Cobalt blue tarantula

The cobalt blue tarantula is a medium-sized tarantula with a leg span around 13 cm (5.1 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. The venom of the tarantula is not enough to kill a human, but it can badly sting them and be extremely painful. The venom contains glutamic acid, at 0.97% concentration. Histamine and adenosine were detected at 0.14% and 0.10% with the polyamine spermine noted in trace amounts at 0.002% (Moore et al., 2009).

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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]