Neoribates protrusus, Ermilov & Starý, 2017

Ermilov, Sergey G. & Starý, Josef, 2017, New Neoribates (Acari, Oribatida, Parakalummidae) from Vietnam, Zootaxa 4303 (1), pp. 51-72 : 65-70

Neoribates protrusus sp. nov.

( Figs 28–36)

Diagnosis. Body size: 913–946 × 747. Rostrum protruding, narrowly rounded. Rostral, lamellar and bothridial setae setiform, barbed, le inserted on prodorsum, laterally to lamellar ends. Interlamellar setae setiform, with attenuate tips, barbed. Ten pairs of notogastral setal alveoli or microsetae. Epimeral setae thin, slightly barbed, 3с and 4c longest. Genital and aggenital setae setiform, anal and adanal setae flagellate, all smooth, ad 3 inserted in preanal position. Legs tridactylous, lateral claws with one tooth ventrodistally.

Description. Measurements. Body length: 946 (holotype, female), 913 (one paratype: one female); notogaster width: 747 (holotype), 747 (paratype).

Integument. Body color dark brown. Body surface (including pteromorphs, genital and anal plates, subcapitular mentum and genae and leg segments) densely microporose (visible under high magnification, ×1000). Lateral parts (between bothridia and acetabula) microgranulate.

Prodorsum ( Figs 28–30). Rostrum distinctly protruding, narrowly rounded. Lobe with projects, creating one inner rostral tooth. Rostrophragmata relatively thick. Lamellae located dorso-laterally, half as long as prodorsum (measured in lateral view), their ends curving anteromedially. Translamellar line represented by two rudimentary parts near lamellae. Sublamellae are two thirds of the lamellae. Sublamellar porose areas oval (28–32 × 16–20), partially covered by sublamellae. Rostral (110–118), lamellar (196–205) and bothridial (225) setae setiform, barbed, le inserted on prodorsum, laterally to lamellar ends. Interlamellar setae (291–299) setiform, with attenuate tips, barbed. Exobothridial setae and their alveoli absent. Sejugal porose areas oval, transversely elongated. Anterior and posterior ridges distanced from each other, ar simple, pr bifurcate. Lateral ridges poorly visible.

Notogaster ( Figs 28, 30–32 ). Anterior notogastral margin convex medially. Dorsophragmata comparatively short, longitudinally elongated. Ten pairs of notogastral setae represented completely by microsetae (2) or alveoli. Four pairs of sacculi with small openings. Setae lp inserted posteriorly and close to S1. Lyrifissures and opisthonotal gland openings clearly visible.

Gnathosoma ( Figs 29 , 30 ). Generally, similar to Neoribates pseudojacoti sp. nov. Subcapitulum longer than wide (168–176 × 139–143). Subcapitular setae setiform, m and h similar in length (45–53), barbed, slightly thinner than a (24–32) sparsely barbed. Two pairs of adoral setae (20) setiform, heavily barbed. Palps (length 110–114) with setation 0–2–1–3–9(+ω). Postpalpal setae (10) spiniform, smooth. Chelicerae (length 184–192) with two barbed setae, cha (65) longer than chb (41). Trägårdh’s organs long, tapered.

Epimeral and lateral podosomal regions ( Figs 29–31 ). Epimeral setal formula: 3–1–3–3. Setae setiform, thin, slightly barbed, 3с and 4c (53–61) longer than 1b, 3b, 4a and 4b (41–49), 1a, 2a and 3a (36–41) and 1c (10–12). Pedotecta I and II small, lamina-like, Pd II rectangular in ventral view, rounded anteriorly. Discidia triangular, broadly rounded distally. Circumpedal carinae long, reaching anterior margin of ventral plate.

Anogenital region ( Figs 29–32 ). Five pairs of genital and one pair of aggenital setae similar in length (41–49) setiform, smooth. Two pairs of anal (98–110) and three pairs of adanal (131–151) setae flagellate, smooth. Setae ad 3 inserted in preanal position. Adanal lyrifissures located close and parallel to anal plates. Preanal organ bifurcate distally, trapezoid in ventral view. Marginoventral porose area represented by numerous rounded or elongate oval parts.

Legs ( Figs 33–36 ). Generally, similar to Neoribates pseudojacoti sp. nov. Tridactylous, median claw thicker than laterals, all barbed dorsally. Lateral claws with one tooth ventrodistally. Dorsoparaxial porose areas on femora and trochanters III, IV, posteroventral porose areas on tarsi and anteroventral porose areas on tibiae well visible. Formulas of leg setation and solenidia: I (1–5–3–4–20) [1–2–2], II (1–5–3–4–15) [1–1–2], III (2–3–1–3–15) [1–1– 0], IV (1–2–2–4–12) [0–0–0]; homology of setae and solenidia indicated in Table 1. Solenidia ω1 on tarsi I, ω1 and ω2 on tarsi II and σ on genua II, III thickened, blunt, other solenidia longer, setiform. Famuli short, straight, dilated and truncated distally, inserted between ω2 and ft”. Thick setae on leg segments absent.

Roman letters refer to normal setae, Greek letters to solenidia (except ɛ = famulus). Single prime (’) marks setae on the anterior and double prime (”) setae on the posterior side of a given leg segment. Parentheses refer to a pair of setae. Trtrochanter, Fe—femur, Ge—genu, Ti—Tibia, Ta—tarsus.

Material examined. Holotype (female) and one paratype (one female): Northern Vietnam, Tam Dao National Park, 1000 m a.s.l., agrobiocenose, orange orchard with orange tree, leaf litter sample (No. VIE-118), 16.X.1988 (collected by J. Starý & Nguen Tri Tien).

Type deposition. The holotype and one paratype are deposited in the collection of the Tyumen State University Museum of Zoology , Tyumen, Russia.

Etymology. The specific name protrusus refers to the protruding rostrum.

Remarks. Neoribates protrusus sp. nov. is morphologically most similar to Neoribates rotundus Aoki, 1982 from Japan and Taiwan in having large body size, setiform bothridial setae and microsetae on notogaster (ventral side was not described by Aoki). However, the new species differs from the latter by the presence of barbed bothridial setae (vs. smooth), rudimentary parts of translamellar line (vs. absent) and very long interlamellar setae with attenuate tips (vs. shorter, setiform).

Also, Neoribates protrusus sp. nov. is similar to N. pararotundus Ermilov & Martens, 2014 from Nepal in general traits (body large; bothridial setae setiform; prodorsal setae long, in with attenuate tips; adanal setae ad 3 inserted in preanal position; five pairs of genital setae). The new species differs from the latter by the presence of 10 pairs of notogastral alveoli or microsetae (vs. 14 pairs of alveoli), long, flagellate adanal setae (vs. short, setiform), by localization of lamellar setae on prodorsum, laterally to lamellar ends (vs. on lamellar ends), and the absence of teeth on the lamellar ends (vs. present).

Figures

FIGURE 29. Neoribates protrusus sp. nov., adult: ventral view (legs not shown). Scale bar 100 µm.

FIGURES 30 – 32. Neoribates protrusus sp. nov., adult: 30 — anterior part of body, lateral view (legs not shown); 31 — posterior part of body, lateral view; 32 — ventroposterior view of notogaster and posterior part of anoadanal region. Scale bar 100 µm.

FIGURES 33 – 34. Neoribates protrusus sp. nov., adult: 33 — leg I (trochanter covered by pedotectum I), right, antiaxial view; 34 — genu, femur and trochanter (covered by pedotectum II) of leg II, right, antiaxial view. Scale bar 50 µm.

FIGURES 35 – 36. Neoribates protrusus sp. nov., adult: 35 — genu, femur and trochanter of leg III, left, antiaxial view; 36 — leg IV, left, antiaxial view. Scale bar 50 µm.