Mexican Redknee TarantulaApril 15, 2021
Brachypelma hamorii is a species of tarantula found in Mexico. It has been confused with Brachypelma smithi; both have been called Mexican Redknee Tarantulas. Brachypelma hamorii is a terrestrial tarantula native to the western faces of the Sierra Madre Occidental and Sierra Madre del Sur mountain ranges in the Mexican states of Colima, Jalisco, and Michoacán. The species is a large spider, adult females having a total body length over 50 mm and males having legs up to 75 mm long. Mexican Redknee Tarantulas are a popular choice for enthusiasts. Like most tarantulas, it has a long lifespan.
Brachypelma hamorii is a large spider. A sample of seven females had a total body length (excluding chelicerae and spinnerets) in the range 52 – 54 mm. A sample of 11 males was slightly smaller, with a total body length in the range of 46 – 52 mm. Although males have slightly shorter bodies, they have longer legs. The fourth leg is the longest, measuring 75 mm in the typical male and 67 mm in a female. The legs and palps are black to reddish black with three distinctly coloured rings, deep orange on the part of the patellae closest to the body with pale orange-yellow further away, pale orange-yellow on the lower part of the tibiae, and yellowish-white at the end of the metatarsi. Adult males have light greyish-red around the border of the carapace with a darker reddish-black marking from the middle of the carapace to the front of the head; the upper surface of the abdomen is black. Adult females vary more in carapace colour and pattern. The carapace may be mainly black with a brownish-pink border, or the dark area may be broken up into a «starburst» pattern with pale orange-yellow elsewhere.
Brachypelma hamorii are found along the Pacific Coast of Mexico on opposite sides of the Balsas River basin as it opens onto the Pacific. Brachypelma hamorii is found to the north, in the states of Colima, Jalisco, and Michoacán. The natural habitat of the species is in hilly deciduous tropical forests. It constructs or extends burrows under logs, rocks, and tree roots, among thorny shrubs and tall grass.
The deep burrows keep them protected from predators, such as the white-nosed coati and enable them to ambush passing prey. The females spend the majority of their lives in their burrows, which are typically located in, or not far from, vegetation, and consist of a single entrance with a tunnel leading to one or two chambers. The entrance is just slightly larger than the body size of the spider. The tunnel, usually about three times the tarantula’s leg span in length, leads to a chamber that is large enough for the spider to safely moult. Further down the burrow, via a shorter tunnel, a larger chamber is located where the spider rests and eats its prey. When the tarantula needs privacy, e.g. when moulting or laying eggs, the entrance is sealed with silk, sometimes supplemented with soil and leaves.
Brachypelma hamorii grows very slowly and matures relatively late. The females of this species can live up to 30 years, but the males tend to live for only 5 years or so.
Like most New World tarantulas, they kick urticating hairs from their abdomens and their back legs if disturbed, rather than bite. They are only slightly venomous to humans and are considered extremely docile, though, as with all tarantulas, their large fangs can cause very painful puncture wounds, which can lead to secondary bacterial infection if not properly treated and allergies may intensify with any bite.