Brachypelma hamorii is a species of tarantula found in Mexico. It has been confused with B. smithi; both have been called Mexican redknee tarantulas. Many earlier sources referring to B. smithi either do not distinguish between the two species or relate to B. hamorii. B. 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 (2 in) and males having legs up to 75 mm (3 in) long. Mexican redknee tarantulas are a popular choice for enthusiasts. Like most tarantulas, it has a long lifespan.
Te
TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
Ov
OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
No
Not a migrantAnimals that do not make seasonal movements and stay in their native home ranges all year round are called not migrants or residents.
B
starts withBrachypelma 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 (2.0–2.1 in). A sample of 11 males was slightly smaller, with a total body length in the range 46–52 mm (1.8–2.0 in). Although males have slightly shorter bodies, they have longer legs. The fourth leg is the longest, measuring 75 mm (3.0 in) in the type male and 67 mm (2.6 in) in a female. The legs and palps are black to reddish black with three distinctly colored 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 color 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.
B. hamorii and the very similar B. smithi are found along the Pacific Coast of Mexico on opposite sides of the Balsas River basin as it opens onto the Pacific. B. 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.
Their burrows were described in 1999 by a source that did not distinguish between B. hamorii and B. smithi. 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 molt. 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 molting or laying eggs, the entrance is sealed with silk, sometimes supplemented with soil and leaves.
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.
B. 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.
In 1985, B. smithi (then not distinguished from B. hamorii) was placed on CITES Appendix II. Wild-caught specimens shipped for the Chinese market were decreasing in size. The smaller sizes were suspected to be a consequence of a declining population due to excessive export. Exporting is not the only threat, though; some local people have reportedly made a habit of killing these spiders in a nearly systematic way using pesticides, pouring gasoline into burrows, or simply killing migrating spiders on sight. The reasons for these actions seem to be an irrational fear based on myth surrounding B. hamorii and related species. Thus, whether the listing strengthened the wild population or not remains uncertain. The species has been bred successfully in captivity. In 1994, all remaining Brachypelma species were added to Appendix II. Large numbers of Mexican redknee tarantulas caught in the wild continue to be smuggled out of Mexico. At least 3,000 specimens of Mexican tarantulas were reported to have been sent to the United States or Europe a few years prior to 2017, most of which were Mexican redknee tarantulas.
