Зоологический журнал, 2023, T. 102, № 3, стр. 243-250

MATERIALS AND METHODS

S p e c i m e n s. Samples of bark were collected via climbing trees (using spikes and other special equipment) and removing outer bark. Mites were subsequently extracted by high-pressure flushing and further heptane flotation under laboratory conditions. Detailed descriptions of arboreal acarofauna collection and extraction techniques are presented in Salavatulin (2019).

O b s e r v a t i o n  a n d  d o c u m e n t a t i o n. Specimens were mounted in lactic acid on temporary cavity slides for the identification of all taxa, as well as measurement and illustration of the new species. Body length was measured in lateral view, from the tip of the rostrum to the posterior edge of the notogaster. Notogastral width refers to the maximum width of notogaster in dorsal view. Lengths of body setae were measured in lateral aspect. All body measurements are presented in micrometers. Formulas for leg setation are given in parentheses according to the sequence trochanter–femur–genu–tibia–tarsus (famulus included). Formulas for leg solenidia are given in square brackets according to the sequence genu–tibia–tarsus. Drawings were made with a camera lucida using a Leica transmission light microscope “Leica DM 2500”.

T e r m i n o l o g y  a n d  c o n v e n t i o n s. Morphological terminology used in this paper mostly follows that of F. Grandjean: see Travé and Vachon (1975) for references; Norton (1977) for leg setal nomenclature; Mahunka and Zombori (1985) for body setal nomenclature; and Norton and Behan-Pelletier (2009) for overview.

A b b r e v i a t i o n s  a n d  n o t a t i o n s. Prodorsum: cos – costula; tcos – transcostula; tu – tutorial carina; ro, le, in, bs, ex – rostral, lamellar, interlamellar, bothridial, and exobothridial seta, respectively; co.pm, co.pl – medial and lateral prodorsal condyle, respectively. Notogaster: co. nm, co.nl – medial and lateral notogastral condyle, respectively; c, la, lm, lp, h, p – setae; ia, im, ip, ih, ips – lyrifissures; gla – opisthonotal gland opening. Gnathosoma: a, m, h = subcapitular setae; or = = adoral seta; ω = palp solenidion; cha, chb = cheliceral setae; Tg = Trägårdh’s organ. Epimeral and lateral podosomal regions: 1a, 1b, 1c, 2a, 3a, 3c, 4a, 4b, 4c = epimeral setae; z = aperture of supracoxal gland; Pd I, Pd II – pedotectum I, II, respectively. Anogenital region: g, ag, ad, an – genital, aggenital, adanal, and anal seta, respectively; iag, iad – aggenital and adanal lyrifissure, respectively. Legs: Tr, Fe, Ge, Ti, Ta = = trochanter, femur, genu, tibia, and tarsus, respectively; ω, φ, σ = solenidia; ɛ = famulus; v, ev, bv, l, d, ft, tc, it, p, u, a, s, pv – setae.

Pseudotocepheus cattienensis Ermilov et Salavatulin sp. n.

(Figs 1–3)

Fig. 1.

Pseudotocepheus cattienensis sp. n., adult: a – dorsal view, b – ventral view (gnathosoma and legs not shown). Scale bar 100 µm.

Fig. 2.

Pseudotocepheus cattienensis sp. n., adult: a – right lateral view (legs not shown); b – subcapitulum, ventral view; c – palp, left, paraxial view; d – chelicera, left, paraxial view. Scale bar (μm): a – 100; b–d – 20.

Fig. 3.

Pseudotocepheus cattienensis sp. n., adult: a – leg I, right, antiaxial view, b – leg II, without tarsus, right, antiaxial view, c – leg III, without tarsus, left, antiaxial view; d – leg IV, left, antiaxial view. Scale bar 50 µm.

T y p e  m a t e r i a l. Holotype (♀) and two paratypes (1♂, 1♀): Vietnam, Dong Nai Province, Dong Nai Biosphere Reserve, Cat Tien National Park, 11°26′30′′ N, 107°25′56′′ E, about 130 m a.s.l., bark of the Dipterocarpus alatus tree at the height of 25.5 m (sample 13-3), 20.06.2021–04.07.2021 (collected by V.M. Salavatulin and A.A. Kudrin).

The holotype and paratypes are deposited in the Tyumen State University Museum of Zoology, Tyumen, Russia. All specimens are preserved in ethanol with a drop of glycerol.

D i a g n o s i s. Body length: 540–645. Dorsal side of prodorsum with large, dense foveolae; notogaster and anogenital region with small, sparse, poorly visible foveolae; posterior part of notogaster densely tuberculate. Costula reaching insertion of lamellar seta. Transcostula present. Rostral seta setiform, barbed; lamellar, interlamellar and notogastral setae thickened, erect, mediodistally heavily shortly ciliate (and indistinctly bushed); interlamellar seta distinctly removed from bothridium. Two pairs of medial prodorsal condyles present; medial notogastral condyles present but poorly developed. All genital setae needleform; aggenital setae filiform, slightly roughened; adanal and anal setae filiform, erect, slightly barbed; ad₃ located in preanal position. Adanal lyrifissure oblique. Leg setae u on all tarsi filiform (not thorn-like).

D e s c r i p t i o n. Measurements. Body length: 645 (holotype), 540 (paratype, male), 645 (paratype, female); notogaster width: 285 (holotype), 225 (paratype, male), 300 (paratype, female). Body length/width ratio: 2.1–2.4.

Integument. Body color light brown, but all legs, genital plates, subcapitular genae and rutelli, and distal part of chelicerae dark brown. Body surface microgranulate (well visible under high magnification, 10 × 100); dorsal side of prodorsum (between costulae) and lateral part of epimeres I, II with large, dense foveolae (diameter up to 11); notogaster (except posterior part), anogenital region, subcapitular mentum, and lateral side of prodorsum with small, sparse, poorly visible foveolae (diameter up to 7); posterior part of notogaster and lateral part of body (between bothridium and acetabula II, III) with dense tubercles (diameter up to 11).

Prodorsum. Rostrum broadly rounded. Costula long, reaching insertion of lamellar seta but slightly developed mediodistally. Transcostula lineate, convex medially. Tutorial carina present, short, poorly observed. Rostral seta (79–90) setiform, barbed, curving and directed anteromedially. Lamellar (79–90) and interlamellar (56–71) setae thickened, erect, mediodistally heavily shortly ciliate (and indistinctly bushed); interlamellar seta distinctly distant from bothridium. Exobothridial seta (4) needleform. Bothridial seta (their length out of bothridium: 64–67) fusiform, slightly barbed. One pair of lateral and two pairs of medial prodorsal condyles simple, tubercle-like; medial condyles connected mediobasally; medial and lateral condyles located separately.

Notogaster. One pair of lateral and one pair of medial notogastral condyles simple, tubercle-like; medial condyles poorly developed. All notogastral setae (49–64) thickened, erect, mediodistally heavily shortly ciliate (and indistinctly bushed). All lyrifissures and opisthonotal gland opening distinct; ia located posterolateral to seta c; gla anterior to im.

Gnathosoma. Subcapitulum size: 120–135 × 86–90; subcapitular setae (a: 22–26; m, h: 37–45) filiform, slightly barbed. Palp (length: 64–67) with setation 0–2–1–3–8(+ω); postpalpal seta (7) spiniform, slightly roughened. Chelicera length: 120–135; cheliceral setae (cha: 37–41; chb: 19–22) filiform, barbed.

Epimeral and lateral podosomal regions. Apodemes I, II, III and sejugal apodeme well developed. Epimeral setal formula: 3–1–3–3; setae 1a, 2a, 4b (15–19) needleform; 1b, 3b (49–52), 3a, 4a (26–30) filiform, slightly roughened; 1c (49–52) filiform, slightly barbed; 3c, 4c (22) filiform, erect, slightly barbed. Pedotectum I represented by small lamina. Discidia triangular, round distally.

Anogenital region. Aggenital lyrifissure located lateral to genital aperture. All genital setae (11–15) needleform; aggenital setae (30–34) filiform, slightly roughened; adanal (ad₁, ad₂: 45–52; ad₃: 34–37) and anal (an₁: 22; an₂: 26–30) setae filiform, erect, slightly barbed; ad₃ located in preanal position, distance ad₃–ad₃ shorter than ad₂–ad₂; distance an₁–an₁ shorter than an₂–an₂. Adanal lyrifissure oblique, located lateral to anal plate and slightly distanced from it.

Legs. Claw of all leg strong, slightly barbed on dorsal side. Dorsal side of tarsi I–IV without teeth. Dorsoparaxial porose area on femora I–IV well developed versus not observed on trochanters III, IV. Formulas of leg setation and solenidia: I (1–4–3–4–16) [1–2–2], II (1–4–3–3–15) [1–1–2], III (2–3–0–2–15) [1–1–0], IV (1–2–1–2–15) [0–1–0]; homology of setae and solenidia indicated in Table 1. Solenidia φ₁ on tibia I and φ on tibia II setiform; ω₂ on tarsus II filiform; other solenidia slightly bacilliform. Famulus short, erect, swollen and truncate distally, inserted between solenidion ω₁ and seta ft''. Setae u on all tarsi filiform (not thorn-like). Distal setae of tarsi I–IV (e.g., p except leg I; ft on leg IV; and it, tc, u, a) swollen distally.

Table 1.  

Leg setation and solenidia of adult Pseudotocepheus cattienensis sp. n.

Leg	Tr	Fe	Ge	Ti	Ta
I	v'	d, (l), bv''	(l), v', σ	(l), (v), φ1, φ2	(ft), (tc), (it), (p), (u), (a), s, (pv), ε, ω1, ω2
II	v'	d, (l), bv''	(l), v', σ	l ', (v), φ	(ft), (tc), (it), (p), (u), (a), s, (pv), ω1, ω2
III	v', l '	d, l ', ev'	σ	(v), φ	(ft), (tc), (it), (p), (u), (a), s, (pv)
IV	v'	d, ev'	d	(v), φ	ft'', (tc), (it), (p), (u), (a), s, (pv)

Roman letters refer to normal setae, Greek letters – to solenidia (except ε = 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.

C o m p a r i s o n. Pseudotocepheus cattienensis sp. n. is morphologically most similar to P. setiger Hammer, 1972 in having: large and dense foveolae on the prodorsum; small and sparse foveolae on the notogaster; all prodorsal and notogastral condyles; and medium-sized, thickened, erect, mediodistally heavily shortly ciliate (and indistinctly bushed) lamellar, interlamellar and notogastral setae. However, the new species differs from the latter in: smaller body size (length: 540–645 versus 730); fusiform, narrowed distally (versus clavate, rounded distally) bothridial seta; two pairs (versus one pair) of medial prodorsal condyles; poorly developed (versus well developed) medial notogastral condyles; localization of lamellar seta (distinctly distant from bothridium versus located close to bothridium); tuberculate (versus not tuberculate) posterior part of notogaster; and setiform (versus dilated mediodistally) seta d on leg femora I, II.

E t y m o l o g y. The specific name cattienensis refers to the place of origin, Cat Tien National Park.

GENERAL REMARKS

Species of the family Otocepheidae prefer to live mainly in forest soil-litter, as well as in various ground substrates (e.g., Aoki, 1967; Corpuz-Raros, Ermilov, 2019, 2020). Some otocepheids (for example, Fissicepheus curvisetosus Kubota, 2001) are considered arboreal dwellers (Kubota, 2001). We assume that P. cattienensis sp. n. is a representative of arboreal fauna because 1) it was collected from tree bark at the height of 25.5 m, and 2) it has not been registered in the Cat Tien National Park previously, where soil-litter mite fauna has been sufficiently well studied (Ermilov, 2015). However, our assumption is preliminary and requires confirmation because 1) all three specimens of this species were recovered from the same tree, and 2) despite the height of the collection locale, it is possible that the new species migrated along the tree trunk from soil-litter, which is known for some species of Otocepheidae, e.g., Fissicepheus coronarius Aoki 1967; Pseudotocepheus pauliensis Pérez-Íñigo, Baggio 1993; Pseudotocepheus sp. (Aoki, 1967; Proctor et al., 2002; Karasawa, Hijii, 2008; Accattoli et al., 2013).

KEY TO KNOWN SPECIES OF PSEUDOTOCEPHEUS FROM THE ORIENTAL REGION

1 Three or four pairs of slightly developed medial prodorsal condyles or thickenings instead them; medial and lateral notogastral condyles not developed; all notogastral setae flagellate; adanal lyrifissure transverse or inverse oblique to anal plate; body length: 632–781 ………………………….. P. amonstruosus Mahunka 1973 (=P. septemtuberculatus Balogh, Mahunka 1978; =P. simplex Pérez-Íñigo, Baggio 1980; =P. transversalis Mahunka 1978) [see Mahunka, 1973, 1978; Balogh, Mahunka, 1978; Pérez-Íñigo, Baggio, 1980]. Distribution: Afrotropical and Neotropical regions, Sri Lanka

– One or two pairs of well developed medial prodorsal condyles; medial and lateral notogastral condyles developed; notogastral setae setiform or rod-like, or thickened; adanal lyrifissure oblique or parallel to anal plate …………………………………………... 2

2 Two pairs of medial prodorsal condyles ………… 3

– One pair of medial prodorsal condyles …….….. 4

3 Lamellar, interlamellar and notogastral setae thickened, mediodistally heavily shortly ciliate (and indistinctly bushed); medial notogastral condyles poorly developed; notogastral foveolae small versus dorsal prodorsal foveolae large; posterior part of notogaster tuberculate; body length: 540–645 ............. P. cattienensis sp. n. Distribution: Vietnam

– Lamellar, interlamellar and notogastral setae rod-like, barbed; medial notogastral condyles well developed; notogastral and dorsal prodorsal foveolae large; posterior part of notogaster not tuberculate; body length: 602–823 …. P. mahunkai (Pérez-Íñigo, Baggio 1980) (=P. longus Mahunka 1973) [see Mahunka, 1973; Pérez-Íñigo, Baggio, 1980]. Distribution: Sri Lanka

4 All notogastral setae medium-sized (lm not reaching insertion of lp), thickened; adanal seta ad₃ in preanal position, distance ad₃–ad₃ shorter than ad₂–ad₂ …....... 5

– All notogastral setae long (lm extending anteriorly beyond insertion lp), rod-like or setiform; adanal seta ad₃ in adanal position, distance ad₃–ad₃ longer than ad₂–ad₂ ……………………………………………………….. 6

5 Bothridial seta clavate, rounded distally; lamellar, interlamellar and notogastral setae mediodistally heavily shortly ciliate (and indistinctly bushed); body length: 730 ……………………….. P. setiger Hammer 1972 [see Hammer, 1972]. Distribution: Tahiti, Congo, Vietnam

– Bothridial seta fusiform, narrowed distally; lamellar, interlamellar, and notogastral setae barbed; body length: 703–709 …………………… P. hammerae Chakrabarti, Kundu 1978 [see Chakrabarti et al., 1978]. Distribution: India

6 Bothridial seta bacilliform; notogastral seta p₁ comparatively long, setiform versus other notogastral setae medium-sized, rod-like; body length: 1020–1135 …………………………………. P. contractus Grobler 1997 [see Grobler, 1997]. Distribution: South Africa, India

– Bothridial seta fusiform, narrowed distally; all notogastral setae long, setiform …….....................…. 7

7 Costula reaching insertion of lamellar seta but not extending anteriorly beyond of it; transcostula present; medial prodorsal condyles separated; adanal lyrifissure oblique to anal plate; body length: 1000–1018 ………………........ P. gobletus Chakrabarti, Mondal 1978 [see Chakrabarti et al., 1978]. Distribution: India

– Costula extending anteriorly beyond insertion of lamellar seta; transcostula absent; medial prodorsal condyles connected basally; adanal lyrifissure parallel to anal plate; body length: 850–958 ………………………………………… P. orientalis Mondal, Kundu 1984 [see Mondal, Kundu, 1984]. Distribution: Oriental region.