The species formerly placed in Haplopelma are medium to large spiders; for example, Cyriopagopus schmidti females have a total body length, including chelicerae, up to, with the longest leg, the first, being about long. The carapace is generally dark brown. They have eight eyes grouped on a distinctly raised portion of the cephalothorax, forming a "tubercle". The forward-facing sides of the maxillae have "thorns", which act as a stridulating organ. The first leg is usually the longest, followed by the fourth, second, and third. Mature females have an M-shaped spermatheca. Mature males have a spur on the forward-facing sides of the tibiae of the first pair of legs and a pear-shaped palpal bulb with a wide, curved embolus.
Taxonomy
The nomenclature of a group of theraphosid genera from South and Southeast Asia, including Cyriopagopus, Haplopelma, Lampropelma, Omothymus, and Phormingochilus, is somewhat confused. The status of the genera has changed several times recently, and species have been moved from one genus to another. Currently, Haplopelma is considered to be a junior synonym of Cyriopagopus, and Melopoeus of Haplopelma, hence of Cyriopagopus, but this may change. The genus Cyriopagopus was erected by Eugène Simon in 1887 for the species Cyriopagopus paganus from Burma. In 1985, Robert Raven made Cyriopagopus the senior synonym of Melognathus Chamberlin, 1917. In 1890, Tamerlan Thorell described a species of spider under the name Selenocosmia doriae. In 1892, Eugène Simon decided that this species was sufficiently different from others placed in the genus Selenocosmia to warrant a new genus, Haplopelma, with one species, Haplopelma doriae. Raven in 1985 also decided that Haplopelma was the senior synonym of Melopoeus Pocock, 1895. A. M. Smith studied the type specimen of Cyriopagopus paganus and decided that it had the key characteristics of Haplopelma, making Cyriopagopus the senior synonym of Haplopelma. This analysis is accepted by the World Spider Catalog as of 2017, with the comment that "Haplopelma, Cyriopagopus, Melopoeus, and other ornithoctonine genera are in urgent need of revision".
Distribution and habitat
The genus is found in Southeast Asia, Borneo, and the Philippines. Species that have been studied live in underground, silk-lined tubes, often with a surrounding web of radiating signal threads. They may be found in small colonies at the base of trees or bamboos. Some species favour steep, south-facing slopes.
Toxicity
Like all Old World tarantulas, spiders in the genus Cyriopagopus lack the urticating hairs found in their New World counterparts, hence use biting as a primary means of both attack and defence. Some Cyriopagopus species are among those reported to have more toxic venom. Although bites may cause severe pain and a range of other effects, no fatalities are known. Cyriopagopus lividus, C. hainanus, and C. schmidti have had their venom characterized. The last two produce hainantoxins and huwentoxins, respectively. Additionally, as with any envenomation, there is the possibility of a potentially life-threatening allergic reaction and the large fangs can produce puncture wounds which are susceptible to bacterial infection if not treated properly.
