''Zebrida'' is a small

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of distinctive striped

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 ...

s, known as zebra crabs, that live in association with

sea urchin Sea urchins () are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to . The spherical, hard shells (tests) of ...

s 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 ...

Description

''Zebrida'' was described by Arthur Adams as "a torpid, though elegant little crustacean". It is "the most unusual" of the genera in the subfamily Eumedoninae, with long spines projecting from the body, and a distinctive pattern of stripes across the

exoskeleton An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton (endoskeleton) in for example, a human. In usage, some of the ...

Taxonomy and distribution

The genus was thought to be

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

for a long time, but in 1999, Peter Ng & Diana Chia recognised two additional species, bringing the total number to three. * ''

Zebrida adamsii ''Zebrida adamsii'' is a distinctively striped species of crab that lives in association with a sea urchin in the Indo-Pacific region. It is cryptically coloured with vertical stripes and has special adaptations to its legs to enable it to cl ...

'' is widespread in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

and western

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

, from

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. * '' Zebrida brevicarinata'' is only known from

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

. * '' Zebrida longispina'' is only known from Western Australia.

Ecology and life cycle

Crabs of the genus ''Zebrida'' live, often in pairs, in association with

s, including ''

Toxopneustes pileolus ''Toxopneustes pileolus'', commonly known as the flower urchin, is a widespread and commonly encountered species of sea urchin from the Indo-West Pacific. It is considered highly dangerous, as it is capable of delivering extremely painful and me ...

'', ''

Toxopneustes elegans ''Toxopneustes elegans'' is a species of sea urchin endemic to Japan. Like the closely related flower urchin, they are venomous. Taxonomy ''Toxopneustes elegans'' is one of the four species in the genus ''Toxopneustes''. It was first described b ...

'', ''

Tripneustes gratilla ''Tripneustes gratilla'', the collector urchin, is a species of sea urchin. Collector urchins are found at depths of in the waters of the Indo-Pacific, Hawaii, the Red Sea, and The Bahamas. They can reach in size. Description Collector urchin ...

'', ''

Diadema setosum ''Diadema setosum'' is a species of long-spined sea urchin belonging to the family Diadematidae. It is a typical sea urchin, with extremely long, hollow spines that are mildly venomous. ''D. setosum'' differs from other '' Diadema'' with five, ...

'', ''

Asthenosoma ijimai ''Asthenosoma ijimai'' is a species of sea urchin of the family Echinothuriidae. Their armour is covered with spines. It is placed in the genus Asthenosoma and lives in the sea. Asthenosoma ijimai was first scientifically described in 1897 by Yo ...

'', '' Salmacis bicolor'', ''

Salmacis virgulata Salmacis ( grc, Σαλμακίς) was an atypical Naiad nymph of Greek mythology. She rejected the ways of the virginal Greek goddess Artemis in favour of vanity and idleness. Mythology Ovid's version Salmacis' attempted rape of Hermaphrodi ...

'', ''

Heliocidaris crassispina ''Heliocidaris'' is a genus of sea urchins, part of the familia Echinometridae. Characteristics This genus is typical of west Pacific Ocean (Japan to New Zealand), in particular in Australia. Some species are edible. List of species This ge ...

'', ''

Pseudocentrotus depressus ''Pseudocentrotus depressus'', commonly known as the pink sea urchin, is a species of sea urchin, one of only two species in the genus ''Pseudocentrotus''. It was first described in 1864 by the American marine zoologist Alexander Agassiz as ' ...

'' and a species of ''

Acanthocidaris ''Acanthocidaris'' is a genus of echinoderms belonging to the family Cidaridae. The species of this genus are found in Australia, Indian Ocean and Malesia Malesia is a biogeographical region straddling the Equator and the boundaries of the ...

''. ''Z. adamsii'' passes through four zoeal phases, and one megalopa phase before reaching the mature condition.

References

External links

* * {{Taxonbar, from=Q18580803 Pilumnoidea