Neocarus kayapo, Bernardi, 2023

Bernardi, Leopoldo F. O., 2023, Neocarus kayapo, a new species of Opilioacaridae (Parasitiformes) from Brazilian caves, Persian Journal of Acarology 12 (1), pp. 417-430 : 419-425

Neocarus kayapo sp. nov. ( Figs. 2–8 )

http://zoobank.org/ urn:lsid:zoobank.org:act:62ACF56D-180C-48C9-A078-8B5BB929872E

Diagnosis

Palp tarsus with 5 foliate setae, each of which with 4 or 5 lobes; st1, st2, st3 and st5 tapering and ribbed; female pregenital and genital area with barbed and stout setae, ovipositor without setae, but with two pairs of smooth projections, placed apically and laterally. Male pregenital area with smooth and tapering setae and/or barbed and tapering setae and/or stout and ribbed setae, genital area with barbed and tapering setae. Male and female present multiple setae on basal portion of chelicera (cht). Sexual dimorphim presents in male palpal genu with 13–15 smooth setae, and female carrying only 1–3 smooth setae.

Description

Chelicera ( Fig. 2 ) – Basal segment with multiple setae 2–4 (cht 1) (in the same specimen, the number of setae varies, the left chelicera may have more or fewer setae than the base of the right chelicera), fixed digit with 3 setae (ch 1 '', ch 2 ' and ch 2 ''). Dorsal (id) and antiaxial lyrifissure (ia) well-developed. Fixed digit with 2 teeth, and movable digit with 1 large tooth and a well-developed terminal hook. Movable digit with one small ventral denticles, ogc present.

Subcapitulum ( Fig. 3 ) – Males and females with all 4 pairs of paralabial setae present: pl1 small, conical; With's organ (pl2) discoid, membranous; rutella (pl3) inserted dorso-laterally, with 5 distinct teeth; pl4 very small, conical, inserted dorsally on subcapitulum. All 4 pairs of circumbuccal setae (cb) with bifurcate tips; and 9–11 median and subcapitular (vm (in part), lvm, ldm, vp, lvp) setae, in female one pair of circumbuccal setae with a rounded tip (vp). Setae vm1 robust with a rounded tip. Lateral lips with distinct canals (dl1, dl2) and their orifices (ogl1, ogl2).

Palp ( Figs. 4–5 ) – Trochanter with 4 ribbed setae (= r - type). Femur with 12–15 r- type, 7–13 p - type setae and 1–2 smooth setae. Genu with dimorphism, male carrying 46–49 r - type, 0–1 p - type setae and 12–15 smooth (s - type) setae, and female carrying 39 r - type, 1 p - type setae and just 1 smooth (s - type) setae (fewer setae than male). Tibia with 35–42 r - type and 21–26 s - type (smooth or lightly barbed) setae. Tibia and tarsus partially fused.

In both sexes, tarsus setation including 4–5 d (leaf-like), and approximately 14–16 ch, 9–11 sm (one smooth and straight), 3–5 v1, and 1–2 v2 setae plus 3 solenidia (= s - type sensilla). Leaf-like setae

(d - type) with 3–4 large and distinct foliated lobs (the basal lob is smaller and triangular in shape). Modified sm3 - type sensilla on male palp tarsus absent. Lyrifissures iπ and iα distinct. Pretarsus with a pair of well-developed sessile claws.

Idiosoma – Dark blue Body and violet stripes on legs. Body often with brownish background reflecting ingested food.

Prodorsal shield – Anterior dorsal shield normal, with approximately 95–115 papilliform setae. Sexual dimorphism absent. Both sexes with two pairs of eyes, one pair of lyrifissures (probably j) observed. Rostrum rounded.

Opisthosoma – Dorsal idiosomal segments VII to XVI, without setae but with numerous lyrifissures arranged in transverse rows. Preanal segment (XVII) with 1 dorsal seta, plus two lateroventrals. Anal valves (segment XVIII) each with 8–11 setae.

Sternapophyses – Each digitiform structure with 2 pairs of setae, 1 small at tip and 1 long, barbed positioned more basally.

Sternitogenital region ( Figs. 7–8 ) – Sternal verrucae in adults each with 1 long, tapering (St1), and 2–3 ribbed and barbed setae. Remaining sternal area with 2 pairs of tapering (St2 and St3) and 4– 6 pairs of long, ribbed and barbed setae, and 3 pairs of lyrifissures (two pairs large, the third smaller; all different in shape and size from "standard" opisthosomal lyrifissures). Setae St2 slightly longer than St3. Pregenital capsules each with 1 long tapering seta (St5) and 4–6 ribbed setae. Pregenital area in male with, 4–5 ribbed setae with thin or blunt tip, genital area with 5–8 setae variable in shape, some of them smooth and pointed or lightly to strong ribbed and tapering, and blunt and ribbed setae. In females, pregenital with 2 ribbed and blunt setae and genital 6 ribbed and blunt setae. Male genital valves rectangular to rounded in shape. Ovipositor observed evaginated and in good condition, consisting of a tube-like structure with a central opening, with 2 pairs of small finger-like projections positioned laterally at the tip ( Fig. 7H ). Small gland-like structures present in the median portion. Male glands consist of 2 pairs of ovoid structures, one larger and one smaller, without reel-like structures.

Legs – Leg I longer than others. Telotarsus I has a highly modified group of dorsal setae located in the apical portion, close to the tarsal claws; ω1 conical, ω2 ligulate, ω3 subulate acuminate, ω4 acicular; ζ1 small with crown-like tip inserted close to sensilla group and ζ2 filiform with bifid tip. Acrotarsus II with a ribbed and bifurcate seta, one small solenidion (wa), and one long and smooth sensillum (probably also a solenidion) in dorsal portion. Acrotarsus III and IV carry on the dorsal portion only 3 long and barbed setae. Additionally, ventral portion of the acrotarsi II-IV with 3–4 pairs of setae. In addition to the standard set of 1 pair ventro-lateral and 1 dorso-lateral pair of setae, lateral portion of the acrotarsi II-IV with 2 pairs of setae. All pretarsi with one pair of claws and 2 pairs of setae, one pair long and curved, the other smaller and straight. Pretarsal ambulacrum rounded and smooth. Coronidia are present just on basitarsi of legs II to IV. Coronidia are short, smooth and strongly curved mid-dorsally.

Measurements – Female; Idiosoma: length 2307, width 1088; palp 772.8; chelicera length: basal segment 233, fixed digit 266, movel digit 83; leg I (not present); leg II: 2073; leg III: 2187; leg IV: 3078. Male; Idiosoma: length 2082–2106; palp: 669–775; chelicera length: basal segment 206– 273, fixed digit 256–280, movel digit 86–96; leg I 3382–3700; leg II: 2027–2136; leg III: 2151–2298; leg IV: 3131–3222.

Material examined

Holotype: female, deposited at ISLA/ UFLA (no 79115): Brazil, Minas Gerais State, Araxá city, CBMM _0001 (19° 41' 60.00" S, 46° 52' 55.92" W, DATUM WGS84 ), 13 Jan. 2021, Alves, JP . Paratypes: three males, deposited at ISLA / UFLA (no 79115) : Brazil, Minas Gerais State, Araxá city, CBMM _ 0001 (19° 41' 60.00" S, 46° 52' 55.92" W, DATUM WGS84 ), 15 May 2021, Alves, JP ; one male, deposited at MZLQ / ESALQ : Brazil, Minas Gerais State, Araxá city, SB-0009 (19° 40' 54.14" S, 47° 02' 55.88" W), 12 November 2022, Alves, JP .

Etymology

The species was named in honor of the indigenous people Kayapó, originally well distributed in the surrounding areas of the type locality.

Remarks

Neocarus kayapo sp. nov. presents a great variation of setal shape in the male genital area, similar to N. spelaion Bernardi and Borges-Filho, 2018 , N. simmonsi Bernardi, Zampaulo & Oliveira, 2020 and N. missiones Vázquez, Bernardi & Klompen, 2020 , but it differs from them by the presence of setae on the female pregenital area. In addition, N. kayapo sp. nov. differs from other Neocarus species by the presence of multiple setae on the base of the chelicera in male and female.

The ovipositor in this family is a unique a characteristic structure useful to differentiate Opilioacarida species. Neocarus kayapo sp. nov. presents a unique ovipositor cylindrical shape with 2 pairs of small finger-like projections.

Identifications of Neocarus species generally requires consideration of multiple characters simultaneously. Table 1 summarizes the comparative data and is provided to assist in the identification of the newly described species.

* number of setae in super adults. ** The description of Neocarus ojastii does not provide sufficient detail for an adequate comparison.

Setae type: sh: smooth setae; st/r: stout and ribbed setae; tp: tapering; tp/b: tapering and barbed setae; wb: weakly barbed setae.

Figures

Figure 2. Neocarus kayapo sp. nov. – Chelicera: A. Male; B. female. Abbreviations: cht = basal segment seta, ch = cheliceral setae, id = dorsal lyrifissure, iα = antiaxial lyrifissure.

Figure 3. Neocarus kayapo sp. nov. – Male subcapitulum. Abbreviations: cb = circumbuccal setae, pl = paralabial setae, lb = labrum.

Figure 4. Neocarus kayapo sp. nov. (male palp) – Palpal tarsus is not represented in detail. A–B. Tibia; C–D. Genu; E– F. Femur; G. trochanter. Abbreviations: p = papilliform setae, r = ribbed setae, s = smooth setae.

Figure 5. Neocarus kayapo sp. nov. – Male palp tarsus axial (A), antiaxial (B) view and detail of d-type setae (C).

Figure 6. Neocarus kayapo sp. nov. – specimens alive observed in a hypogean environment, cave CBM-0001, municipality of Araxá, Brazil.

Figure 7. Neocarus kayapo sp. nov. – A–D. Male genital setae; E. Male pregenital seta; F. Female genital seta; G. Female pregenital setae; H. Ovipositor.

Figure 8. Neocarus kayapo sp. nov. (male) – Sternitogenittal area. Abbreviations: ly = prodorsal lyrifissure, sv = sternal verrucae, pgc = pregenital capsule, pg = pregenital area, g = genital area.