Spiders

RED BACK SPIDER

This is a dangerous spider found in Australia, whose bite can cause severe pain for more than 24 hours. However, only the female bite is fatal, and as they rarely leave their nests, their bites are rare. The Red back spider gets its name from the red stripe located on the upper side of its abdomen. The female can be as large as a centimeter while the male typically measure 3 – 4 millimeter in length.

The female exhibits sexual cannibalism while mating by killing and eating the male as they mate. The mating is started by the male who makes overtures to the female to try and discover whether she is interested in mating. If she accepts, to occupy her attention during the act, it offers the female its abdomen, which she digests. In the meantime, the male inserts its palp into the female from which the sperm is inserted into the female.

After mating the female can store the sperm and use it for up to two years to lay a number of batches of eggs. Each batch contains 250 eggs and is suspended in sacs within the web. This process is repeated every two to three weeks and the eggs hatch in two to four weeks. The young ones are cannibalistic as well and easily eat other young ones. The females mature in four months while the males do so in three months. Females live for up to three years while the males live for up to seven months.

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