Brachypelma smithi vs hamorii – A River Divides Them #animalfacts #shorts #brachypelma

Added: 2026-06-02

[00:00:00]Meet the real Brachypelma smithi. For years, it's been confused with its twin, Brachypelma hamorii. If you saw a Mexican red knee in a pet store before 2017, it was probably a hamorii.

[00:00:16]Here is the actual B. smithi living south of the Balsas River in Guerrero.

[00:00:22]That means its range is separated by the Balsas River from the almost identically looking species. On the other side of that river, that's where hamorii lives.

[00:00:34]Nature built a river wall between them.

[00:00:38]Brachypelma smithi is a large spider.

[00:00:42]Females are tanks, 52 to 59 mm, 2.0 to 2.3 in. Males are slightly shorter in body, 44 to 49 mm, 1.7 to 1.9 in, but they have longer legs.

[00:01:01]Look at the male's yellowish-brown carapace. Females keep that dark starburst pattern or bluish-black with a light brown border.

[00:01:12]Notice the legs, bluish-black with three distinct rings. Adult females vary more in carapace color and pattern. Sometimes a starburst, sometimes almost two dark patches near the eyes.

[00:01:28]They live in the deciduous forests of Guerrero, south of the Balsas Basin. And they are architects. They construct or extend deep burrows under rocks and tree roots among dense thickets.

[00:01:43]Why so deep? To hide from predators like the white-nosed coati.

[00:01:49]Females spend most of their lives inside. The entrance is just slightly larger than their body. The tunnel, about three times the tarantula's leg span, leads to a chamber for safe molting.

[00:02:04]Further down, a larger chamber for resting and eating.

[00:02:09]When the tarantula needs privacy, molting, or laying eggs, it seals the entrance with silk, sometimes reinforced with soil and leaves.

[00:02:20]So, is your red knee a true Brachypelma smithi?

[00:02:24]Check the map.

[00:02:26]If it didn't cross the Balsas River from Guerrero, it's probably a hamorii.