Cobalt blue tarantula

The cobalt blue tarantula is a medium-sized tarantula with a leg span around 13  cm (5 in). It is noted for its iridescent blue legs and light gray prosoma and opisthosoma, the latter of which may contain darker gray chevrons.[3][4] Males and females look the same until the ultimate (final) molt of the males. At this point, the male exhibits sexual dimorphism in the form of a light tan or bronze coloration and legginess. Additionally, males gain a palpal bulb on the pedipalps and tibial apophyses (mating hooks). The female eventually becomes larger than the male and lives years longer.[5] The cobalt blue tarantula is a fossorial species and spends nearly all of its time in deep burrows of its own construction.

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  A female (left) and male (right) in courtship in captivity
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  A second-instar spiderling cobalt blue tarantula near burrow

Cobalt blue tarantulas inhabit the tropical rainforests of Southeast Asia,[6] where they construct deep burrows, and generally only leave them to find food.

The cobalt blue tarantula is a mainstay in the pet trade, despite being a fast and defensive tarantula with potent venom.[7] Bites from this species can result in severe muscle cramps and inflammation.[8]