The Texas brown tarantula, or A. hentzi, is among the most common spider species living in Texas. When adults, they are dark brown and can reach a 4-inch leg span. The Texas tan tarantula, or A. anax, is among the spiders with longer lifespans; females can live up to 25 years, but males rarely live more than eight years. The Texas black spot, or A. armada, is very similar to the Texas brown, but it can show small black markings.
The Rio Grande gold tarantula, or A. moderatum, has a yellowish to golden back and a plain black ventral area, an exception among the genus Aphonopelma where most species are brown to black. Like most tarantulas, females of the Rio Grande gold are bigger than the males. The Rio Grande copper tarantula, or A. texense, is often light yellow and slightly smaller than the Rio Grande gold.
The identification of tarantula species within the genus Aphonopelma can be a difficult task for many people. The Texas species chocolate brown, or A. echinum; worth brown, or A. clarki; and Harlingen chocolate brown, or A. harlingenum, are similar in their name and appearance, with males and females showing light to dark brown bodies, as well as darker marks on their legs.
Some tarantulas living in Texas are less common and only identifiable through their scientific names, such as Aphonopelma breenei, Aphonopelma echinum,
Aphonopelma moderatum, Aphonopelma stahnkei, Aphonopelma cryptethum and Aphonopelma waconum. The differences between these species, as well as in other members of the genus Aphonopelma, are very subtle and sometimes down to genetic variations that are not easy to observe.