''Hemirrhagus akheronteus'' is a

tarantula Tarantulas comprise a group of large and often hairy spiders of the family Theraphosidae. , 1,040 species have been identified, with 156 genera. The term "tarantula" is usually used to describe members of the family Theraphosidae, although ...

which is part of the ''

Hemirrhagus ''Hemirrhagus'' is a genus of Mexican tarantulas that was first described by Eugène Louis Simon in 1903. It is considered a senior synonym of ''Spelopelma''. Species of the genus ''Hemirrhagus'' are 5 to 12 cm long, usually black in colour, the ...

'' genus. It is found in

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

, in the state of Queretaro, and is one of many Mexican cave tarantulas. It was first described by Mendoza and Francke in 2018. It is named after the latin word akheronteus, which means "pertaining to the stream of woe", referring to the

acheron The Acheron (; grc, Ἀχέρων ''Acheron'' or Ἀχερούσιος ''Acherousios''; ell, Αχέροντας ''Acherontas'') is a river located in the Epirus region of northwest Greece. It is long, and its drainage area is . Its source is ...

river in the infernal regions of

Greek mythology A major branch of classical mythology, Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the Cosmogony, origin and Cosmology#Metaphysical co ...

Characteristics

The tarantula's color is a solid grey or even black, making it blend in well with rocks. This tarantula, although being from

the New World The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. 3 ...

, lacks

urticating hairs Urticating hairs or urticating bristles are one of the primary defense mechanisms used by numerous plants, almost all New World tarantulas, and various lepidopteran caterpillars. ''Urtica'' is Latin for "nettle" (stinging nettles are in the genus ...

. Males have thorn like hairs on their legs, which are attached to a socket and are mobile. Females lack these hairs. The specimens of this investigation were captured 400m from the cave entrance.

Habitat

They are found in the cave in the state of Queretaro in the

Jalpan de Serra Jalpan de Serra () is a town in Jalpan de Serra Municipality located in the north of the state of Querétaro, Mexico. It is located in the heart of an important ecological zone called the Sierra Gorda. It is also the site two of five Franciscan ...

town, inside the cave "Cueva del Río Jalpan". This cave is found in the middle of the

Sierra Gorda The Sierra Gorda () is an ecological region centered on the northern third of the Mexican state of Querétaro and extending into the neighboring states of Guanajuato, Hidalgo and San Luis Potosí. Within Querétaro, the ecosystem extends from ...

natural reserve A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, or features of geological or o ...

. In the reserve there is mostly

cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

rocks, with

sedimentary Sedimentary rocks are types of rock (geology), rock that are formed by the accumulation or deposition of mineral or organic matter, organic particles at Earth#Surface, Earth's surface, followed by cementation (geology), cementation. Sedimentati ...

and conglomerates rocks. The reserve is from 300m to 3,100m

above sea level Height above mean sea level is a measure of the vertical distance (height, elevation or altitude) of a location in reference to a historic mean sea level taken as a vertical datum. In geodesy, it is formalized as ''orthometric heights''. The comb ...

, most of it being between 1,300m and 2,400m. The reserve has semi warm to sub humid climates.

References

Theraphosidae Endemic spiders of Mexico Spiders described in 2018 Cave spiders Fauna of the Sierra Madre Oriental {{Theraphosidae-stub