Ogovea cameroonensis, Giribet, Gonzalo & Prieto, Carlos E., 2003

Giribet, Gonzalo & Prieto, Carlos E., 2003, A new Afrotropical Ogovea (Opiliones, Cyphophthalmi) from Cameroon, with a discussion on the taxonomic characters in the family Ogoveidae, Zootaxa 329, pp. 1-18 : 4-12

Ogovea cameroonensis new species

Figs. 1–32

Type specimens. Male holotype from the forêt d’Ototomo, Région de Yaoundé ( Cameroon), collected 16 December 1968 by J.­L. Amiet, deposited at MHNG. One male and three female paratypes, same collection data as holotype, deposited at MHNG. One male and one female paratypes, same collection data as holotype, deposited at MCZ (material used for SEM). Two female paratypes, collected 5 February 1967 by J.­L. Amiet, same locality as holotype, deposited at MHNG. Three male and two female paratypes, collected 4–6 April 1969 by J.­L. Amiet, same locality as holotype, deposited at MHNG. One female paratype, collected 17 May 1969 by J.­L. Amiet, same locality as holotype (with coordinates specified as 3º 40’ N, 11º 18’ E and altitude specified as 700–800 m), deposited at MHNG. One female paratype, collected 30–31 December 1968 by J.­L. Amiet, same locality as holotype, deposited at MHNG. One male (penis studied from this specimen) and one female paratypes, collected by J.­L. Amiet in Yaoundé, deposited at MRAC 134.818.

3. The type material of O. nasuta is supposed to be deposited at MCSN. Despite several letters and e­mails to the curators and administrators of the MCSN, no response has been obtained. Fortunately, a male specimen,

supposedly of the type series, was somehow transferred to the ZMUC, making possible the study of this species. 4. Shear (1979) mentioned that one male and one juvenile paratypes were deposited at the MCZ accompany­

ing the holotype, however, the tube labeled as “ paratypes ” contains three males and one juvenile.

5. We have not been able to locate the supplement of volume 24 of The Entomologist with the description of

Ogovia Holland, 1892

Other material. Male collected 5 February 1967 by J.­L. Amiet, same locality as holotype, deposited at MHNG.

Etymology. The species is named after its country of origin.

Diagnosis. This species is the largest in the genus, reaching up to 5 mm in body length. The tricuspidate process of the anterior margin of the scutum is short, with its middle cusp shorter than the lateral ones. The tricuspidate process interlocks with the dorsal crest of the chelicerae; such crest is more conspicuous than in other species of the genus.

Description. Total length of male holotype ( Figs. 1–4 ) (female paratype in parenthesis) 5.0 (5.0), greatest width 2.6 (2.8) at the merging of prosoma and opisthosoma; lengthwidth ratio 1.92 (1.79). Body orange (in alcohol) with most of the dorsal and ventral surfaces and legs showing a dense tuberculate­granulate microstructure (nomenclature on ornamentation follows Murphree 1988). Anterior margin of dorsal scutum forming a tricuspidate process (“processus triangulaire prolongeant” of Juberthie 1969), but the median “cusp” (the actual process) barely reaches the other two cusps, allowing the basal cheliceral article to extend horizontally ( Fig. 7 ). Prosomal region short. Eyes absent. Ozophores conical, raised from the carapace margin, with the aperture resembling closed lips ( Fig. 6 ). Transverse prosomal sulcus conspicuous ( Figs. 1 , 3 ). Transverse opisthosomal sulci equally conspicuous ( Figs. 1 , 3 ). Mid­dorsal longitudinal opisthosomal sulcus conspicuous, starting towards the end of tergite I until tergite VIII; tergite IX lacking the mid­dorsal longitudinal sulcus ( Figs. 1 , 3 ). Dorsal scutum without special modifications.

Coxae of leg I movable, coxae of the remaining legs fused. Ventral prosomal complex of male with coxae II and IV meeting in the midline, and coxae III barely touching each other ( Figs. 4–5 ). Gonostome in the shape of a flattened oval, much wider than long ( Fig. 5 ). Ventral prosomal complex of females with coxae II, III, and IV not meeting in the midline, and coxae I forming the anterior wall of the gonostome.

Spiracles small and forming a circle completely closed ( Fig. 8 ). A large, broad, oblong, subacute process directed downwards and backwards projects behind the gonostome, in the sternal region of the second opisthosomal segment of the male ( Figs. 2 , 4 , 5 , 10–12 ) (see Hansen 1921; Shear 1980). The process bears numerous long setae ( Figs. 10– 12 ). The sternal region of segments 2–4 forms a concave depression free of granulation underneath the sternal apophysis, with sternite 5 becoming somehow convex ( Fig. 5 ). A special structure in the shape of a half moon is present at the base of the apophysis, and is observed at both sides ( Figs. 11–13 ). Sternites 8 and 9 and tergite IX completely fused forming a corona analis ( Fig. 9 ). Anal plate without modifications; anal gland pore absent; sexual dimorphism not present ( Fig. 9 ).

Chelicerae ( Fig. 16 ) relatively short and strong, with numerous long setae, especially on the second article. Proximal article with ectal surface granulated, a conspicuous dorsal crest, and an inconspicuous ventral process. The dorsal crest collides with the internal surface of the elongated anterior prosomal process, not allowing the extension of the chelicerae forward. Second article fairly robust, lacking granulation. Dentition uniform and similar on both cheliceral fingers. Granulation of the chelicera of special type ( Fig. 17 ) with short denticle­like setae. Chelicerae lacking Hansen’s organ.

Palps ( Figs. 18–20 ) similar to those of Ogovea grossa illustrated by Juberthie (1969: Fig. 9 ), with a trochanter that thins considerably at the base and widens in the trochanterofemoral joint; without a ventral process ( Fig. 18 ). Femur compressed laterally, suboval in shape ( Fig. 19 ), and folded slightly over the chelicera, so that the tibiae of both palps enclose the chelicerae ( Fig. 7 ).

Legs short and robust ( Figs. 21, 23, 24, 27 ); with all claws smooth, long and hook­like, without dentition or lateral pegs. Surface of all articles, including the base and the dorsal surface of tarsi I and II, clearly and completely ornamented with granules ( Figs. 22, 25, 28 ). Ventral side of tarsus I with a concentration of short sensory hairs occupying about half of the tarsal length and forming a distinct solea ( Fig. 22 ). All tarsi with a large dorsal groove for retracting the claws. Patella, tibia, metatarsus and tarsus of leg III with a longitudinal seam in the ectal side ( Figs. 24–26 ). Tarsus IV of male entire ( Fig. 28 ), carrying a short thornlike adenostyle that ends abruptly at the beginning of the tarsal groove, past the tarsal half; the adenostyle not ending in a tuft of setae or any bushy formations ( Fig. 29 ). Tarsus IV of females without modifications.

Penis with numerous setae that make the correct interpretation of all the structures difficult. Ventral plate hypertrophied ( Figs. 30–32 ) with 4–5 rows of short setae ( Figs. 31–32 ) in the most distal part of the dorsal side. Ventral setae in a single series. Median plate sclerotized and with 4 apical setae ( Figs. 31–32 ). Membranous structure around gonopore. Dorsal setae long, forming two groups.

Cuticular structures. The Hansen’s organ ( Figs. 15 , 28 ) is found in the surface of all four coxae and legs. On coxae I, II, and III it is found near the socket where the trochanter’s condyle inserts; on coxae IV there is one organ in a similar position, but a much larger one (splitting in two in some cases) occurs near the gonostome opening. Concentrations of these structures occur in most articles of the leg, e.g. up to three per article on tarsus IV.

Distribution. Known only from the type locality.

Remarks. This species is most similar to Ogovea grossa from Gabon, but the new species is much larger, and both species can be differentiated by the anterior process, which appears tricuspidate from above, but the median “cusp” (the actual process) barely reaches the other two cusps in O. cameroonensis , while in O. grossa it is clearly more developed. The chelicerae of O. cameroonensis are longer than those of O. nasuta , and about the same proportional shape than those of O. grossa , but they differ in the dorsal crest, which is much more conspicuous in O. cameroonensis .

A small male, measuring 3.9 mm, was collected from the type locality. The specimen resembles O. cameroonensis in salient morphological features and was collected together with two of the female paratypes. The male specimen has a teratologic right leg IV where the tarsus and tibia are not properly developed and the tarsus lacks an adenostyle. We are uncertain about whether the specimen belongs to a similar species of smaller proportions.

Figures

FIGURES 1 – 2. Holotype of Ogovea cameroonensis sp. n. 1. Dorsal view; 2. Ventral view.

FIGURES 3 – 4. Holotype of Ogovea cameroonensis sp. n. 3. Dorsal view; 4. Ventral view. Scale bar 1 mm.

FIGURES 5 – 9. Paratypes of Ogovea cameroonensis sp. n. 5. Male, ventral view; 6. Ozophore; 7. Female, dorsolateral view of the anterior prosomal region; 8. Spiracle, ventral view. 9. Anal region of male, ventral view.

FIGURES 10 – 15. Paratypes of Ogovea cameroonensis sp. n. 10. Sternal apophysis of male, ventral view; 11. Detail of the opisthosomal sternal organ (oso) underneath the sternal apophysis of male, posterior view. 12. Detail of the male sternal region with the opisthosomal sternal organ (oso), ventral view; 13. Detail of the glandular pores of the male opisthosomal sternal organ, ventral view; 14. Detail of the cuticular ornamentation of the sternal apophysis of male, ventral view; 15. Hansen’s organ (H) and cuticular hairs, ventral view.

FIGURES 16 – 20. Anterior appendages of male paratype of Ogovea cameroonensis sp. n., ectal view. 16. Left chelicera; 17. Detail of the ornamentation of the chelicera; 18. Left palp; 19. Femur of left palp; 20. Palpal claw.

FIGURES 21 – 29. Legs of male paratype of Ogovea cameroonensis sp. n. 21. Leg I, ectal view; 22. Tarsus I, ectal view; 23. Leg II, ectal view; 24. Leg III, ectal view showing the longitudinal seam (arrowheads); 25. Tarsus III, ectal view showing the longitudinal seam (arrowheads); 26. Tibia III, ectal view showing the longitudinal seam (arrowhead); 27. Leg IV, mesal view; 28. Tarsus IV, mesal view; 29. Detail of the adenostyle, mesal view.

FIGURES 30 – 32. Ogovea cameroonensis sp. n, dorsal view. 30. total penis (vp indicates ventral plate). 31 – 32. Gonopore complex and series of dorsal setae. Scale bar 0.5 mm.