Delena cancerides, the flat huntsman spider or social huntsman spider, is a large, brown huntsman spider

Huntsman spider

Sparassidae are a family of spiders known as Huntsman spiders because of their speed and mode of hunting. They also are called giant crab spiders, because of their size and appearance. Larger species sometimes are referred to as wood spiders, because of their preference for woody places...

 native to Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. It has been introduced

Introduced species

An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...

 to New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

, where it is sometimes known as the Avondale spider. This was the species used in the beginning of the movie Spider-Man

Spider-Man (film)

Spider-Man is a 2002 American superhero film, the first in the Spider-Man film series based on the fictional Marvel Comics character Spider-Man. It was directed by Sam Raimi and written by David Koepp...

and widely in Arachnophobia

Arachnophobia (film)

Arachnophobia is a 1990 American comedy horror film directed by Frank Marshall and starring Jeff Daniels and John Goodman. It was the first film released by Hollywood Pictures....

, but it is generally considered harmless to humans.

Behavior

Highly unusual among spiders, the flat huntsman spider is a social species, even sharing prey. They are often found under loose bark (their flat shape is an adaption for this) in colonies up to 300, but they are highly aggressive and commonly cannibalistic toward members from other colonies. They hunt their food rather than spin webs for it. They are timid towards humans and bites are infrequent, and when they occur, symptoms are usually very minor.

Distribution

The species is found all over Australia, including Tasmania

Tasmania

Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...

, and is quite common in South Australia

South Australia

South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...

. It was accidentally found in 1924. Its range in New Zealand has expanded only slowly out of Avondale

Avondale, Auckland

Avondale is a suburb of Auckland, New Zealand, located in the Whau ward, one of the thirteen administrative divisions for the Auckland Council. It is commonly considered to be part of West Auckland. It was originally called "Te Whau", which is the common name, of Māori origin, for Entelea...

, a suburb of Auckland

Auckland

The Auckland metropolitan area , in the North Island of New Zealand, is the largest and most populous urban area in the country with residents, percent of the country's population. Auckland also has the largest Polynesian population of any city in the world...

, hence the alternative New Zealand common name. Species have been found as far down the country as the Otago region.

Appearance and genetics

The body of the spider may be up to 4.5 centimetres (1.8 in) long, is light brown and covered in dense, fine hairs. The legs are also hairy, and can have a span up to 20 centimetres (7.9 in). Females are larger than males.

Various populations show major differences in the chromosome

Chromosome

A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...

s, leading to the recognition of several "chromosomal subspecies

Subspecies

Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

", but these hybridize where in contact and there is little genetic divergence

Genetic divergence

Genetic divergence is the process in which two or more populations of an ancestral species accumulate independent genetic changes through time, often after the populations have become reproductively isolated for some period of time...

.