Athyreacarus variabilis Khaustov & Frolov 2019, sp. nov.
Creators: name: Khaustov, Alexander A.
name: Frolov, Andrey V.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Actinedida
Athyreacaridae
Athyreacarus
Athyreacarus variabilis

description: Athyreacarus variabilis sp. nov.
(Figs 15–20)
Description. Female (Figs 15–20). Body broadly fusiform. Length of idiosoma 405 (305–405), width 240 (185– 240).
Gnathosoma. Gnathosomal capsule, excluding palps, almost oval, length 59 (56–60), width 69 (62–69). One pair of barbed, blunt-ended cheliceral setae cha 33 (32–34). Postpalpal setae (pp) 12 (8–12) needle-like. Subcapitular setae m 11 (8–11) smooth, blunt-ended, and n 64 (48–70) barbed, pointed. Setae dFe 16 (13–17) and dGe 35 (24–35) weakly barbed; setae dFe blunt-ended, dGe pointed. Tibiotarsal rodlike eupathid not evident. Tibial claw well-developed, slightly hooked with short basal projection.
Idiosomal dorsum (Figs 15A, 18A, 19A, B, 20 A–C). All dorsal shields with numerous relatively small densely distributed dimples (Figs 19A, B). Hysterosomal shields almost completely covering hysterosoma and only lateral parts with soft cuticle. Prodorsal shield without lateral projections. Prodorsal shield and central shield of tergite C with weak subcuticular reticulation (Figs 19A, B). Setae sc 1 variable in length from vestigial to well-developed, subequal with v 2 (Fig. 20C). Sometimes one or both setae v 2 absent (Figs 20A, B). All dorsal setae weakly barbed. Setae v 2 and e blunt-ended, other dorsal setae pointed. Cupules ia on tergite D, im, ip on tergite EF and ih on tergite H large, round. Cupules ih located dorsally, anterolaterally to bases of setae h 1. Pseudanal segment much shorter than tergite H. Lengths of dorsal setae: v 1 84 (72–95), v 2 27 (19–28), sc 1 8 (0–19), sc 2 150 (130–155), c 1 135 (115–140), c 2 145 (120–150), d 140 (125–155), e 47 (34–48), f 145 (135–150), h 1 110 (93–115), h 2 110 (90–110). Distances between setae: v 1 –v 1 36 (33–36), v 2 –v 2 75 (65–76), sc 1 –sc 1 95 (80–100), sc 2 –sc 2 78 (72–82), c 1 – c 1 70 (61–71), c 1 – c 2 49 (49–51), d–d 85 (74–85), e–e 71 (67–73), f–f 79 (70–84), h 1 – h 1 50 (41–50), h 1 – h 2 23 (17–23).
Idiosomal venter (Figs 15B, 18B, 19C, D, 20D). All ventral plates with numerous small dimples (Figs 19C, D), dimples on aggenital and midsternal plates arranged slightly more densely than on other plates. All ventral setae weakly barbed. Setae 1 b, 2 c, 3 a, 4 c, ag 1, ps 1, ps 3 blunt-ended, other ventral setae pointed. Ap5 short, located near base of legs IV. Aggenital plate with three pairs of aggenital setae. Some specimens with additional unpaired aggenital seta (agx) (Fig. 20D). Anal opening terminal. Length of mid-sternal plate 61 (53–62), width 64 (60–65); ratio length/width 0.9–1.0. Lengths of ventral setae: 1 a 41 (31–43), 1 b 17 (12–18), 1 c 24 (16–26), 2 a 62 (50–63), 2 b 43 (29–44), 2 c 17 (14–18), 3 a 20 (17–21), 3 b 46 (39–47), 3 c 31 (21–32), 4 a 35 (33–47), 4 b 48 (34–50), 4 c 26 (20–31), ag 1 22 (16–24), ag 2 59 (49–64), ag 3 61 (51–68), ps 1 63 (62–75), ps 2 71 (63–76), ps 3 42 (34–46).
Legs (Figs 16, 17). Length of legs: I 135 (120–135), II 145 (115–145), III 150 (125–150), IV 165 (145–165). Leg I (Fig. 16A): setae v’ of femur, k of tibia, s, pv”, and pl’ of tarsus smooth, other leg setae (except eupathidia) weakly barbed; setae l’, l”, v’ of femur, d, v’, l” of genu, and k of tibia blunt-ended; other leg setae (except eupathidia) pointed; lengths of solenidia ω 1 15 (12–15), ω 2 12 (9–12), φ 1 11 (10–12), φ 2 10 (8–10); ω 1 digitiform, φ 1 weakly clavate, ω 2 and φ 2 baculiform. Leg II (Fig. 16B): solenidion ω 13 (12–13) digitiform, solenidion φ 11 (10–11) baculiform; all leg setae weakly barbed; setae l’ of femur and tc” of tarsus blunt-ended, other leg setae pointed; seta tc” of tarsus slightly spatulate distally. Leg III (Fig. 17A) similar in shape and length to leg II; solenidion φ 11 (10–11) baculiform; all leg setae weakly barbed; seta tc” of tarsus blunt-ended, spatulate distally, other leg setae pointed. Leg IV (Fig. 17B): solenidion φ 11 (9–11) baculiform; all leg setae weakly barbed; setae v’ of femur, l” of genu, p’ and tc’ of tarsus blunt-ended, other leg setae pointed; seta tc’ of tarsus weakly spatulate distally.
Type material. Female holotype, slide No. 1736.1, BRASIL, Pernambuco, Recife, Parque Estadual de Dois Irmãos, 14.II.2007, A.C. Mayer leg., on a beetle Neoathyreus cf. anthracinus (Klug). Paratypes: 21 females, same data.
Type deposition. The holotype and five paratypes are deposited in the collection of UNESP — Universidade Estadual Paulista, Department of Zoology and Botany, 15054—000 São José do Rio Preto—SP, Brazil; 10 paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia; six paratypes are deposited in the collection of the Zoological Institute of RAS, Saint Petersburg, Russia.
Differential diagnosis. The new species is very similar to A. magnificus sp. nov. and A. similis sp. nov. by the absence of setae chb, presence of three pairs of aggenital setae, setae sc 1 vestigial, and setae c 1 well developed. The new species differs from A. magnificus and A. similis by its very small, densely distributed dimples on idiosomal plates (vs. large, sparsely distributed dimples on idiosomal plates in A. magnificus and A. similis) and by the presence of weak subcuticular reticulation on prodorsal shield and central part of tergite C (vs absent in A. magnificus and A. similis). The new species differs from A. similis by setae tc” on tarsi II and III and tc’ on tarsus IV spatulate (vs pointed in A. similis), and median ends of apodemes 3 and 4 clearly separated (vs. median ends of apodemes 3 and 4 almost connected in A. similis). The new species differs from A. magnificus by setae (pl) on tarsus I and tc’ on tarsi II and III pointed (vs spatulate in A. magnificus).
Etymology. The name of new species derives from the Latin word “ variabilis ” meaning “ variable ” and refers to the unusual high intraspecific variability among idiosomal setae in the new species.
description: Published as part of Khaustov, Alexander A. & Frolov, Andrey V., 2019, Revision of the genus Athyreacarus (Acari: Athyreacaridae), pp. 168-225 in Zootaxa 4647 (1) on pages 184-188, DOI: 10.11646/zootaxa.4647.1.14, http://zenodo.org/record/3352927