A Spider & A Scorpion

Meet the fabulous Markosha – a Mexican redknee tarantula (Brachypelma smithi). This female spider has been living at the Darwin museum “Nature Live Exhibition” for more than 6 years.

It’s interesting to know, that female tarantulas tend to live a lot longer (up to 20 years and even more) than males, as the latter die relatively soon after maturing. Apart from that sexual dimorphism is not very pronounced: males tend to be a little smaller than females, they usually have slightly shorter bodies and longer legs.

Every year Markosha likes to change her “look”. We get many complaints from our visitors about spider cannibalism, so we put a sign explaining that it’s not a dead tarantula, it’s simply an old “outfit” of our spider-lady. 

The scientific name for the process of shedding the exoskeleton, which allows spiders to grow, is called molting. Our Markosha is a mature tarantula who does shedding only once a year, compared to young who do it more frequently as a part of the growing up process. An adult tarantula does it to replace lost limbs or lost urticating hairs. Right before the process begins, Markosha stops feeding and becomes more lethargic, her exoskeleton takes on a darker shade. If a tarantula previously used its urticating hairs, the bald patch turns from a peach color to deep blue.

The bite of a tarantula is unpleasant, but not dangerous for humans. Maybe, that’s why they are so popular as pets. However, the hairs they brush off when stressed may cause allergy, so we don’t allow tactile contact with visitors, demonstrating our lovely Markosha from a safe distance.

Our Markosha belongs to the species of a terrestrial tarantula native to the Pacific coast of the Mexican state of Guerrero. The natural habitat of the species is in hilly deciduous tropical forests. It constructs or extends burrows under rocks and tree roots, among dense thickets and deciduous forests. The deep burrows keep them protected from predators and enable them to ambush passing prey. The females spend the majority of their lives in their burrows. When the tarantula needs privacy, e.g. when molting or laying eggs, the entrance is sealed with silk, sometimes supplemented with soil and leaves.

Another one extraordinary lady, Markosha’s neighbor, is Naesha – a female scorpion. The two have something in common – they both are not insects, but belong to the class Arachnida.

Scorpions are predatory arachnids of the order Scorpiones, who have 8 legs and are easily recognized by the pair of grasping pedipalps and the narrow, segmented tail, ending with a venomous stinger. Although, our Naesha has lived with us for quite some time and has become “domestic”, she is a lady with an attitude, therefore our visitors can admire her from a safe distance.

In 2015 Naesha became a happy mother of 22 baby scorpions. The size of the litter depends on the species and environmental factors and can range from 2 to more than 100 scorpions (the average litter is about 8).

Unlike the majority of species in the class Arachnida, scorpions seem to be universally viviparous, which means that embryos develop inside the body of the parent, leading the latter to the process of giving birth. Soon after the birth the young climb onto their mother’s back and get carried around until they have undergone at least one molt (around 2 weeks). Before the first molt, young scorpions cannot survive naturally without the mother, since they depend on her for protection and to regulate their moisture levels. It takes 2-3 years for them to mature with having to undergo several molts.

Although, scorpions are not usual inhabitants of cities, their number in industrial and residential areas has greatly increased for the past several decades due to the lack of predators, readily available shelter, and abundance of insect prey.