Thelacantha

Thelacantha
T. brevispina, female from Taiwan
T. brevispina, male from Japan
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Arachnida
Order:	Araneae
Infraorder:	Araneomorphae
Family:	Araneidae
Genus:	Thelacantha Hasselt [fr], 1882[1]
Species:	T. brevispina
Binomial name
Thelacantha brevispina (Doleschall, 1857)
Synonyms[1]
Plectana brevispina Doleschall, 1857[2]

Thelacantha (Asian spinybacked orbweaver) is a genus of orb-weaver spiders containing the single species, Thelacantha brevispina. It was first described by A. W. M. van Hasselt [fr] in 1882,^[3] and has been found in Australia, Madagascar, the Indian subcontinent and Southeast Asia, as well as parts of Japan.^[4][1] It has also been introduced into Hawaii.^[5] T. brevispina is closely related those in the genus Gasteracantha, and was briefly synonymized with it in 1859,^[6] but revalidated in 1974.^[7] Saito described three other Thelacantha species in 1933,^[8] which were later synonymized with T. brevispina.^[1]

Females grow to about 6 to 10 millimetres (0.24 to 0.39 in) long, while males reach a size of 3 to 5 millimetres (0.12 to 0.20 in).^[4] Females have six abdominal spines ending in distinct sharp points. Most have two large white spots on the upper surface of their abdomens, which are otherwise mottled with black, brown, and white patterns.^[5]

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  Female at Molokai, Hawaii

T. brevispina has often been misidentified as Gasteracantha mammosa, which is now G. cancriformis. It has gone through a checkered name history, with many synonyms:^[1]

• Diversity of females from Japan
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• Gasteracantha cancriformis

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