Sayanozercon shoricus, 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 : 183-189

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.15819699
persistent identifier	https://treatment.plazi.org/id/038B87E0-B115-FFF2-6AAD-5556DC8E97C4
treatment provided by	Plazi
scientific name	Sayanozercon shoricus
status	sp. nov.

Treatment

Sayanozercon shoricus sp. nov.

( Figures 55–61 View FIGURE 55 View FIGURE 56–58 View FIGURE 59 View FIGURE 60–61 )

Female ( Figs 55–58 View FIGURE 55 View FIGURE 56–58 , n=2)

Dorsal idiosoma ( Fig. 55 View FIGURE 55 ). Idiosoma oval shape, 445–450 long, 315–330 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 seta located in peritrematal shield; seta r3 is 4 times longer than r1. Setae z1 and z2 lost. Length of podonotal setae, opisthonotal setae and longitudinal distances between insertions of opisthonotal setae in specific series female and male summarized in Table 7. Setae in j- series similar in length; setae s1 shortest, setae z4 longest in z -series; 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) which are located in typical positions for most species of genus Sayanozercon . Location of podonotal glands: gdj2 (po1) close to line connecting insertions of setae j2 and z3, posrerior to insertion of seta s1; gdj4 (po2) close to line connecting insertions of setae j4 and z4; gdz5 (po3) close and anterior to line connecting insertions of setae z5 and s5. Five pairs of podonotal lyrifissures: idj1, idj3, idz4, ids4, idj6 presented. Opisthonotal shield with delicate reticulation. Opisthonotal shield with 21 pairs of setae. Setae of J -series with full set, among which J3, J4 and J5 microsetae. Setae 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 extend beyond edge of shield, among them setae S4 and S5 longest in S -series. Setae of R -series all long. Opisthonotal shield with four pairs of glands and 13 pairs of lyrifissures. Location of opisthonotal glands: gdz6 (Po1) anteromedial to seta Z1; gdZ1 (Po2) on line connecting insertions of setae Z1 and Z2; gdZ3 (Po3) close to line connecting insertions of setae Z3 and Z4; gdZ4 (Po4) on posterior margin of shield behind insertion of seta S5. Location of lyrifissures shown in Fig. 55 View FIGURE 55 : ds6, 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. 56 View FIGURE 56–58 ). Base of tritosternum 25–27 long, 18–20 wide; paired laciniae with three distal branches. Sternal shield 63–65 long at midline, 67–70 wide at level st2 setae; with setae st1–st3 similar in length, 17–19, smooth and pointed; with three pairs of lyrifissures iv1, iv2 and iv3 and one pair of glands gv1. Epiginal shield 100–107 long and 65–67 wide with setae st5 (17–19) 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 (15–17) located outside 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. Peritrematal shield truncate at posterior margin, not fused with ventrianal shield; with fibre brush of cuticular structure and with two rounded formations in inguinal region (gland gvi and lyrifissure ivi) from each side. Peritrematal shields with smooth and pointed setae r3; two lyrifissures ip1, ip2 and gland gp from each side. Peritremes short, 35–37. Pair of latero-ventral shields weakly longitudinal reticulated, extends from seta r3 to R6. Adgenital sclerites presented each with 4 glands openings gv2. Ventrianal shield 187–190 long, 245–255 wide at level seta Zv2, with 21 smooth, pointed setae; with narrow strip of transversal reticulation Anterior margin of ventrianal shield with two shortest pairs of setae Jv1 and Zv1 (8–10). Other setae in J -series: Jv2 (15–17), Jv3 (28–30), Jv4 (37–39), Jv5 (50–52); other setae in Z -series: Zv2 (13–15), Zv3 (18–20), Zv4 (10–12); para-anal setae 50–53, post-anal 33–35 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 57–58 View FIGURE 56–58 ). Movable digit of chelicera 48–50 long, with three teeth in addition to apical hook, fixed digit the same length, with five teeth, including offset lateral-distal tooth (gabelzhan), followed by four teeth in masticatory surface in addition to apical hook; pilus dentilis, dorsal seta, cheliceral lyrifissures and arthrodial corona not visible ( Fig. 57 View FIGURE 56–58 ). Epistome with irregularly serrated lateral edges, with medial ridge and serrated middle process, with median row of small spines ( Fig. 58 View FIGURE 56–58 ). Corniculi horn-like, internal malae extending beyond corniculi, with fimbriate lateral margins and bifurcate apices ( Fig. 57 View FIGURE 56–58 ). Deutosternal groove with seven transverse denticulate rows. Hypostome with four pairs of setae, setae h1–h3 smooth, h1 (37–39) the longest, seta h2 (15–16) shorter than h3 (25–26), pc (25–27) serrated. Palpal chaetotaxy typical for genus Sayanozercon .

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

Male. ( Figs 59–61 View FIGURE 59 View FIGURE 60–61 , n=2).

Dorsal idiosoma. ( Fig. 59 View FIGURE 59 ). Dorsal idiosoma oval-shaped, 365–375 long, 245–260 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 7.

Ventral idiosoma. ( Fig. 60 View FIGURE 60–61 ). 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, 137–140 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 (32–33), smooth and 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 without ornamentation, 155–157 long and 220–225 wide; with 19 smooth and pointed setae, setae Zv1 lost; with five pairs of lyrifissures ivo1–ivo4, ivp and pair of glands gv3. Length of ventrianal setae: Jv1 (10–12), Jv2 (12–15), Jv3 (23–25), Jv4 (30–32), Jv5 (47–50), Zv2 (10–12), Zv3– Zv4 (13–15), para-anal setae 47–50, post-anal 30–32 long. Multiple glands gv2 with 4 openings located on anterior margin of ventrianal shield. Anal opening with two lyrifissures on each valve. Cribrum presented posteriorly of post-anal seta.

Gnathosoma . Movable digit of chelicera 37–39 long, with three teeth in addition to apical hook, fixed digit the same length, with offset lateral-distal tooth (gabelzhan), number of other teeth, dorsal seta, lyrifissures and arthrodial corona are not clearly distinguished. Epistome ( Fig. 61 View FIGURE 60–61 ), 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, KEMEROVO REGION, Gornaya Shoria mountain massif, Mrassu river valley, environs of Kabyrza village , 52° 50’ N, 88° 47’ E, 460 m a.s.l., under Pinus sylvestris , in litter, 18.VIII 2015, coll. L.A. Trilikauskas. GoogleMaps Paratypes: 1 female, same geographic and locality data as holotype GoogleMaps ; 2 males, KEMEROVO REGION, environs of Mezhdurechensk City , 53° 41’ N, 88° 06’ E, 425 m a.s.l., under Calamagrostis sp. , in litter, 28.V 1981, coll. V. V. Nikolskii GoogleMaps .

Etymology. New species S. shoricus is named after Gornaya Shoria mountain massif in Kemerovo Region in southern Siberia of Russia, where the type material of this species was found.

Remarks. Distinguishing characters of adults of Sayanozercon shoricus sp. nov. are: mid-size of idiosoma; seta s1 present on podonotal shield; podonotal gland gdz5 (po3) located close and anterior to line connecting insertions of setae z5 and s5; opisthonotal gland gdZ1 (Po2) located on line connecting insertions of setae Z1 and Z2, what differs from four others species of new genus Sayanozercon . Opisthonotal shield with five short pairs of setae in J -series, among which J3, J4 and J5 are microsetae; setae Z3, Z4, Z5 longest in Z -series, Z3 approach edge of shield and Z4 extend beyond the edge of shield; setae S1, S2 shortest in S -series, S2 approach edge of shield; setae S3, S4 and S5 long, extend beyond edge of opisthonotal shield. Internal malae with bifurcate apices.