''Idiosoma'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

n armoured trapdoor spiders that was first described by

Anton Ausserer Anton Ausserer (5 July 184320 July 1889)Maurer, Ferdinand: ''Nachruf an Dr. Anton Ausserer.'' Programm des kk. acad. Gymnasiums in Grätz. Graz 1890 was an Austrian natural history, naturalist specialising in spiders.Bonnet, Pierre: Bibliographi ...

in 1871. Originally placed with the Ctenizidae, it was moved to the armoured trapdoor spiders in 1985. The name is derived from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

('' idios''), meaning "individual, unique", and ('' soma''), meaning "body", referring to the distinctive structure of the abdomen.

Description

The skin of their

abdomen The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...

is hardened, with a flattened end and deep grooves running along the sides. The thickened skin helps to reduce water loss in its dry habitat. It also serves as a kind of plug to shield itself from predators. This phenomenon is called phragmosis and occurs in perfection in the spider genus '' Cyclocosmia'' ( Ctenizidae). However, some parasitic wasps have evolved paper-thin abdomens and long, slender

ovipositor The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typica ...

s and lay their eggs on the softer skin at the front of the spider's abdomen.Australian Museum Online Females of the black rugose trapdoor spider (''Idiosoma nigrum'') can grow up to long. Males can grow up to in body length.

Behaviour

The spider digs burrows up to deep, where the temperature is relatively constant through the seasons. When prey triggers any of the trip-lines radiating from the burrow's entrance, the spider runs out of the burrow to capture

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

beetle Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

cockroach Cockroaches (or roaches) are insects belonging to the Order (biology), order Blattodea (Blattaria). About 30 cockroach species out of 4,600 are associated with human habitats. Some species are well-known Pest (organism), pests. Modern cockro ...

es,

millipede Millipedes (originating from the Latin , "thousand", and , "foot") are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name derive ...

s or

moth Moths are a group of insects that includes all members of the order Lepidoptera that are not Butterfly, butterflies. They were previously classified as suborder Heterocera, but the group is Paraphyly, paraphyletic with respect to butterflies (s ...

s. This is unlike many trapdoor spiders that very rarely leave their burrow. Males actively look for females, and mating takes place in the female's burrow. She lays her eggs during late spring and early summer. The spiderlings hatch in mid-summer, and stay inside the burrow until early winter, when the weather becomes more humid.

Species

the genus contained twenty-nine species from the states of

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

(NSW),

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

(SA),

Victoria Victoria most commonly refers to: * Queen Victoria (1819–1901), Queen of the United Kingdom and Empress of India * Victoria (state), a state of Australia * Victoria, British Columbia, Canada, a provincial capital * Victoria, Seychelles, the capi ...

(VIC) or

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 ...

(WA): *'' Idiosoma arenaceum'' Rix & Harvey, 2018 – WA *'' Idiosoma berlandi'' (Rainbow, 1914) – NSW *'' Idiosoma castellum'' (

Main Main may refer to: Geography *Main River (disambiguation), multiple rivers with the same name *Ma'in, an ancient kingdom in modern-day Yemen * Main, Iran, a village in Fars Province *Spanish Main, the Caribbean coasts of mainland Spanish territ ...

, 1986) – WA *'' Idiosoma clypeatum'' Rix & Harvey, 2018 – WA *'' Idiosoma corrugatum'' Rix & Harvey, 2018 – SA *'' Idiosoma cupulifex'' (Main, 1957) – WA *'' Idiosoma dandaragan'' Rix & Harvey, 2018 – WA *'' Idiosoma formosum'' Rix & Harvey, 2018 – WA *'' Idiosoma galeosomoides'' Rix, Main,

Raven A raven is any of several large-bodied passerine bird species in the genus '' Corvus''. These species do not form a single taxonomic group within the genus. There is no consistent distinction between crows and ravens; the two names are assigne ...

& Harvey, 2017 – WA *'' Idiosoma gardneri'' Rix & Harvey, 2018 – WA *'' Idiosoma gutharuka'' Rix & Harvey, 2018 – WA *'' Idiosoma incomptum'' Rix & Harvey, 2018 – WA *'' Idiosoma intermedium'' Rix & Harvey, 2018 – WA *'' Idiosoma jarrah'' Rix & Harvey, 2018 – WA *'' Idiosoma kopejtkaorum'' Rix & Harvey, 2018 – WA *'' Idiosoma kwongan'' Rix & Harvey, 2018 – WA *'' Idiosoma manstridgei'' ( Pocock, 1897) – WA *'' Idiosoma mcclementsorum'' Rix & Harvey, 2018 – WA *'' Idiosoma mcnamarai'' Rix & Harvey, 2018 – WA *'' Idiosoma montanum'' (Faulder, 1985) – NSW *''

Idiosoma nigrum ''Idiosoma nigrum'', also called black rugose trapdoor spider, occurs only in south-western Western Australia, in dry woodlands east of the Darling Scarp and north to Moore River (Western Australia), Moore River. Females can reach a length of ab ...

'' Main, 1952 – WA *'' Idiosoma occidentale'' ( Hogg, 1903) – WA *'' Idiosoma planites'' (Faulder, 1985) – NSW *'' Idiosoma rhaphiduca'' (Rainbow & Pulleine, 1918) – WA *'' Idiosoma schoknechtorum'' Rix & Harvey, 2018 – WA *'' Idiosoma sigillatum'' (O. Pickard-Cambridge, 1870) (

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

) – WA *'' Idiosoma smeatoni'' (Hogg, 1902) – SA *'' Idiosoma subtriste'' (O. Pickard-Cambridge, 1877) – SA *'' Idiosoma winsori'' (Faulder, 1985) – VIC

Description

Behaviour

Species

References

Further reading