Machadocepheus rachii, Fernandez, Nestor, Theron, Pieter, Rollard, Christine & Leiva, Sergio, 2014

Fernandez, Nestor, Theron, Pieter, Rollard, Christine & Leiva, Sergio, 2014, The family Carabodidae (Acari, Oribatida) VIII. The genus Machadocepheus (first part) Machadocepheusleoneae sp. n. and Machadocepheusrachii sp. n. from Gabon, ZooKeys 456, pp. 1-28 : 8-16

Taxon classification Animalia Oribatida Carabodidae

Machadocepheus rachii sp. n. Figures 38-72

Etymology.

The specific epithet is dedicated in homage to Mr Rachid Kebir of Muséum National d’Histoire Naturelles, Paris, who assisted us with great kindness and friendship on many occasions over the past 20 years.

Material examined.

Holotype and four Paratype females. Makokou, northeastern province of Ogoové-Ivindo, 500 m. alt.dense evergreen humid forest, I.1974, Y. Coineau, deposited in MNHN. Paratypes. Same data as holotype, 4 ♀ (2 in MNHN; 2 in MNHG). All specimens preserved in 70% ethanol. Type locality. Makokou, province of Ogoové-Ivindo, northeastern Gabon; situated at 0°34'0"N, 12°52'0"E. Material used for SEM observations not deposited.

Diagnosis adult female.

Thin cerotegumental layer covering entire body, giving the impression of a smooth surface. Setae ro, in, notogastral, sub-capitular, epimeral, genital, aggenital, adanal, anal, simple sharply tipped; le lanceolate, barbate.

Polyhedral prodorsum; interlamellar process elevated, divided sagittally by large deep furrow; in setae situated anteriorly, directing posteriorly. Conspicuous deep posterior prodorsal depression present. Bothridium cup-shaped; bothridial ring and bothridial tooth present. Sensillus uncinate, upturned; le setae situated ventrally on apical zone of lamellae. Lamellae running dorsolaterally, lacking lamellar tip; large, deep, shallow lamellar furrow demarcating paraxial lamellar margin. Superior cornea of naso clearly visible as convex elevation situated anterior to insertion level of ro setae.

Anterior part of notogaster rectangular; posterior part oval with some irregularities and less conspicuous promontories, dorsosejugal furrow narrow, rectilinear, hardly discernible. Fifteen pairs of notogastral setae (holotrichy unideficient), c1, c2, c3, da, dm, dp, la, lm, lp, h1, h2, h3, p1, p2, p3. Notogaster presenting: notogastral anterior depression; elevated zone; slightly concave posterior depression. Notogastral anterior depression simple, with transversally aligned parallel cuticular folds. Elevated zone with three pairs of poorly developed promontories that bear da, dm, dp setae; and lateral semicircular, poorly developed promontories, that bear la, lm, lp, h1, h2 setae. Humeral apophysis long, clearly visible.

Tutorium: rod-like curving cuticular thickening; supratutorial depression present; along with three pocket-shaped depressions, one anterior tutorial depression, one posterior tutorial depression and a small depression situated internally to supratutorial depression. Pedotecta I, prominent extended lamina, rounded apex; Pedotecta II small, ovoid lamina. Lyrifissures ih, ips clearly visible. Discidium: polyhedral structure with rounded apex. Depressions behind acetabulum IV; one of them elongated, concealing tarsus during folding legs process. Series of aligned depressions in medial zone. Epimeral chaetotaxy 3 –1-3– 3; anterior genital furrow clearly visible; four pairs of long genital setae; two pairs of small anal setae; anal fig terminating in small sharp tip; aggenital and adanal setae similar length; lyrifissures iad not discernible.

Description.

Measurements. Light microscopy: 421 μm (396-426) × 262 μm (238-268) (on six specimens). SEM microscopy: 416 μm (398-416) × 176 μm (173-181) (on six specimens, not deposited).

Shape. Ovoid (Figures 38, 41).

Colour. Specimens without cerotegument, light to dark brown, when observed in reflected light.

Cerotegument. Thin layer 1.5 μm (1.3-2.5) covering the entire body and legs (Figures 38, 41, 42, 44, 47, 48, 49 indicated by , 52, 53, 56, 57, 58, 59, 63), permitting observation of only large cuticular microsculptures (Figures 44, 46, 48, 53, 58, 59, 62), giving the impression of a smooth surface. Complete removal was necessary for optical microscopy, once removed, detailed microsculpture became visible (Figure 63).

Integument. Two sizes of ornamentations: Small 1.2-3.5 μm, 1) small ovoid to irregular protuberances, distributed throughout prodorsum and notogaster (except notogastral zone near s.c) (Figure 49) 2) irregular elongate protuberances, notogastral zone near s.c (Figures 41, 58, 61 indicated by ). Large 7.2-7.9 μm, two types: 1) simple rounded fovea (Figure 63), situated on posterior part of elevated zone of notogaster (Figures 41, 58, 59, 62 indicated by ); 2) polyhedral fovea (distributed side by side), situated on prodorsum (e.i.p, lamellae, near ro insertion, bothridium), notogaster (elevated zone, lateral zone) (Figures 41, 42, 48, indicated by ).

Setation. Setae ro, in, notogastral, subcapitular, epimeral, genital, aggenital, adanal, anal: simple, sharply tipped (Figure 60) (Figures 38, 39, 40, 42, 44, 48, 52, 53, 57, 58, 59, 62, 51); le lanceolate, barbate (Figures 44, 55, 56).

Prodorsum. Polyhedral (dorsal view) (Figures 38, 41); triangular (lateral view) with strong obliquely decreasing anterior part (Figures 40, 46, 47). Interlamellar process (e.i.p) elevated (Figures 40, 46, 47), divided sagittally into two promontories by large deep furrow (Figures 41, 42, 47, 58 indicated by ), in setae situated anteriorly and directing posteriorly (Figures 42). Conspicuously depressed posterior prodorsal zone (p.p.d) (Figures 38, 41, 47, 58). Three pairs of setae; sizes in> le> ro. Ro setae clearly visible in frontal view (Figures 42, 44), situated in medial zone, inserted posterior to insertion level of le; rounded structure between ro setae, probably vestigial superior cornea of naso cso (Figures 42, 44); bo cup-shaped, bo.ri smooth; bothdial tooth present (Figures 46, 51). Si uncinate, upturned (Figures 46, 51); le setae situated ventrally on apical zone of lamellae (Figures 42, 44, 56).

Rostral margin slightly rectangular to hexagonal (Figures 42, 44). Lamellae running dorso laterally, lacking lamellar tip (Figures 42, 44, 56); large deep furrow (l.l.f) demarcating inner paraxial margin of lamellae (Figures 41, 42, 47). In frontal view (Figure 42), l.l.f showing a deeper medial zone. The superior cornea of naso (cso) clearly visible as convex elevation situated anterior to ro setal insertion level (Figures 42, 44).

Notogaster. Shape: dorsal view, anterior part rectangular and posterior part oval (Figures 38, 41, 58); in lateral view, anterior part rectilinear, with clearly concave medial zone and rectilinear exteriorly, rest triangular to polyhedral with some irregularities and unremarkable promontories (Figures 40, 46, 47, 48, 53); d.sj narrow, rectilinear, hardly discernible (Figures 41, 47); notogastral anterior depression (n.a.d), ovoid and conspicuous.

Fifteen pairs (holotrichy unideficient) of notogastral setae: c1, c2, c3, da, dm, dp, la, lm, lp, h1, h2, h3, p1, p2, p3.

Notogaster presenting: 1) n.a.d occupying anterior notogastral zone; 2) elevated zone situated in posterior third of notogaster; 3) slightly concave n.p.d situated posterior to elevated zone (Figures 41, 46, 47, 48); 4) slightly inclined more or less flat zone situated behind s.c, with irregularly elongated protuberances (Figures 41, 58, 61 indicated by ); circumgastric depression (s.c) hardly discernible (Figures 53, 58, 61).

Simple n.a.d (Figures 38, 41, 47) with many hardly discernible transversally aligned parallel cuticular folds situated posterior to d.sj (Figures 47, 58, 59, 62 indicated by ). Elevated zone presenting series of aligned flat medial promontories (three pairs, poorly developed) bearing setae da, dm, dp and lateral poorly developed semicircular promontories, bearing setae la, lm, lp, h1, h2.

Humeral apophysis (h.ap) very long, clearly visible (Figures 38, 41) but best observed in lateral view (Figures 46, 47).

Lateral region (Figures 40, 46, 47, 48). Palp clearly discernible (Figure 50), sul ζ (ul ζ), acm ζ; solenidium ω very long, extending to level of eupathidia. Cheliceral setae chb clearly visible (Figure 50).

Lamellae (lam) easily discernible, large, lacking sharp la.ti, with elevated zone at le insertion level (Figure 40, 46, 47, 56).

Tutorium (tu): rod-like curving ridge; s.tu.d a deep depression running between lamellae and tutorium; pocket depressions a.tu.d, p.tu.d present; another small depression situated internally to s.tu.d (Figure 40 indicated by ).

Bothridia cup-shaped, bo.ri incomplete, bo.to present, clearly discernible (Figures, 46, 47, 51). Sensillus uncinate, arched, curving upward (Figure 45, 46, 47). Pd I: prominent extended lamina, rounded apex; Pd II: small ovoid lamina (Figures 40, 46, 47); h.ap long extending structure, rounded apex, basally curved; anterior tip overlapping posterior bothridial posterior part (Figures 40, 46, 47).

Notogastral promontories and setae very clearly discernible (Figures 47, 52, 53).

Only lyrifissures ih and ips clearly visible. Discidium easily discernible as polyhedral structure with rounded apex. Several depressions (dep) clearly discernible behind acetabulum IV; one of them elongated, concealing the tarsus during leg folding process (Figure 40).

Ventral region. Infracapitulum with setae h, m, a clearly visible (Figures 39, 55). Epimeres slightly elevated, delimited by shallow furrow (bo.1, bo.2, bo.sj). In medial zone a series of aligned depressions (Figure 54 indicated by ); Apodemes (apo.1, apo.2, apo.sj, apo.3) well discernible (Figures 39). Epimeral chaetotaxy 3 –1-3– 3; Pd I, Pd II and dis well discernible; a.g.f clearly visible, situated anteriorly to genital fig (Figures 39, 54). Genital fig small relative to anal fig (Figures 54, 57); four pairs of long genital setae (Figure 57); anal fig with two pairs of small but clearly discernible setae; fig terminating in small sharp tip (Figure 57, indicated by ); ag and ad3 equal in length; ad2 and ad1 situated laterally at level of posterior end of anal fig (Figure 57). Lyrifissure iad not discernible. Particular depression behind acetabulum IV (Figure 39 indicated by ). Several large depressions laterally to anal and genital figs and marginally to ventral shield (Figures 39, 54, 57).

Posterior view. This view permits clarification of several aspects such as: a) shape of the e.i.p and large depression in the anterior medial zone (Figure 58 indicated by ); b) shape and depth of p.p.d (Figure 58); c) shape and disposition of d.sj (Figure 58, 62 indicated by ); d) disposition of the transversal cuticular folds situated behind d.sj (Figures 58, 59, 62, indicated by ); e) disposition, shape and distribution of setae and cuticular ornamentations on elevated notogastral zone (Figures 58, 59, 62). f) disposition of sc and the zone with irregularly elongated protuberances (Figures 58, 61 indicated by ).

Legs (Figures 64-72). All legs monodactyle. Setal formulae I (1-4-2-4-16-1) (1-2-2) (Figure 67); II (1-4-3-2-15-1) (1-1-2) (Figure 64) III (2-3-1-2-13-1) (1-1-0) (Figure 70); IV (1-2-2-2-12-1) (0-1-0) (Figure 69).

Seta d of tibia I associated with φ 2 (Figure 68). Setae d on tibia II small (Figure 65), situated behind φ, not associated with solenidion; setae d, genu II (Figure 66), large, situated behind and associated with σ. Femur III with femoral groove f.g, difficult to observe in antiaxial view (Figure 70), but well developed, containing seta v (Figure 71); disposition of setae on tarsus III: (u), s, (a) (Figure 72) particular s situated anterior to (a). Femur IV presenting a conspicuous ventral carina (Figure 69).