Sphaerozetes parafirthensis Ermilov, 2022

ErmilovK, Sergey G., Khaustov K, Alexander A., JoharchiK, Omid, K, Ismail Döker & KhaustovK, Vladimir A., 2022, New faunistical data on oribatid mites (Acari, Oribatida) from Altai, Russia, with description of a new species of Sphaerozetes (Ceratozetidae), Acarologia 62 (4), pp. 1098-1110 : 1104-1108

Sphaerozetes parafirthensis Ermilov n. sp.

Zoobank: 1A025B01-E8ED-4748-BAE2-B053D27073C1 ( Figures 1 , 2 )

Diagnosis — Body length: 575–600. Rostrum bidentate. Lamellar cusp about 1/3 of lamella, with strong lateral tooth. Translamella comparatively broad. Rostral, lamellar and interlamellar setae long, setiform, barbed; ro shortest, in longest; bothridial seta medium-sized, narrowly lanceolate, barbed. Notogastral porose areas rounded or slightly oval, punctiform. Eleven pairs of notogastral setae setiform, thin, smooth; c 3 longest. Epimeral and anogenital setae short, setiform, thin, barbed. Postanal porose area oval. No thick seta on leg tibiae and genua.

Description of adult — Measurements – Body length: 570 (holotype, female), 575–600

(10 paratypes, three males and seven females); body width: 375 (holotype), 375–390 (10 paratypes). No difference between males and females in body size.

Integument – Body colour brown. Body surface microsculpturing tuberculate (visible in dissected specimens under 10 × 100 magnification). Lamella and tutorium partially striate. Antiaxial side of femora I–IV with slight tubercles.

Prodorsum – Rostrum bidentate, lateral teeth well developed. Lamella (including cusp) about 1/2 length of prodorsum; cusp about 1/2 of lamella, with strong lateral tooth. Translamella distinct, comparatively broad. Tutorium (including cusp) about 4/5 length of prodorsum; cusp lamelliform. Porose area Al not observed. Genal tooth elongate triangular. Rostral (67–71), lamellar (94–101) and interlamellar (116–124) setae setiform, barbed; basal part of ro covered by tutorial cusp in lateral aspect. Bothridial seta (64–70) narrowly lanceolate, barbed; stalk slightly shorter than head. Opening of bothridium not covered by anterior margin of notogaster in dorsal aspect. Exobothridial seta (28–30) setiform, thin, barbed. Dorsosejugal porose area oval, poorly visible. Dorsophragmata clearly separated medially.

Notogaster – Lenticulus present, diffuse. Pteromorph broadly rounded laterally. Four pairs of porose areas; Aa (15–19; 17–19 × 13–15) and A1 (11–13; 15–19 × 13) rounded or slightly oval, A2 (11–13) and A3 (13–15) rounded, all punctiform (without distinct borders), slightly bordered. Eleven pairs of notogastral setae developed c 3: (30–37; c 2: 22–26; others: 11–15),

all setiform, thin, smooth. Opisthonotal gland opening and lyrifissures ia,(im, ip, ih, ips) distinct.

Gnathosoma – Subcapitulum size: 135–150 × 94–105; subcapitular (a: 22–26; m: 37–41;

h: 34–37) and adoral (17–19) setae setiform, barbed. Palp (105–112) setation: 0-2-1-3-9(+ω); postpalpal seta (9) thorn-like, roughened. Chelicera (135–150) with two setiform, barbed setae (cha: 45–49; chb: 34–36).

Epimeral and lateral podosomal regions – Epimeral setal formula: 3-1-3-3. Epimeral setae

(1a, 2a, 3a: 26–37; 4c: 17–19; others: 41–49) setiform, thin, barbed. Humeral porose areas Am and Ah oval, poorly visible. Custodium short, narrowly triangular. Discidium broadly triangular. Circumpedal carina long, apically fused to custodium. Horizontal folds in integument absent between and dorsal of acetabula II and III.

Anogenital region – Six pairs of genital, one pair of aggenital, two pairs of anal, and three pairs of adanal setae (17–19) setiform, thin, barbed. Adanal lyrifissure located close and slightly diagonal to anterior half of anal plate. Postanal porose area (26–30 × 11–15) oval.

Legs – Median claw distinctly thicker than lateral claws, all slightly barbed dorsally. Dorsoparaxial porose area on femora I–IV and on trochanters III, IV distinct; proximoventral porose area on tarsi I–IV and distoventral porose area on tibiae I–IV not observed. Genua I–IV without lateral tubercle and ventral triangular process. Formulas of leg setation and solenidia: I (1-5-3-4-20) [1-2-2], II (1-5-3-4-16) [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 as indicated in Table 1. Famulus short, slightly swollen distally, inserted between solenidia 1 ωand ω 2 ; seta s on tarsus I eupathidial, located between paired setae u and a.; lateral antiaxial seta (l″ on legs I, II; l′ on legs III, IV) on all tibiae and genua setiform or slightly thickened (but not thick). Solenidia 1 and ω ω 2 on tarsus II and σ on genu III slightly bacilliform, other solenidia setiform; dorsodistal tubercle of tibia I absent.

Material examined — Holotype (female) and 10 paratypes (three males and seven females): Russia, Altai Republic, Kosh-Agachsky District , mountain steppe, soil and moss, 14.06.22, 49°42′40.0″N 88°25′15.3″E, 2230 m a.s.l. (leg. A.A. Khaustov, O. Joharchi, I. Döker, V. A. Khaustov, and R. V. Latyntsev).

Type deposition — The holotype is deposited in the collection of the Senckenberg Museum of Natural History, Görlitz, Germany ; 10 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.

Etymology — The name parafirthensis refers to the similarity between new species and Sphaerozetes firthensis Behan-Pelletier, 1986 .

Remarks — In having 11 pairs of short, setiform notogastral setae with longest c 3, and well-developed lamellar cusp (1/2 of lamella) Sphaerozetes parafirthensis Ermilov n. sp. is similar to Sphaerozetes firthensis Behan-Pelletier, 1986 from Canada (see Behan-Pelletier

1986). However, the new species differs from the latter by the larger body size (length: 575– 600 versus 473–518), narrowly lanceolate bothridial seta (versus clavate or fusiform, with large head), strong lateral tooth on lamellar cusp (versus slightly observed), and broadly oval (versus narrowly elongate oval) postanal porose area.

Distinctive characters of the new species from the other Sphaerozetes species in the Palaearctic region can be found in the identification key below.

Figures

Figure 1 Sphaerozetes parafirthensisErmilov n. sp., adult: a – dorsal view (legs omitted); b – medioanterior part of prodorsum, dorsoanterior view; c – ventral view (gnathosoma and legs omitted); d – right lateral view (gnathosoma and legs omitted); e – posterior view (right half omitted). Scale bars 100 μm (a, c–e), 50 μm (b).

Figure 2 Sphaerozetes parafirthensisErmilov n. sp., adult: a – subcapitulum, ventral view; b – palp, right, antiaxial view; c – chelicera, left, paraxial view; d – leg I, right, antiaxial view; e – leg II, right, antiaxial view (tarsus omitted); f – leg III, right, antiaxial view (tarsus omitted); g – leg IV, left, antiaxial view. Scale bars 100 μm (a, c–g), 10 μm (b).