Gasteracantha
Gasteracantha is a genus of orb-weaver spiders first named by Carl Jakob Sundevall in 1833. Species of the genus are known as spiny-backed orb-weavers, spiny orb-weavers, or spiny spiders. The females of most species are brightly colored with six prominent spines on their broad, hardened, shell-like abdomens. The name Gasteracantha is derived from the Greek (), meaning "belly, abdomen", and (), meaning "thorn, spine". Spiny-backed orb-weavers are sometimes colloquially called "crab spiders" because of their shape, but they are not closely related to the true crab spiders. Other colloquial names for certain species include thorn spider, star spider, kite spider, or jewel spider. Members of the genus exhibit strong sexual dimorphism. Females are several times larger than males, which lack prominent spines or bright colors. Other genera in the same family are also known as spiny orb-weavers. Distribution Gasteracantha species are distributed worldwide in tropical and subtropical climates. The genus is most diverse in tropical Asia, from India through Indonesia. One species, G. cancriformis, occurs in the Americas. Predators and defense mechanisms Some species of orb-weavers use stridulation as an antipredator defense mechanism. Orb-weavers' bites are generally harmless to humans. Taxonomy and systematics Gasteracantha has a complex taxonomic history, and