Brachypelma hamorii

This large spider lives in Mexico.

It has bright orange rings on its legs. The spider lives in holes in the ground. It makes these holes under rocks or logs.

These holes keep the spider safe from animals. The spider must shed its old skin to grow. This is called molting. The spider stays very still during this time. A female spider can live for 30 years. This is a very long time for a spider!

The *Brachypelma hamorii* is a large spider from Mexico.

People often call it the Mexican redknee tarantula. For a long time, people thought it was a different spider. They called it *B. smithi*. Now, scientists know they are two different species. They can tell them apart by looking at their DNA. DNA is the tiny code inside living things.

These spiders live in hilly forests in Mexico. They make deep burrows under logs or rocks. The burrows have tunnels and small rooms. Females spend most of their lives in these homes.

To grow, the spider must go through molting. This is a way to shed its old skin. The old skin is like a hard shell. It cannot stretch, so the spider must replace it. Before molting, the spider stops eating. It turns on its back to push out the old skin. After molting, the spider's fangs are soft. It may not eat for a month. Females can live up to 30 years. Males usually live for only five years. This species is vulnerable. This means there are not many left in the wild.

The *Brachypelma hamorii* is a large, colorful spider from Mexico.

People often call it the Mexican redknee tarantula. This spider is a terrestrial species, which means it lives on the ground. It is found in the western parts of the Sierra Madre Occidental and Sierra Madre del Sur mountain ranges. These spiders live in hilly tropical forests with many trees. They stay safe by making deep burrows under logs, rocks, or tree roots.

These homes have tunnels and small rooms for resting or eating.

To grow, this spider must go through a thing called molting. Because the spider has a hard outer shell, it cannot simply stretch. The spider must grow a new shell underneath the old one. First, the spider stops eating to save up energy. Its abdomen often turns dark right before the change happens. Then, the spider flips onto its back to wiggle out of the old skin. This can take several hours of hard work. After molting, the spider's fangs are very soft. It might not eat for a whole month while they harden.

For a long time, scientists were confused about this spider. They thought it was a different species named *B. smithi*. In 1997, researchers Marc Tesmoingt, Frédéric Cleton, and Jean Verdez first described *B. hamorii*. They found it was very close to the other species. They noticed differences in the female's body parts to tell them apart. Later, in 2017, J. Mendoza and O. Francke helped clear up the confusion. They used DNA barcoding to prove they were truly different. This method looks at tiny parts of a gene to find a match.

There are many specific details that make this spider unique. Adult females can have a body length between 4.5 and 5.5 centimeters. Males are often smaller but have much longer legs. The fourth leg is the longest on their bodies. Their legs have bright orange or yellow rings on them. These colors stand out against their black or reddish-black legs. Females can live a very long time, up to 30 years. Males usually live for only about 5 years.

Knowing about these spiders helps us understand how to protect them. This species is considered vulnerable in the wild. This means their numbers are dropping and they need our help. Some people have harmed them because of myths or fear. Others have taken too many from the wild to sell them. Many of these spiders are even smuggled out of Mexico. We can learn a lot by studying how they live in their natural homes. By watching how they build burrows, we see how they stay safe from predators.

The *Brachypelma hamorii* is a large, terrestrial tarantula native to Mexico.

It is commonly known as the Mexican redknee tarantula. This species is considered vulnerable in the wild. It plays an important role in its ecosystem. These spiders live on the ground rather than in trees. They are found in the hilly, deciduous tropical forests of Mexico. This includes the western faces of the Sierra Madre Occidental and Sierra Madre del Sur mountain ranges. They live specifically in the states of Colima, Jalisco, and Michoacán.

To grow, this tarantula must undergo a process called molting. Because it is an arthropod, it possesses a hard exoskeleton. This outer shell cannot stretch as the animal grows. To increase in size, the spider must shed its old skin. Before molting, the spider becomes sluggish and stops eating. This helps it conserve energy for the difficult task ahead. The abdomen often darkens as the new exoskeleton forms underneath. The spider typically turns onto its back to molt. It wiggles its limbs to loosen the old shell. This process can take several hours. After molting, the spider may not eat for up to a month. This is because its fangs are part of the exoskeleton and remain soft until they harden.

For many years, scientists struggled to distinguish *B. hamorii* from a similar species called *B. smithi*. In 1897, *B. smithi* was first described, but the original specimens were later found to be immature males. In 1994, A. M. Smith redescribed *B. smithi* using two adult specimens. However, those specimens were actually *B. hamorii*. In 1997, Marc Tesmoingt, Frédéric Cleton, and Jean Verdez officially described *B. hamorii*. They noted differences in the female spermathecae, which are internal reproductive organs. The confusion persisted until 2017. That year, J. Mendoza and O. Francke clarified the distinction between the two species. They used DNA barcoding to prove they were unique. This method examines about 650 base pairs of the mitochondrial gene cytochrome oxidase I.

There are several physical ways to tell these spiders apart. When viewed from above, the chelicerae of *B. hamorii* often show two brownish-pink bands. *B. smithi* lacks these specific bands. In mature males, the palpal bulb is a key identifier. The palpal bulb of *B. hamorii* is narrower and less straight than the spoon-shaped bulb of *B. smithi*. In mature females, the shape of the spermathecae also differs. The baseplate of the *B. hamorii* spermatheca is elliptical. In contrast, the *B. smithi* version is divided and subtriangular. The ventral face of the *B. hamorii* spermatheca is also smooth rather than striated.

Physical dimensions and lifespans vary between the sexes. Adult females typically have a body length between 4.5 and 5.5 centimeters. Adult males are generally smaller in body length. However, males possess much longer legs than females. The fourth leg is the longest limb on the spider. The legs and palps are black or reddish-black. They feature three distinct colored rings. These include deep orange on the patellae and pale orange-yellow on the tibiae. The metatarsi end in a yellowish-white color. Longevity is also quite different for each sex. Females can live up to 30 years. Males usually live for only about 5 years.

In the wild, these spiders rely on complex burrows for survival.

They build or extend burrows under rocks, logs, or tree roots. These burrows protect them from predators like the white-nosed coati. A typical burrow has a single entrance and a tunnel. The tunnel is usually about three times the length of the spider's leg span. It leads to a chamber large enough for molting. A second, larger chamber is used for resting and eating. The entrance is only slightly larger than the spider's body. When the spider needs privacy to lay eggs or molt, it seals the entrance with silk, soil, and leaves.

Conservation efforts are vital for the survival of *B. hamorii*. The species faces threats from both the pet trade and local human activity. In 1985, *B. smithi* was placed on CITES Appendix II to regulate trade. Many Mexican redknee tarantulas are still smuggled out of the country. It was reported that at least 3,000 specimens were sent to the United States or Europe around 2017. Additionally, some local people kill the spiders due to myths and fear. They may use pesticides or gasoline in the burrows. While the species has been successfully bred in captivity, protecting their natural habitat remains a major challenge.