One of the teachers at school found this redback spider in a petri dish. He shared the find with the faculty to warn them of the dangers of the spider. The redback is a native of Australia and belongs to the genus of spiders that include the North American black widow and 31 other species found all over the world. The redback was accidentally introduced to Osaka in a cargo of wood chips.
They are poisonous and because they like to make their messy nests near human habitation, humans are bitten quite often. The venom causes extreme pain among other symptoms, but usually not death, especially since the development of an anti venom.
The most interesting thing about their natural history is the difference between males and females. The females are larger and have the distinctive red back. They eat the males during copulation and can save the sperm for up to two years to use later. The males live nearby the females, scrounging scraps from the insects and small vertebrates the female captures. Are humans evolving to this?
Thanks to Paul for sharing his find.