Monday, 10 October 2011

Spiny Orb Weavers, Gasteracantha

Curved Spiny Spider (Gasteracantha arcuata)

Spiny orb-weavers is a common name for Gasteracantha, a genus of spiders. They are also commonly called Spiny-backed orb-weavers, due to the prominent spines on their abdomen. These spiders can reach sizes of up to 30mm in diameter (measured from spike to spike). Although their shell is shaped like a crab shell with spikes, it is not to be confused with a crab spider.
Females are 5–9 millimetres (0.20–0.35 in) long and 10–13 mm (0.39–0.51 in) 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 lives in woodland edges and shrubby gardens.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.

Curved Spiny Spider (Gasteracantha arcuata)

Curved Spiny Spider (Gasteracantha arcuata)

Hasselt's Spiny Spider (Gasteracantha hasseltii)
Black-and-White Spiny Spider (Gasteracantha kuhlii)

1 comment:

  1. Any idea what species that little red one is? It's a fascinating little creature!