, including anten ...

s. The red

eggs Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...

of ''Lybia tessellata'' are carried around on the female's abdomen where they are brooded.

Use in aquaria

''Lybia tessellata'' is well suited to being kept in a

reef aquarium A reef aquarium or reef tank is a marine aquarium that prominently displays live corals and other marine invertebrates as well as fish that play a role in maintaining the tropical coral reef environment. A reef aquarium requires appropriately ...

, though its small size and

cryptic Cryptic may refer to: In science: * Cryptic species complex, a group of species that are very difficult to distinguish from one another * Crypsis, the ability of animals to blend in to avoid observation * Cryptic era, earliest period of the Earth ...

appearance may make it better suited to a small tank where it can be better observed. It is compatible with most other tank inhabitants but may be attacked by predatory fish.''Lybia tessellata'' - Pom Pom Crab
Blue Zoo Aquatics. Retrieved February 20, 2012. It is a shy species and easier to find at night when the tank lights are off.

References

External links

Video clip showing crab moving around * {{Taxonbar, from=Q13598593 Xanthoidea Crustaceans described in 1812 Taxa named by Pierre André Latreille