Congocepheus setiformis Ermilov, 2025

ErmilovK, Sergey G. & RybalovK, Leonid B., 2025, New faunistic data on oribatid mites (Acari, Oribatida) from western, southern and southeastern Ethiopia, with description of two new species of the family Carabodidae, Acarologia 65 (2), pp. 559-574 : 569-572

Congocepheus setiformis Ermilov n. sp.

Zoobank: 1B2C9206-2CCE-4309-AF17-5D9B43984037

( Figures 4 , 5 )

Type material — Holotype (male) and six paratypes ( three males and three females): Southern Ethiopia, South Ethiopia Regional State, Gamo Zone, 6°01′36.7″N, 37°35′42.7″E,

1170 m a.s.l., 5 km East from the town Arba Minch, 1 km from the lake Abai, litter in a mixed forest on the terrace (first layer of forest: Celtis sp. , Ficus sycomorus , Schefflera sp. , Acacia

sp.; second layer of forest: Lemon sp. , Coffea arabica ) on brown (black-brown) soil with light-medium loam soil texture, 7.XII.2018, dry season (L.B. Rybalov).

The holotype is deposited in the collection of the Senckenberg Museum of Natural History, Görlitz, Germany ; six paratypes are in the collection of the University of Tyumen, Museum of Zoology, Tyumen, Russia. All specimens are preserved in 70% solution of ethanol with a drop of glycerol.

Diagnosis — Body length: 375–450. Notogaster with specific system of comparatively sparse ridges and depressions; two anteromedial ridges fused distally. Lamella rounded distally; translamella present. Dorsocentral prodorsal region distinctly hump-like; mediobasal prodorsal part with large depression. Rostral seta medium-sized, phylliform, barbed, inserted on translamella; lamellar seta medium-sized phylliform, covered by strong spines, inserted in ventrodistal part of lamella; interlamellar seta long, phylliform, barbed; bothridial seta medium-sized, setiform, heavily barbed. Fourteen pairs of phylliform, barbed notogastral setae: c 2, dp longest; p 1, p 2, p 3, h 3 shortest; other setae medium-sized; c 2 directed forward. Epimeral setae 1a, 1c, 2a, 3a and anal setae short, spiniform; genital setae short, setiform, nearly smooth; other epimeral setae well as aggenital and adanal setae short, setiform, slightly barbed; ad seta 3

in preanal position. Leg tarsus IV with 12 setae; seta l″ of genua I, II and l′ of genua III, IV phylliform.

Description — Measurements. Body length: 375 ( holotype), 375–450 (male and female paratypes); notogaster width: 210 ( holotype), 210–255 (male and female paratypes). Body ratio (length/width): ≈ 1.7–1.9. No difference between males and females in size.

Integument ( Figs 4 (a–e)) — Body color light grey to dark brown. Body surface nearly smooth, covered by thin layer of dense microgranulate cerotegument. Notogaster and anogenital region with specific system of ridges and depressions; two oblique anteromedial notogastral ridges fused distally.

Prodorsum ( Figs 4 (a, b, d)) — Rostrum broadly rounded. Lamella long and broad, rounded distally; translamella present (observed in dorsal aspect); tutorium long (slightly shorter than lamella), ridge-like. Dorsocentral region distinctly hump-like; mediobasal part with large depression. Rostral seta (37–41) phylliform, dilated in median part, barbed, inserted on distinct tubercle (tubercle located on translamella); lamellar seta (37–41) phylliform, dilated in median part, covered by strong spines, inserted in ventrodistal part of lamella; interlamellar seta (75–82) phylliform, dilated mediobasally or in median part, barbed; bothridial seta (52–56) setiform, heavily barbed, curved mediodistally; exobothridial seta not observed. Bothridium interrupted ventrally.

Notogaster ( Figs 4 (a, d, e)) — Anterior margin slightly convex medially; lateral and posterior parts slightly depressed. Humeral shoulder small, well visible. Fourteen pairs of notogastral setae ( c 3 absent; c 2, dp: 82–90; p 1, p 2, p 3, h 3: 37–41; others: 67–71) phylliform, dilated mediobasally or in median part, barbed; c 2 directed forward; c 1 located medial to c 2. Opisthonotal gland opening and all lyrifissures visible.

Gnathosoma ( Figs 5 (a–c)) — Subcapitulum size: 94–97 × 75–79; subcapitular seta h (9–11) setiform, slightly barbed; a (11–15) and m (11–15) narrowly phylliform, slightly dilated in median part, slightly barbed. Palp length: 60–64; setation: 0-2-1-3-9(+ω); postpalpal seta (7) spiniform, roughened. Chelicera length: 109–112; seta cha (30–34) setiform, barbed; seta chb (15–17) setiform, roughened.

Epimeral and lateral podosomal regions ( Figs 4 (c, d)) — Epimeral setation: 3-1-3-3; setae

1a, 1c, 2a, 3a (4) spiniform, smooth; other setae 1 ( b: 30; others: 19–22) setiform, slightly barbed. Discidium tubercle-like.

Anogenital region ( Figs 4 (c–e)) — Anogenital formula: 4-1-2-3; all genital setae (11–15) setiform, nearly smooth; aggenital and adanal setae (19–22) setiform, slightly barbed; seta ad 3

in preanal position, posterior to aggenital seta; both anal setae (4) spiniform, smooth. Adanal lyrifissure distanced from anal plate.

Legs ( Figs 5 (d–g)) — Claw of each leg strong, barbed dorsally, with small ventrobasal tooth. Dorsoparaxial porose area on femora I–IV elongate oval. Formulas of leg setation and solenidia: I (1-4-3-4-16) [1-2-2], II (1-4-3-3-15) [1-1-2], III (2-3-1-2-15) [1-1-0], IV (1-2-2-2-

11) [0-1-0]; homology of setae and solenidia indicated in Table 2 ; seta s of tarsus I eupathidial; seta l″ of genua I, II and l′ of genua III, IV phylliform, dilated in median part; solenidion 1 φof tibia I long, subflagellate; ω 2 long, rod-like; other solenidia medium-sized or short, thickened, rounded distally.

Remarks — Congocepheus setiformis Ermilov n. sp. is most similar to C. rwandensis Fernández, Theron and Leiva, 2016 from the Afrotropical region in having setiform bothridial seta and the presence of one pair of long notogastral setae of c -row directed forward. However, the new species differs from the latter by the seta c 2 (versus c 1) directed forward and a significantly smaller number of ridges and depressions on the notogaster.

Etymology — The species name setiformis refers to the morphology of the bothridial seta (setiform).

Figures

Figure 4 Congocepheus setiformis Ermilov n. sp., adult: a–dorsal view; b–anterior part of prodorsum, anterior view; c–ventral view (gnathosoma and legs omitted); –dright lateral view (legs omitted); – eposterior view (part of left half omitted). Scale bar 100 μm.

Figure 5 Congocepheus setiformisErmilov n. sp., adult: a–subcapitulum, ventral view; b–palp, left, paraxial view; c–chelicera, left, paraxial view; d–leg I, right, antiaxial view; e –leg II (tarsus omitted), right, antiaxial view; – fleg III (tarsus omitted), left, antiaxial view; g –leg IV, left, antiaxial view. Scale bars 20 μm (a, c–g), 10 μm (b).