Ceratogyrus

Genus Ceratogyrus Pocock, 1897

Genus status. On systematic features is close to Pterinochilus.

Included genus Coelogenium Purcell, 1902 by R. Gallon in 2001.

Species C. meridionalis transfered by R. Gallon in 2001 from genus Pterinochilus. See also the tarantula synonymy section.

Type species – Ceratogyrus darlingi Pocock, 1897.

Genus Coelogenium Purcell, 1902 was established in 1902 by arachnologist Purcell on the single specimen of tarantula from Zimbabwe on feature of strongly procurved fovea. The type species, Coelogenium pillansi Purcell, 1902, was described on the base of a small, not mature female specimen. Some times later Ceratogyrus dolichocephalus Hewitt, 1919 there was described.

The genus was considered monotypical, while Smith in 1990 did not describe two new species: C. hyllyardi and C. raveni. One more species - C. nigrifemur was added by G. Schmidt in 1995. In 1990 А. Smith redescribe species Ceratogyrus dolichocephalus, note that the male, which was used for Hewitt's description, sooner belongs to Pterinochilus or any other species of Ceratogyrus.

De Wet and Dippenaar-Schoeman in 1991 have published revision of Ceratogyrus, described new species C. cornuatus and synonymyzed C. schultzei with C. bechuanicus, and in 1993 Charpentier proposed that genus Ceratogyrus is a junior synonym of the genus Pterinochilus. However А. Smith (1996) and N. Platnick (1997) have reject its suggestion and noticed that descriptions or type series of representatives of genuses were not examined.

In 2001 R. Gallon revised the genus Ceratogyrus, establishing a synonymy beside mentioned genera and its final status. However, in 2008 he publish the paper in which species C. bechuanicus and C. darlingi were synonymised.

The representatives of genus Ceratogyrus differs from other genus of african subfamily Harpactirinae with a combination of following features: the presence of scopula on undersite of chelicerae, consisting of feather-like stridulating hairs, and procurved fovea. Typically fovea strongly procurved and at several species has observable process ("horn").

This process can be denominated in form of continuation of caput, low tubercle or well denominated cone-shaped appendix. Its presence or absence as well as form and nature of location on carapace is distinctive systematic feature ( See Phil Messenger photo). Usually it begins to reveal after 4th molting (at C. brachycephalus can be noted already after second molt, at mature males of C. marshalli often will develop in the manner of small tubercle). There're several theories for its functionality exist, the most possible is considered to be a fat storage.

All species of genus Ceratogyrus have in front part of undersite of the abdomen transverse yellowish belt. This feature also is absent beside all other representatives of Harpactirinae, except species Augacephalus junodi Simon, 1904. There're radial grooves on carapace or they're absent. Undersite of pedipalps and legs I, II usually black colored. Tarsal leg's scopula not divided. Sternum with three pairs of oval sigilla. Spermathecae paired, fused at the base. Male palpal bulb is elongated, tibial spurs - at leg I.

The genus is presented by very unusual appearanced spiders of average and large size in majority having well denominated protuberance in the centre of carapace, after that they named "horned tarantulas", and also spicify coloration of body and carapace consisting of strips, maculaes and netlike drawing.

Several color morphs of some species are known: C. brachycephalus has 4 color forms - from gray to ligthbrown, C. bechuanicus - 3 forms as minimum (Lucian K. Ross, USA).

According to last revision of the genus (by R. Gallon the genus Ceratogyrus comprises 10 (ten) species.

Sizes of body are about 3-6 сm (males smaller - 2-3 сm), in legsspan can reach 15 см. Longevity supposedly about 8-10 years.

These unique tarantulas are very aggressive, mobile, have a painful bite, hereupon, a keeper must be very cautious keeping them.

They promptly attack the offender, and in case of their prosecution are actively protected.

In nature live in deep burrows. However several posts, the same as about representatives of genus Pterinochilus, noted their ability to made "arboreal retreat" (as the arboreal tarantulas did), which they placed in bases of overland nature covertures (C. meridionalis, C. behuanicus). The burrow inside is plentifully covered by a web and frequently an entrance is also too.

The majority of representatives of a genus have good appetite and quickly enough grow (young tarantulas frequently attack food objects bigger than their own size). Males became mature, as a rule, at 1.5-2 years, females at 2.5-3 (Gurley 1995). Eggsac consists of 120-150 eggs (175 eggs according the information from T. Ezendam 1997, (M. Jope, Baxter 1993). The shot period between II stage nymph and spiderling have noted (10-14 days), which comes in a nature by the beginning of a dry season (Hancock 1992).

Keeping conditions. In captivity, as against in a nature, as a rule, do not dig burrows, occupying given artificial shelters, occasionally digging out deepenings under pieces of cork bark etc., braiding a terrarium in and around the shelter with a thick web.

They must be kept at the lowered humidity (60%), on slightly humidified or nearly dry substratum, under temperatures 27-29°С with the water bowl for drinking. Thus, humidity for spiders of early ages should be higher, for what it is necessary to humidify a part of a substratum.

Terrarium for this species must be provided with good ventilation.

All species of genus Ceratogyrus can be kept under the similiar conditions. Can not be recommended for beginners.

Distribution. All Ceratogyrus spp. are submitted on the African continent (except for the north) occupying mainly xeric areas, including bushlands.
 

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