Ceratorchestes (Ceratorchestes) tripartitus, Ermilov, 2024

Ermilov, Sergey G., 2024, New Ceratorchestes (Acari, Oribatida, Peloppiidae) from Venezuela, Zootaxa 5506 (4), pp. 555-566 : 556-559

Ceratorchestes (Ceratorchestes) tripartitus sp. nov.

( Figs 1 , 2 )

Material. Holotype (female) and eight paratypes (five males and three females): northern Venezuela, Aragua State, Rancho Grande , 1450 m a.s.l., leaf litter, 26.II.1995 ( R. W. Brooks).

The holotype is deposited in the collection of the Canadian National Collection, Ottawa, Canada; eight paratypes are deposited in the collection of the Tyumen State University Museum of Zoology , Tyumen, Russia. All specimens are preserved in 70% solution of ethanol with a drop of glycerol.

Diagnosis. Body length: 390–450. Rostrum tripartite; rostral protrusions triangular, simple, similar in size. Lateral tooth of prodorsum strong. Lamellar cusp with well-developed lateral tooth and rounded medial part; translamella present. Rostral and lamellar setae medium-sized, setiform, barbed; interlamellar seta long, slightly thickened, stiff, acuminate, barbed; bothridial seta long, setiform, shortly ciliated. All notogastral setae (except minute c) slightly thickened, stiff, acuminate, barbed; p 1 – p 3 shorter than others. Epimeral setae 1b, 1c, 3b medium-sized, longer than others, slightly thickened, stiff, acuminate; 3a inserted posterolaterally to 2a. Adanal lyrifissure slightly oblique to anal plate. Leg trochanter IV rounded dorsoanteriorly.

Description of adult. Measurements. Body length: 450 (holotype), 390–420 (male paratypes), 435–450 (female paratypes); body width: 360 (holotype), 300–345 (male paratypes), 360 (female paratypes).

Integument. Body color light brown. Surface densely microgranulate sculpturing (visible only under high magnification in dissected specimens; × 1000); lateral part of prodorsum between bothridium and acetabula I–III with larger granules (diameter up to 1).

Prodorsum ( Figs 1A, C ). Rostrum tripartite; all rostral protrusions triangular, slightly rounded apically, similar in size or medial part slightly longer. Lateral tooth of prodorsum tp strong. Lamella about 2/3 length of prodorsum; lamellar cusp with well-developed lateral tooth and rounded medial part; translamella short, lineate; sublamella not observable. Rostral (34–45) and lamellar (52–64) setae setiform, barbed; rostral seta inserted medial to tutorial end and distanced from it; interlamellar seta (75–94) slightly thickened, stiff, acuminate, barbed; bothridial seta (110–131) setiform, shortly ciliated; exobothridial seta (26–30) setiform, thin, roughened.

Notogaster ( Figs 1A, C ). Anterior notogastral margin convex medially. Notogastral seta c (4) needleform; other notogastral setae (la, lm, lp, h 1 – h 3: 94–105; p 1 – p 3: 67–75) slightly thickened, stiff, acuminate, barbed. Opisthonotal gland opening and all lyrifissures well observable.

Gnathosoma ( Figs 2A–C ). Subcapitulum size: 101–105 × 86–90; subcapitular setae a (19–26), m (22–26) setiform, roughened; h (26–30) slightly thicker, setiform, barbed; both adoral setae (7) setiform, thin, smooth. Palp length: 79–82; setation: 0-2-1-3-9 (+solenidion); postpalpal seta (6) spiniform, smooth. Chelicera length: 90–97; teeth of both digits indistinct; setae (cha: 30–32; chb: 17–19) setiform, slightly barbed.

Epimeral and lateral podosomal regions ( Figs 1B, C ). Epimeral formula: 3-1-3-5; 1b, 1c, 3b (56–64) slightly thickened, stiff, acuminate, barbed; 3c (26–34), 4b, 4c (22–26) setiform, slightly barbed; 4d (30–37) setiform, barbed; 1a, 2a, 3a, 4a (19–22), 4e (22–26) setiform, thin, roughened; 3a inserted posterolaterally to 2a (not in the same oblique row with setae of epimere IV).

Anogenital region ( Figs 1B–D ). Anogenital formula: 6-1-2-3; genital setae (g 1: 22–30; g 2 – g 6: 15–22) setiform, roughened; aggenital (28–30), anal (26–30) setae and adanal setae ad 2, ad 3 (28–30) setiform, barbed; adanal seta ad 1 (45–49) slightly thickened, stiff, acuminate, barbed. Genital and anal plates in females noticeably larger than in males. Adanal lyrifissure close and slightly oblique to anal plate. Ovipositor is typical for Ceratorchestes ( Ermilov et al. 2016) : size: 131–138 × 49–52; length of blade: 64–67; length of distal section (beyond middle fold): 67–71; setae ψ 1, τ 1 (56–60) setiform, smooth; setae ψ 2, τ a, τ b, τ c (26–00) and six coronal setae (30–34) narrowly thorn-like.

Legs ( Figs 2D–G ). Median claw noticeably larger than lateral claws; all claws slightly barbed on dorsal side. Porose area on all segments not observable. Formulas of leg setation and solenidia: I (1-5-3-4-20) [1-2-2], II (1- 4-3-4-16) [1-1-2], III (2-3-1-3-15) [1-1-0], IV (1-2-2-3-12) [0-1-0]; homology of setae and solenidia indicated in Table 1 ; solenidion ω 1 on tarsus I, ω 1 and ω 2 on tarsus II and σ on genu III slightly thickened, rounded distally; other solenidia setiform.

Remarks. The new species is similar to C. (C.) setosus Balogh & Mahunka, 1969 (in Balogh & Mahunka 1969a; see also Ermilov et al. 2016) in the presence of the tripartite rostrum and lateral tooth on the lamellar cusp and in the absence of large dorsoanterior triangular process on the leg trochanter IV, but differs from the latter by larger body size (length: 390–450 versus 328–348), the presence of the well-developed tooth (versus minute) on lateral side of the prodorsum, in the morphology of the rostrum (all rostral parts similar in length versus lateral parts longer than medial part) and dorsoanterior part of the leg trochanter IV (rounded versus with small tooth), and in the length and morphology of the epimeral seta 3c (short, setiform versus medium-sized, thickened).

Etymology. The specific epithet tripartitus refers to the tripartite rostrum.

Figures

FIGURE 1. Ceratorchestes (Ceratorchestes) tripartitus sp. nov., adult, male (A–C) and female (D): A—dorsal view (legs omitted); B—ventral view (legs omitted); C—right lateral view (gnathosoma and legs omitted); D—anogenital region. Scale bar 100 μm.

FIGURE 2. Ceratorchestes (Ceratorchestes) tripartitus sp. nov., adult: A—subcapitulum, ventral view; B—palp, left, paraxial view; C—chelicera, right, antiaxial view; D—leg I (trochanter omitted), left, paraxial view; E—leg II, right, antiaxial view; F—leg III, left, antiaxial view; G—leg IV, left, antiaxial view. Scale bars 20 μm (A, C), 10 μm (B), 50 μm (D–G).