Missulena

May 01, 2016 Features / Columnists, Interesting Creatures in Guyana

Missulena is a genus of spiders in the mygalomorph family Actinopodidae, sometimes called mouse spiders. There are about 17 known species in this genus, all but one of which are indigenous to Australia. One species, M. tussulena, is found in Chile. The name derives from an old belief, now known to be false, that the spiders dig deep burrows similar to those of mice.

Missulena

There is evidence that the bite of a mouse spider is potentially as serious as that of an Australasian funnel-web spider; however, recorded envenomings by this spider are rare. Funnel-web antivenom has been found to be an effective treatment for serious bites.
Another spider, Scotophaeus blackwalli, shares the nickname “mouse spider”, but does not belong to the genus Missulena and is not considered dangerous.
Mouse spiders are medium-to-large specimens, which range in length from one cm to three cm. Their carapace is glossy, and they have high, broad heads, with eyes spread out across the front of the head. They have short spinnerets, located in the rear of the abdomen.
Mouse spiders exhibit sexual dimorphism, with female spiders being all black; and male spiders having species-specific colouration. The male eastern mouse spider (M. bradleyi) has a bluish patch, and the male red-headed mouse spider (M. occatoria) is brownish or blue-black in colour, with bright red-tinged jaws.
Mouse spiders prey mainly on insects, though they may consume other small animals as opportunity presents. The primary predators of the mouse spider include wasps, bandicoots, centipedes, and scorpions.
The mouse spiders range throughout Australia, with different species being found in different states there. One species is found in Chile, and the nearest related genera of Missulena also occur in South America. This is because they are in place of the Gondwanan fauna. Similar to trapdoor spiders, the mouse spider lives in burrows covered with trapdoors, which can extend to nearly 30 cm (one foot) in depth. Female mouse spiders generally remain in their burrows; the males will wander in search of mates.
The bites of several species of mouse spider in Australia have been found to produce serious symptoms. Most mouse spider bites documented in the medical literature did not require use of antivenom or involve serious symptoms. The venom of the Eastern mouse spider (M. bradleyi) was found to have toxins similar to the robustoxin found in funnel-web venom; and funnel-web antivenom has been found to be effective in treating severe mouse spider bites. Unlike the funnel-web, however, the mouse spider is far less aggressive towards humans, and may often give “dry” bites.
(Source: Wikipedia)