Bueana vitteli, Bauer, Christian & Prieto, Carlos E., 2009

Bauer, Christian & Prieto, Carlos E., 2009, Three new Assamiidae (Arachnida: Opiliones) from Cameroon, with a redescription of Chilon robustus and comments on related species, Zootaxa 2059, pp. 1-22 : 16-18

Bueana vitteli sp. nov.

Figs 5–6 , 22–28 , 52–55 , 70 , table 3

Types. 3 holotype (MRAC/148243), Kounden, river Mouh ( Cameroon), 5º42’N, 10º40’E (UTM: 32NPM83), F. Puylaert leg., 29.12.1975. Paratypes: 1 Ƥ with the holotype (MRAC/148243bis); 2 Ƥ (MRAC/148199), Kounden ( Cameroon), F. Puylaert leg., 28.12.1975; 1 3 (MRAC/148384), Kounden ( Cameroon), F. Puylaert leg., 28.12.1975; 1 Ƥ (MRAC/148204), Kounden, river Mouh ( Cameroon), F. Puylaert leg., 30.12.1975.

Etymology. The species is dedicated to David Bauer (“Vittel”), brother of the first author.

Diagnosis. A Bueana species characterized by having five segments in tarsus I, a row of spines on area V of the scutum and on the first free tergite, and a penis head with angulated lateral margins, and a crest on dorsal and ventral sides giving the penis the shape of a four ribbed sceptre.

Description. MALE (holotype): Total body length, 3.53; maximal width, 2.61 (at 2nd area of scutum). Scutum length, 3.32 (carapace/ scutum ratio, 0.43).

Coloration ( Figs 5–6 ). Light yellow ground colour, sometimes bright. Dorsal side: Patches of brown pigmentation laterally and posteriorly of ocularium interspersed by unpigmented spots; posterior region of carapace with a dark half-moon-shaped pigmentation on each side running from lateral posterior margin to lateral side of ocularium. Lateral margin of scutum with light brown pigmentation starting in the posterior half of carapace and reaching area II. Areas of scutum separated by unpigmented stripes; granules, tubercles and spines surrounded by unpigmented spots. Area I with brown pigmentation, medially and posteriorly lighter, and with an unpigmented posterolateral spot. Area II with two medially connected transversal brown stripes. Pigmentation of areas I–II not connected with marginal pigmentation. Areas III and IV with brown stripes and a small lateral field near the margin on each side; posterior zone with an unpigmented median spot. Area V and all free tergites with brown pigmentation, lighter at posterior margin. Anal operculum with brown margins and unpigmented centre. Ventral side: Coxa I–III uniformly yellow, coxa IV dorsally light brown and ventrally dark yellow. Free sternites brown; last free sternite with unpigmented posterior and anterior margins. Legs: Posterior margins of trochanter, femur, patella and tibia with light brown pigmentation; femur generally pigmented very light brown.

Carapace ( Figs 5 , 22, 24 ). Rather flat apart from a low medial elevation. Frontal tubercle system with outer lateral tubercles tilted upwards, inner lateral and central tubercles tilted downwards; outer lateral tubercles two times longer than central tubercle and two-thirds of the inner lateral tubercles. Anterior margin of carapace with a robust median tubercle and a row of small granules on each side. Ocularium situated in anterior half of prosoma, its profile low, elliptical, occupying one-third of width and one-fourth of length of carapace, with a pair of granules anterior and a pair of tubercles posterior to transversal eye-line. Lateral margin of carapace obtusely angled at eye-line level and diverging towards posterior margin, with a short row of granules running along posterior half. Posterior margin of carapace broadly V-shaped, thus narrowing area I of scutum, and apparently strongly sclerotized.

Opisthosomal part of scutum ( Figs 5 , 22, 24 ). Rather flat, except for a gentle median elevation, reaching maximum width at line between areas II and III; posterior margin at right angles to parallel posterior-lateral margins. Areas lightly separated by mediolateral depressions. Area I much narrowed medially, with a pair of small paramedian tubercles separated by a pair of granules. Area II with a pair of larger paramedian tubercles flanked by a pair of granules. Area III with a pair of paramedian spines separated by a pair of granules anteriorly. Area IV with a pair of small paramedian tubercles. Area V with a median spine, as long as those in area III, two large tubercles and some decreasing tubercles/granules in a laterally anteriorwards curved row on each side; corners unarmed. Lateral margin with some granules in areas III–IV.

Free tergites ( Figs 22, 24–25 ). Free tergite I with a median spine and a row of 2–3 tubercles with intercalate granules on each side. Free tergite II with a pair of paramedian spines, two granules between those spines, and with a small denticle and a shorter lateral spine on each side. Free tergite III with a median spine, one or two granules and a lateral spine on each side; lateral corners, frequently covered by free tergite II, bearing a small tubercle. Anal operculum with two rows of tubercles, three anteriorly and 1–3 posteriorly.

Venter ( Figs 6 , 23, 25 ). Surface of prosomal complex irregularly covered by small granules. Coxa I crested by a row of 5–7 tubercles on anterior margin, with innermost tubercle clearly on ventral surface and larger than others, and two tubercle rows on the ventral surface. Both rows rising from a tubercle tuft near median corner of coxa and ending on opposite distal corners; anterior row ending with three tubercles along fronto-distal margin, while posterior row, running along posterior margin, with more and smaller tubercles. No granules between both rows, only a tubercle (sometimes two) between distal ends. Coxa II with larger granules along inner half of anterior margin and on prolateral corner. Coxa III with increasingly large tubercles along both anterior and posterior distal margins; apical parts of tubercles seemingly fused with cuticula of adjacent coxa. Coxae I–II bearing prominent tubercles on prodorsal and retrodorsal margins, coxa III on prodorsal margin only; retrodorsal tubercle of coxa II seemingly fused with opposite prodorsal tubercle of coxa III (tubercles between coxae I and II are close only). Coxa III with a row of seven tubercles below scutal margin. Coxa IV with few tubercles on dorsal and prolateral surfaces transforming ventrally into granules covering whole coxosternal complex. Genital operculum rounded anteriorly and flattened posteriorly; granular. Spiracular grooves laterally covered by papilliform tubercles arising from lateral margin of coxosternal complex and from retrolateral surface of coxa IV. Posterior margin of coxosternal complex with a row of granules. Sternites IV–VII with rows of sparse granules. Sternal-anal plate (sternites VIII/IX) large and conspicuously bent in lateral view ( Fig. 24 ), with some granules along posterior margin.

Chelicerae ( Fig. 26 ). Basal segment with a granular bulla bearing some small tubercles on mesal and posterior surfaces. Second segment distinctly granular, with setae on dorsal surface.

Pedipalps ( Figs 27–28 ). Coxa with 1–2 small distodorsal denticles. Trochanter dorsally with some granules and ventrally with a large denticle; ectal side with a small tubercle and a granule. Femur ventrally with a row of 7–9 denticles decreasing in size along first two thirds of length; dorsal and ectal surfaces granular. Patella with a mesoapical denticle. Tibia with IiiIi on mesal and iiiIi on ectal edges. Tarsus with iiiIiI on mesal and iiIiI on ectal edges. Dorsal surface of patela, tibia and tarsus granular and with sparse setation.

Legs ( Table 3 ). Granular. Calcaneus I 17 % of metatarsus length. Tarsal formula 5(2) / 10–13(4) / 7 / 8–9.

Penis ( Figs 52–55 ). Total length, 2.05. Stalk tall and cylindrical, with a four-ribbed head, giving the penis the shape of a sceptre. Head of penis broad at base, with a spinulate apical bulge on each side, giving it a quadratic outline with concave distal and lateral sides in ventral view. Ventral and dorsal surfaces with a rounded median keel, dorsal keel larger and wider than ventral one. Glans long, siphon-like, inserting near concave distal margin. Apical bulges convex and conspicuously delimited in lateral view, each with six large foliate setae pointing proximad and four apical setulae pointing distad; two of the foliate setae situated ventrally, three laterally and one dorsally, setulae situated distally.

FEMALE (MRAC/148243bis): Total body length, 3.6; maximal width, 2.5 (at 2nd area of scutum). Scutum length, 3.22 (carapace/scutum ratio, 0.39). Body and appendages as in male, but with thicker femora and patellae. Measurements of pedipalp and legs, see table 3.

Ovipositor ( Fig. 70 ). Bilobed, inner surface concave. Apical edge and surface of lobes finely dentate, with five setae on outer margin, two of them situated ventrally and three dorsally; blunt setal tips with subapical ramus.

Remarks. The African stock of the subfamily Polycoryphinae comprises thirteen monotypical genera: Maracandinus Roewer, 1912 and Gulufia Roewer, 1935 from Ethiopia; Procoryphus Roewer, 1950 , Pulchandrus Kauri, 1985 and Uviranus Kauri, 1985 from eastern Congo; Parakodaika Goodnight & Goodnight, 1944 and Polycoryphus Loman, 1902 from Namibia and Angola; Thomecola Roewer, 1927 , Santhomea Roewer, 1927 , Palmanella Roewer, 1927 and Henriquea Roewer, 1927 from Sao Tomé and Prince islands; and finally, Binderella Roewer, 1935 and Bueana Roewer, 1927 from Cameroon.

Roewer’s (1935) system is based on tarsal formula and dorsal armature, and the new species, with paramedian pairs of spines in areas I–III and an unarmed fourth area, most closely resembles species in the Cameroonian genera. Penial morphology is known only for Pulchandrus longimanus Kauri, 1985 and Uviranus echinops Kauri, 1985 , and provides no help for the taxonomic placement of the new species. A close relationship with Binderella is excluded because Binderella only has a median spine on the third free tergite which, due to extreme sexual dimorphism, takes the shape of a long stiletto in females (described as Tengelinia paradoxa Roewer, 1935 ), while Bueana has a uniform armature on its free tergites and lacks any conspicuous sexual dimorphism.

Bueana ephippiata Roewer, 1927 differs from Bueana vitteli sp. nov. in the unarmed fifth area of the scutum and the unarmed first free tergite, which in Bueana vitteli sp. nov. carries a row of tubercles (reaching the size of spines in the centre), and in the number of segments in tarsus I (six rather than five).

Figures

FIGURES 1 – 8. Dorsal (left) and ventral (right) views of males. 1 – 2, Chilon robustus Sørensen, 1896. 3 – 4, Ereca treses sp. nov. 5 – 6, Bueana vitteli sp. nov. 7 – 8. Rhabdopygus puylaerti sp. nov.

FIGURES 22 – 28. External morphology of Bueana vitteli sp. nov. (male holotype). 22, body, dorsal view. 23, body, ventral view. 24, body, lateral view. 25, body, posterior view. 26, right chelicera, ectal view. 27, right pedipalp, mesal view. 28, trochanter and coxa of pedipalp. Scale bars: 1 mm.

FIGURES 48 – 55. Ereca treses sp. nov. and Bueana vitteli sp. nov., penis head in ventral (48, 52), lateral (49, 53) and dorsal view (50, 54), and total penis in dorsal view (51, 55). 48 – 51, Ereca treses sp. nov. (paratype from Mt Eloumden). 52 – 55. Bueana vitteli sp. nov. (paratype from Kounden, MRAC / 148384). Scale bars: Left 0.1 mm, right 1 mm.

FIGURES 68 – 70. Ovipositors (with detail of their hair tips). 68. Chilon robustus Sørensen, 1896. 69. Ereca treses sp.

Tables

TABLE 3. Measurements of pedipalp and legs of male holotype / female paratype (MRAC / 148243) of Bueana vitteli sp. nov.

	Trochanter	Femur	Patella	Tibia	Metatarsus	Tarsus	Total
Pedipalp Leg I	0.5 / 0.4 0.45 / 0.45	1.3 / 1.2 1.5 / 1.55	0.8 / 0.8 0.7 / 0.7	0.75 / 0.75 1.8 / 1.75	– 1.95 / 2.0	0.8 / 0.8 1.2 / 1.15	4.15 / 3.95 7.6 / 7.6
Leg II	0.5 / 0.5	3.8 / 3.4	1.0 / 0.8	2.9 / 2.85	3.5 / 3.4	2.65 / –	14.35 / –
Leg III Leg IV	0.55 / 0.55 0.6 / 0.5	2.75 / 2.6 4.0 / 3.6	0.95 / 0.85 0.95 / 0.9	1.85 / 1.7 2.7 / 2.35	2.65 / 2.5 4.1 / 3.85	1.55 / 1.4 1.65 / 1.75	9.3 / 8.6 14.0 / 13.0