Austracantha is a genus of spider with a single species, Austracantha minax, commonly known as the jewel spider or the Christmas spider. It is a member of the family Araneidae (the orb-weavers) and is endemic to Australia. They are relatively small spiders, reaching a maximum total body length of only around 12 mm (0.47 in) for females, and 5 mm (0.20 in) for males. Their abdomen has six distinctive projections ("spines") that makes them easy to identify. They are predominantly a shiny black, with variable white, yellow, and orange patterns. Melanistic forms also occur during autumn. They are facultatively gregarious, and can be found in large aggregations of overlapping orb webs. They feed on small flying insects that get entangled in their webs. They are harmless to humans, though the we