Gasteracantha cancriformis (the crab spider, spiny-backed orbweaver, spiny orbweaver spider, crab-like orbweaver spider, crab-like spiny orbweaver spider, jewel spider, spiny-bellied orbweaver, jewel box spider or smiley face spider) is a species of spider.
1. Gasteracantha - Greek, γαστήρ (gaster, "belly") + "ἄκανθα" (akantha, "thorn").
2. Cancriformis - Latin, cancer, "crab" + forma, "shape, form, appearance."
Females are 5 to 9 mm long and 10 to 13 mm wide. The six abdominal spine-like projections on the abdomen are characteristic. The carapace, legs and underside are black with white spots under the abdomen. Variations occur in the colour of the upperside of the abdomen with black spots on white to yellow ground colour and red spines or yellow instead of white. Spines are sometimes black. Like in many other spiders, males are much smaller (2 to 3 mm long) and longer than wide. They are similar to the females in colour but have a gray abdomen with white spots and the spines are reduced to four or five stubby projections.
It is found across the southern part of the United States from California to Florida, as well as in Central America, Jamaica, Cuba, Dominican Republic, South America and certain islands in the Bahamas.
It lives in woodland edges and shrubby gardens. Many of the studies on this spider have taken place in citrus groves in Florida. They frequently live in trees or around trees in shrubs.
This species of spider does not live very long. In fact, the lifespan only lasts until reproduction, which usually takes place the spring following the winter when they hatched. Females die after producing an egg mass, and males die six days after a complete cycle of sperm induction to the female.
This spider adds little tufts of silk to its web. These seem not to function to attract prey. Possibly one function is to warn larger animals not to accidentally destroy the web, or to act as camouflage.
Top, from Hernando, Florida
From Austin, Texas
- ^ Eberhard 2006