Sayanozercon mikhaili, Marchenko, 2025

Marchenko, Irina I., 2025, The new genus Sayanozercon (Acari: Mesostigmata: Zerconidae) with description of five new species from South Siberia mountains (Russia), Zootaxa 5647 (2), pp. 151-195 : 178-183

publication ID	https://doi.org/10.11646/zootaxa.5647.2.5
publication LSID	lsid:zoobank.org:pub:E7A8B8B7-7066-422B-859C-B3DB4F2F06C7
DOI	https://doi.org/10.5281/zenodo.15819695
persistent identifier	https://treatment.plazi.org/id/038B87E0-B12E-FFF4-6AAD-5399D98291E3
treatment provided by	Plazi
scientific name	Sayanozercon mikhaili
status	sp. nov.

Treatment

Sayanozercon mikhaili sp. nov.

( Figures 46–54 View FIGURE 46 View FIGURE 47–50 View FIGURE 51 View FIGURE 52–54 )

Female ( Figs 46–50 View FIGURE 46 View FIGURE 47–50 , n=10)

Dorsal idiosoma ( Fig. 46 View FIGURE 46 ). Idiosoma rounded-oval shape, 545–565 long, 400–425 wide, without obvious ornamentation, divided into two shields that cover entire dorsal idiosoma.All dorsal setae smooth, pointed. Podonotal shield with 21 pairs of setae, including r1 located in podonotal shield and r3 located in peritrematal shield; seta r3 is 4 times longer than r1. Setae z1 and z2 lost. Seta s1 presented. Length of podonotal setae and opisthonotal setae and longitudinal distances between insertions of opisthonotal setae in specific series female and male summarized in Table 6. Setae j6 shortest in j- series, setae z4 longest in z -series, setae s1 shortest and setae s3 longest in s -series and among all podonotal setae. Seta r1 shortest in r -series and among all podonotal setae. Podonotal shield with three pairs of glands: gdj2 (po1), gdj4 (po2), gdz5 (po3). Location of podonotal glands: gdj2 (po1) close to line connecting insertions of setae j2 and z3, posterior to seta s1; gdj4 (po2) close to line connecting insertions of setae j4 and z4; gdz5 (po3) located on posterior edge of podonotal shield, close to line connecting insertions of setae s5 and z6, which is different from typical location of po 3 in other species of new genus Sayanozercon . Five pairs of lyrifissures: idj1, idj3, idz4, ids4, idj6 presented. Opisthonotal shield with delicate reticulation. Opisthonotum with 21 pairs of setae. J -series with full set of setae, among which J3, J4 and J5 shortest. Microsetae J5 is located directly above medial posterodorsal cavities. Z -series with longest setae Z3, Z4 and Z5, among which Z4 and Z5 extend beyond edge of shield. Setae S3, S4 and S5 longest in S -series, extend beyond edge of shield. Setae of R -series medium length. Opisthonotal shield with four pairs of glands and 13 pairs of lyrifissures located as shown in Fig. 46 View FIGURE 46 : gland gdz6 (Po1) anteromedial to seta Z1; gdZ1 (Po2) anterolateral to seta Z1; gdZ3 (Po3) close to line connecting insertions of setae Z3 and Z4; gdZ4 (Po4) on posterior margin of shield behind insertion of seta S5; lyrifissures: ids6, idS1, idz6, idS4, idZ4, idJ4, idJ5, idJ2, idJ3, doubled idJ1 and doubled idS3. Posterodorsal cavities rounded curvings, all similar size, located at posterior margin of opisthonotal shield.

Ventral idiosoma ( Fig. 47 View FIGURE 47–50 ). Base of tritosternum 35–37 long, 23–25 wide; paired laciniae with three distal branches. Sternal shield 73–75 long at midline, 80–83 wide at level st2 setae; with setae st1–st3 similar in length, 20–25, smooth and pointed; with three pairs of lyrifissures iv1, iv2 and iv3 and one pair of glands gv1. Epiginal shield 125–130 long and 95–105 wide with setae st5 (20–25) on shield and pair of lyrifissures iv5. Large endopodal sclerites between coxae III–IV and small ovate-oblong endopodal sclerites around posterior parts of coxae IV presented. Setae st4 (18–20) located outside or on edge of large endopodal shield. Pair of long exopodal sclerites extends from coxae IV to coxae I, closely adjacent to peritrematal shields and bend to dorsal side anteriorly. Pair of peritrematal shields adjacent to additional latero-ventral shields anteriorly and free at level coxae III–IV. Posterior margin of peritrematal shield truncate at level seta S1 not fused with ventrianal shield; with fibre brush of cuticular structure and with two rounded formations in inguinal region (gvi and ivi). Peritrematal shields with smooth and pointed setae r3; with two lyrifissures ip1, ip2 and gland gp from each side. Peritremes short, 40–43. Latero-ventral shield weakly reticulated, extends from seta r3 to R6. Adgenital sclerites presented, each with 4–5 glands openings gv2. Ventrianal shield 235–245 long, 330–340 wide at level seta Zv2, with 21 smooth, pointed setae; with transversal reticulation from anterior margin to level setae Jv3 and strip of darker cuticle on anterior margin of shield, 20–25 wide. Anterior margin of ventrianal shield with two shortest pairs of setae Jv1 and Zv1 (10–12). Other setae in J - series: Jv2 (17–20), Jv3 (30–33), Jv4 (37–43), Jv5 (55-65); other setae in Z -series: Zv2 (15–17), Zv3 (20–23), Zv4 (20–23); para-anal setae 50-53, post-anal 40–43 long. Pair of glands gv3 located at level of posterior edge of the anus. Five pairs of ventrianal lyrifissures present: ivo1–ivo4 and ivp. Anal opening with two pairs of lyrifissures on each valve. Cribrum presented posteriorly of post-anal setae.

Gnathosoma ( Figs 48–50 View FIGURE 47–50 ). Movable digit of chelicera 60–62 long, with three teeth in addition to apical hook; fixed digit the same length, with five teeth, including offset distal tooth (gabelzhan), and four teeth in masticatory surface in addition to apical hook; leaf-shaped pilus dentilis and apical sensorial depression presented ( Fig. 48 View FIGURE 47–50 ). Chelicera with long dorsal seta, lateral (antiaxial) and dorsal lyrifissures; with smooth arthrodial corona and suboval area (“window”) of thin cuticle on paraxial side. Epistome with irregularly serrated lateral edges, medial ridge and serrated middle process with median row of small spines ( Fig. 49 View FIGURE 47–50 ). Corniculi horn-like, internal malae extending beyond corniculi, with fimbriate lateral margins and smooth pointed apices ( Fig. 50 View FIGURE 47–50 ). Deutosternal groove with seven transverse denticulate rows. Hypostome with four pairs of setae, setae h1–h3 smooth, h1 (37–39) the longest, seta h2 (18–20) shorter than h3 (27–32), pc (25–27) serrated. Palpal chaetotaxy typical for genus Sayanozercon .

Legs. Chaetotaxy of I–IV legs is typical for Zerconidae . Pretarsus of legs II–IV with ambulacral stalk, tarsi I with sessile claws. Coxae II with antero-dorsal spine.

Male. ( Figs 51–54 View FIGURE 51 View FIGURE 52–54 , n=9).

Dorsal idiosoma. ( Fig. 51 View FIGURE 51 ). Dorsal idiosoma pear-shaped, 460–465 long, 325–330 wide. Ornamentation, adenotaxy and poroidotaxy of dorsal shields as in female.Podonotal and opisthonotal chaetotaxy of male as in female. Lengths of podonotal, opisthonotal setae and longitudinal distances between insertions of setae in opisthonotal series of male summarized in Table 6.

Ventral idiosoma. ( Fig. 52 View FIGURE 52–54 ). Tritosterum form as in female. Sternal shield fused with genital shield with area of weak sclerotisation and weak reticulation between setae st1 and st2. Sternigenital shield with area of weak sclerotisation and weak reticulation between setae st1 and st2, 150–153 long with four pairs of setae st1–st4 (15– 17), three pairs of lyrifissures iv1, iv2 and iv5, one pair of glands gv1 and genital opening opposite coxae III, eugenital setae not visible under light microscopy. Peritrematal shields connected posteriorly to each other by fibre brush of cuticular structure; each with short peritrema, with smooth, pointed seta r3, lyrifissures ip1, ip2 and gland gp. Posterior margins of peritrematal shields with two pairs of rounded formations hollow inside (inguinal poroids gvi and ivi). Latero-ventral shields shaped as in female, with weak longitudinal reticulation. Ventrianal shield with weak transversal reticulation, 200–205 long and 275–290 wide; with 19 smooth and pointed setae, setae Zv1 not developed; with five pairs of lyrifissures ivo1–ivo4, ivp and pair of glands gv3. Length of ventrianal setae: Jv1 (17–19), Jv2 (15–18), Jv3 (27–30), Jv4 (35–37), Jv5 (50–53), Zv2– Zv4 (17–20), para-anal setae 43-47, post-anal 32–35 long. Multiple glands gv2 with 4–5 openings located on anterior margin of ventrianal shield. Anal opening with two pairs of lyrifissures on each valve. Cribrum presented posteriorly of post-anal seta.

Gnathosoma ( Figs 53–54 View FIGURE 52–54 ). Movable digit of chelicera 45–47 long, with three teeth in addition to apical hook, fixed digit the same length, with six teeth including offset lateral-distal tooth (gabelzhan), five teeth in masticatory surface, addition to apical hook; leaf-shaped pilus dentilis, apical sensorial depression presented ( Fig. 53 View FIGURE 52–54 ). Male chelicera with dorsal seta, lyrifissures and arthrodial corona as in female. Epistome ( Fig. 54 View FIGURE 52–54 ), corniculi, internal malae and palpal structures as in female.

Legs. Chaetotaxy and morphology of legs as in female.

Juveniles not found.

Material examined. Holotype female, Russia, KRASNOYARSKII KRAI, West Sayan Mt., Ergaki Ridge, 52° 46’ N, 93° 21’ E, 1117–1250 m a.s.l., taiga along Tushkanchik river, Abies sibirica – Pinus sibirica , in moss, 5.VII 2024, leg. I.I. Marchenko. Paratypes: 6 females, 8 males, same geographic and locality data as holotype; 1 male, Ergaki Ridge, 52° 50’ N, 93° 21’ E, 1000 m a.s.l., Abies sibirica forest, in litter and moss, 27. VI 2013, coll. A. Kostyunin; 1 female, Ergaki Ridge, pass Olenya Rechka, 52° 48’ N, 93° 14’ E, 1000 m a.s.l., 1479 m a.s.l., taiga with Abies sibirica – Pinus sibirica , in moss, 20.VII 2018, leg. I.I. Marchenko; KEMEROVO REGION, 1 female, mountain region Gornaya Shoria, environs of Tashtagol City, foot of Mustag Mt., Abies sibirica – Picea obovata – Pinus sibirica forest, 52° 58’ N, 87° 44’ E, 600 m a.s.l., 19. VI 2013, leg. I.I. Marchenko.

Etymology. New species S. mikhaili dedicated to my son Mikhail V. Marchenko for his invaluable assistance in expedition situations.

Remarks. Distinguishing characters of adults of Sayanozercon mikhaili sp. nov. are: large size of idiosoma; setae s1 present on podonotal shield; opisthonotal shield with five short pairs of setae in J -series, among which J3, J4 and J5 are micro setae; setae Z3, Z4, Z5 longest in Z -series, Z3 and Z4 extend beyond the edge of shield; seta S2 shortest in S -series, approach edge of shield; setae S3, S4 and S5 long, extend beyond the edge of opisthonotal shield. Sayanozercon mikhaili sp. nov. differs from all others species of new genus by atypical position of gland gdz5 (po3) located close to posterior edge of podonotal shield, close to line connecting insertions of setae s5 and z6, close. Location of opisthonotal glands: gdz6 (Po1) anteromedial to seta Z1; gdZ1 (Po2) anterolateral to seta Z1. Internal malae with smooth pointed apices; fixed digit of chelicera with sexual dimorphism – five teeth in female versus six teeth in male.