Congocepheus kayoveae, Fernandez, Nestor, Theron, Pieter & Leiva, Sergio, 2016

Fernandez, Nestor, Theron, Pieter & Leiva, Sergio, 2016, Revision of the family Carabodidae (Acari, Oribatida) V. Fourth part. Two new species of the genus Congocepheus from the Republic of Rwanda: Congocepheusrwandensis sp. n., and Congocepheuskayoveae sp. n., ZooKeys 556, pp. 19-41 : 25-29

Taxon classification Animalia Oribatida Carabodidae

Congocepheus kayoveae sp. n. Figures 19-24, 25-28, 29-33, 34-38, 39-43, 44-47; Table 2

Etymology.

The specific epithet is derived from Kayove, Rwanda, where the type material was collected.

Material examined.

Holotype Female. "73/2. Kayove- Rwanda; 2100 mts. 15/V/1973" Leg. P.Werner; material deposited in the Collection of the Natural History Museum of Geneva (MHNG), Switzerland; preserved in 70% ethanol. Four adult female paratypes, same locality and date as holotype; deposited in Collection of MHNG; preserved in 70 % ethanol. Material studied by SEM: six specimens, not deposited.

Diagnosis adult female.

Integumental microsculpture: notogaster with irregular cord-shaped structures and elongate fingerlike projection.

Setation: simple: epimeral, genital, aggenital, anal, adanal, subcapitular; one central dentate vein, margin dentate: notogastral; two dentate veins, margin dentate: rostral, interlamellar; flat setae, margin dentate, central dentate vein: lamellar.

Prodorsum: elevated interlamellar process complete; margin of laterodorsal lamellae slightly elevated. Prominent triangular lamellar tip, lamellar setae situated externally; shallow lamellar furrow terminating near internal limit of lamellar tip. Tutorium spoon-shaped, larger than Pedotectum I. Rostrum: rounded undulate margin, wide, large, projecting forward. Epimera elevated, delimited by deep furrow; deep hollow paraxially to epimere 1; epimeres 3 and 4 unfused. Epimeral chaetotaxy 3-1-3-3. Genital plate rounded; four or five pairs of genital setae; aggenital setae posterior to genital opening, far from ad3.

Description.

Measurements. SEM: 464 μm (462-467) × 173 μm (172-180) (measurements on six specimens). Light microscopy: 467 μm (465-468) × 175 μm (173-183) (measurements on five specimens).

Shape. Elongate oval (Figure 19). Colour. Specimens without cerotegument; light brown to yellowish-brown when observed in reflected light.

Cerotegument. Present: thin amorphous layer (0,3-0,5 μm) on prodorsum, notogaster, ventral region; with adhering soil particles principally on e.i.p and central notogastral zone (Figures 19, 21, 22, 23, 24). Observation of cuticular ornamentation not impeded by cerotegumental layer (Figures 20, 22, 29, 31). Absent: bothridial ring (bo.ri) (Figure 20).

Integument. Pusticulate (Figure 22): prodorsum: e.i.p posterior zone, lamellar margin and bothridial zone; central notogastral zone and humeral apophysis (Figures 19, 20, 29); legs: femurs (Figure 38). Smooth to granulate: prodorsum: anterior e.i.p (Figure 19); notogaster: s.c, b.ng zone (Figure 29); lateral zone: Tu, s.tu.d, Pd I, Pd II. Ventral zone: subcapitulum, epimeral, genital, anal and dep (Figures 29, 30, 31, 34, 39, 40, 41, 42). Series of irregular c.s.s. on notogastral zone, forming central elongate f.l.p (Figures 25, 28) (described in detail under notogaster), well visible without cerotegumental layer.

Setation. Simple: epimeral (Figures 39, 43), genital (Figures 40, 42), aggenital (Figure 42), anal, adanal (Figure 41), subcapitular (Figure 34) and seta of genu, tibia and tarse of legs. One central dentate vein and dentate margin: notogastral (Figures 32, 37); two types of notogastral setae: large c1, c2, dp, h1, with upward directing dentate margin (Figure 37); small da, dm, la, lm, lp, h2, h3, p1, p2, p3, dentate margin not directing upward (Figure 32). Two dentate veins and dentate margin (Figures 21, 24), ro (Figure 21), in setae (Figure 24). Flat setae, dentate margin with central dentate vein: le setae (Figure 36), superior margin presenting few teeth; numerous large teeth on inferior margin. Barbate, with central dentition: large femoral setae (legs I-IV) (Figure 38).

Prodorsum. Polyhedral (dorsal view) (Figure 19); slightly convex polyhedral in lateral view (Figure 29); triangular in frontal view (Figure 35). Elevated interlamellar process (e.i.p.) almost flat in dorsal view (Figures 19, 25); large surface between p.p.d and in setae insertion zone (Figures 19, 29, 35), flat in frontal view (Figure 35) (see Remarks); in setae (Figure 24) large (82 μm ± 5), curving, directing backward (Figures 19, 29, 30, 31, 35), setae inserted anteriorly on e.i.p. (Figures 29, 30, 31) at same longitudinal level as ro insertion (Figure 35); ro setae (Figure 21) length (38 μm ± 3 μm), directing forward and paraxially (Figures 29, 30), curving downward (Figures 29, 36) with criss-crossing tips (Figures 21, 30, 35); le setae lateral (Figures 29, 35, 36), length (58 μm ± 3), wider zone (10 μm ± 2); ro and le setal insertion at same level.

Sensillus (si) (Figure 20) (66 μm ± 3) uncinate, curving upward (Figures 29, 30, 31, 35). Bothridial ring (bo.ri) smooth, well defined, with bothridial tooth (Figure 20).

Rostral margin slightly rounded, margin undulate (Figure 30 indicated byJ; 35 indicated by Y).

Lamellae running dorsolaterally (Figures 26, 27); semicircular shallow lamellar furrow (l.l.f) originating on bothridial zone and terminating near lamellar tip (la.ti), clearly discernible when cerotegumental layer absent (Figures 26, 27). Posterior prodorsal depressed zone (p.p.d) large, normal (Figures 19, 25).

Notogaster. Ovoid in dorsal view, with slight constriction at level of da, la setae (Figure 19); in lateral view zone anterior to da, la setae slightly depressed, rest convex (Figure 29); d.sj narrow, slightly rectilinear, well delimited (Figure 25); notogastral anterior depression (n.a.d) reduced (Figures 19, 25).

Fourteen pairs of setae: c1, c2, da, dm, dp, la, lm, lp, h1, h2, h3, p1, p2, p3; c1 (86 ± 5 μm); c2 (75 ± 5 μm) both setae long and thin, direction variable but in most cases directing forward (Figure 19, 31, 35), however not uncommon for these setae to be directing backward (Figure 29). Setae da (35 ± 3 μm); dm (30 ± 3 μm); dp (65 ± 3 μm); la (35 ± 3 μm); lm (27 ± 3 μm); lp (42 ± 3 μm); h1 (48 ± 3 μm); h2 (45 ± 3 μm); h3 (25 ± 3 μm); p1 (13 ± 3 μm); p2 (15 ± 3 μm); p3 (17 ± 3 μm).

Cord-shaped structures (c.s.s) converging in central anterior zone forming an elongate fingerlike projection (f.l.p) (53 ± 5 μm (Figure 25). Circumgastric depression (s.c) present, clearly visible (Figures 19, 29), from h.ap surrounding notogaster, situated between la, lm, lp, h2, h1 and h3, p3, p2, p1 setae (Figure 19). Humeral apophysis (h.ap) large elongate projection (Figure 19).

Lateral region (Figures 29, 31). Lamellae (lam) easily discernible; cuticular microsculpture near bothridial zone pusticulate with several round depressions (Figure 20); le setal insertion at same level as ro setal insertion; conspicuous la.ti (Figures 25, 26, 35) (details in frontal view).

Tutorium (tu) prominent lamina, curving margin, clearly discernible, smooth cuticula (Figures 29, 31). Deep supratutorial depression (s.tu.d) running parallel to and between lamellae and tutorium; p.tu.d and a,tu d present, large (Figure 31). Tu larger than Pd I, expanded laterally (Figure 31).

Bothridial ring (bo.ri) smooth, with bo.to, hardly discernible due to positioning of lateral antiaxial setae (l") of genu II (Figure 20) (see Remarks); h.ap triangular, inferior margin rounded; anterior zone of h.ap overlapping posterior bothridial zone (Figures 20, 29).

Clearly delimited zone on s.c with more or less smooth cuticula, immediately followed by clearly delimited pusticulate zone (Figure 29), and slightly below insertion of setae h3, p3, p2, p1 to h.ap, a smooth zone extending to b.ng. Clearly delimited depressed zone behind leg IV. Cuticular ribbon (Figure 29 indicated by X) parallel to b.ng.

Frontal view (Figures 26, 27, 30, 35). Actual shape and disposition of: e.i.p, in setae, Lam, le setae, la.ti, Tu, Pd I, s.tu.d. and characteristics of rostral margin visible in frontal view.

Complete, flat e.i.p (Figure 35); in setae placed far from e.i.p margin; Lam present slightly higher up on margin, terminating anteriorly in large triangular la.ti, with le setae situated in the external limit of la.ti (Figures 30, 35) and the l.l.f terminating near internal limit of la.ti (Figure 26, 27). Insertions of ro and le setae at the same transverse level (Figure 34). The l.l.f is only clearly discernible under optical observation (Figures 26, 27); in SEM observation the zone between l.l.f and lamellar margin is a slightly flat zone (Figure 30). Laterally expanded spoon-shaped Tu appearing larger than Pd I (Figures 30, 35); very deep s.tu.d completely concealing leg I (Figure 30). Rounded, undulate rostral margin with prominent forward extension, parallel to Tu, extending backward Pd I level (Figures 30, 35) (See Discussion).

Ventral region (Figures 34, 39, 40, 41, 42, 43). Large, clearly discernible rostral margin (Figure 34 indicated by X). Elevated epimera delimited by deep furrow (Figure 39); deep hollow zone paraxial to epimere 1(Figure 39, indicated by K); complete epimere sj; epimera 3 and 4 well discernible, unfused. Epimeral chaetotaxy 3-1-3-3. Epimeral setae 1a, 2a, 3a, 4a, largest. Discidum clearly discernible; a.g.f clearly visible, situated anterior to genital plate (Figure 40). Genital plate rounded, with four or five pairs of genital setae, (see Remarks) (Figures 40, 42); all setae more or less equal in length; ag setae situated posterior to genital opening, far from ad3 (Figure 39). Three pairs of ad seta, more or less equal in length (Figure 41); anal plate polyhedral (Figure 41), sharply tipped; two pairs of anal setae; anterior pairs larger than posterior. Shallow depressions (dep) (Figure 39) situated laterally on either side of as well as between genital and anal openings. Subcapitulum diarthric (Figure 34); setae h largest.

Legs (Figures 44-47). All legs monodactyle. Setal formulae I (1-4-2-4-16-1) (1-2-2); II (1-3-3-3-15-1) (1-1-2); III (2-3-1-2-14-1) (1-1-0); IV (1-2-2-3-12-1) (0-1-0). See Table 2.

Remarks.

In some specimens the cerotegumental layer appears damaged (Figure 33), as more than 40 years have passed since collection, preservation of specimens may have been influenced by the quality of the initial diluted alcohol. Material of much greater age has been studied previously without problems, but in this case, the description of the cerotegumental layer must be regarded as provisional.

Twisting setae complicate and obscure observation; use of SEM vital in providing adequate information, while small particles adhering to setal surfaces further compli cate observation. In several cases study material presents slight genital neotrichy; in two instances five pairs of setae were observed. One example of neotrichy was observed in Congocepheus , with notogastral neotrichy present in Congocepheus germanicus ; but Congocepheus kayoveae is the first observed occurrence of genital neotrichy.