Halozercon kazachok, Marchenko, 2019

Marchenko, Irina I., 2019, Three new species of Halozercon (Acari: Mesostigmata: Zerconidae) from Altai Mountains in South Siberia (Russia), Zootaxa 4568 (3), pp. 401-434 : 409-420

Halozercon kazachok sp. n.

urn:lsid:zoobank.org:act:FCCF36F1-C26F-4A2C-B32D-4C8E58C9B944

Diagnosis. Vertex with two pairs of setae: j1, z1 and pair of ip1 glands, inserted very close to j1 and z1 setae anteriorly. Podonotum ornamented by small tubercles over the entire surface; median region with sclerotised rounded thickening between po 3 glands. All dorsal setae long, pilose, slightly curved. Median region of opisthonotal shield with 25–27 setae of J series, ornamented by tubercles network. First sternal shield divided in pair of platelets with pair of lyrifissures iv2. Metapodal shields absent. Soft cuticle between genital and ventri-anal shields with pair of setae Jv1. Adult peritremes shorter, than in deutonymph, reaching anterior level of coxae III. Deutotonymph peritremes reaching top of spine of coxae II. Ventri-anal shield with deep incisions from outer margins of shield to level of posterior edge of anal opening. Adult chelicera without sexual dimorphism.

Description. Female ( Figs 48–55 , 66–73 and 75–80 , n=10)

Dorsal idiosoma ( Figs 48 , 66 , 75–76 ). Idiosoma suboval, 500–525 long and 345–380 wide. Anterior margin of the podonotum curved ventrally to form a vertex; with two pairs of setae at arisen bases: j1 (20–22) stout, slightly pilose and z1 smooth (10–12); with pair of ip1 glands, inserted very close to j1 and z1 setae. Podonotal shield strongly neotrichous, with about 83–86 setae on each side, including marginal r setae; with four pairs of pore-like structures (glands) po1–po4. Podonotum ornamented with small tubercles over the entire surface of the shield; median region with sclerotised rounded thickening between po-3 glands. All podonotal setae pilose, slightly curved, 22–25 long. Opisthonotal shield ornamented by network of tubercles over the entire surface, with 58–60 setae on each side, including marginal R setae, all setae long, pilose, slightly curved; with four pairs of pore-like structures (glands) Po1–Po4 ( Fig. 76 ). Median region neotrichous, with 25–27 setae of J series, arrangement asymmetrically, 30–35 long. Setae of Z, S series inserted closely in lateral regions, asymmetrically, neotrichous, 30–37 long. All dorsal setae surrounded by enlarged basal rings. Marginal dorsal setae of r–R series neotrichous, inserted on high tubercles, elongated, 35–37 long.

Ventral idiosoma. ( Figs 49–50 , 67–72 and 77–80 ). Base of tritosternum 25–30 long and 15–17 wide, pilose laciniae free from each other along entire length, 55–60 long ( Fig. 49 ). Presternal (jugular) platelets irregular shape, weakly sclerotised, with pair of St1 (20–23) setae. First sternal shield divided in two suboval platelets, 30– 33 long and 18–23 wide, with pair of St2 setae (18–20) and pair of lyrifissures iv2; with a folded surface ( Figs 49 , 68–70 , 77–80 ). Median area around first sternal platelets ornamented by rounded tubercles. Second sternal shield divided in pair of suboval platelets, 25–30 long, 15–17 wide, with two pairs of setae St3, St4 (15–17) or in some specimens St4 seta inserted in soft cuticle; with two pairs of lyrifissures iv3, iv4. Genital shield 62–70 long, 30–48 wide, irregularly-shaped, with individual shape in each specimen; expanded anteriorly and posteriorly; anterior margin with fine folding; with genital setae St5 (13–15) and lyrifissures iv5 on genital shield or in soft cuticle, laterad of shield ( Fig. 50 ). Subtriangular membrane surrounds the genital shield. Genital shield with complex formation, including one median unpaired cap and two pairs of fine sclerites. Endo-, exopodal and metapodal shields absent. Adgenital gland pores gv2 are multiple, dispersed over the surface: 1–2 glands openings located in soft cuticle postero-laterad of genital shield, another three to five openings located in ventri-anal shield. Soft cuticle between genital and ventri-anal shields with pair of setae Jv1. Peritrematal shields fused anteriorly forming a vertex and fused with dorsal shield laterally; strongly sclerotised, postero-lateral ends are drawn back; ornamented with festoon reticulation along entire length. Five pairs of pore-like structures inserted in peritrematal shield: gp1, gp2 and ip1–ip3. Peritremes straight or slightly curved, short, 90–102 long, reaching anterior level of coxae III; with internal cell structure. Ventri-anal shield broad, 138–148 long and 275–285 wide, fused to opisthonotal shield or with deep incisions from outer margins of shield to level of posterior edge of anal opening; with festoon reticulation, with 8–9 pairs of smooth opisthogastric setae (13–15) inserted anteriorly of incisions. Opisthonotal shield curved on ventral side, with about 15 pilose setae (27–30), inserted posteriorly of incisions; with pair of Po 4 glands and the most posterior row of smooth setae. Anal area with pilose para-anal and smooth post-anal setae (15– 17); anal opening 30–33 long; with two lyrifissure on each valve; cribrum located posteriorly of post-anal seta. Pair of glands gv3 located antero-laterad of para-anal setae.

Gnathosoma . ( Figs 51–55 , 73 ). Fixed digit of chelicera 5 0–55 long, with five teeth in addition to apical hook and leaf-shaped pilus dentilis ( Fig. 51 ); movable digit the same length with three teeth in additional to apical hook. Chelicera with long dorsal seta (18–20), lateral (antiaxial) and dorsal (paraxial) lyrifissures; with arthrodial corona. Epistome subtriangular, with irregularly serrated edges and smooth pointed median projection ( Fig. 52 ). Corniculi 29–30 long and 13–15 wide. Internal malae slightly longer than corniculi, with complex three-layer structure as in Fig. 53 . Deutosternal groove with 7–8 transverse denticulate rows, usually with three paired smooth lateral transverse lines ( Fig. 54 ). The posterior fourth pair of lateral transverse lines arch-shaped, with large denticles, located at the level of pc setae. Setae h1–h3 smooth: h1 (35–37) longest, seta h2 (13–15) shorter than h3 (25–30); pc (18–20) serrated. Dorsal side of gnathosoma with the pair of protruding wedge-shaped structures between palpal coxa and trochanter, lateral to epistome ( Fig. 55 ). Palpal trochanter with seta al1 long and pilose in the distal third; with seta al2 short and smooth; palp genu with setae al1 and al2 pilose in distal third, palp apotele two-tined.

Legs. Lengths: I 325–340, II 275–285, III 27 5 –285, IV 325–340 µm. Chaetotaxy of legs I–IV: coxae 2, 2, 2, 1; trochanters 6 (1 1/3 1), 5 (1 1/3 0), 5 (1 1/3 0), 5 (1 1/3 0), femora 13 (2 5/4 2), 11 (2 5/3 1), 6 (1 4/1 0), 6 (1 4/1 0); genua 13 (2 6/3 2), 12 (2 6/2 2), 10 (2 4/2 2), 10 (2 5/2 1); tibiae 14 (2 6/4 2), 10 (2 4/2 2), 9 (2 3/2 2), 10 (2 4/2 2); tarsi 49, 18 (3 7/5 3), 18 (3 7/5 3), 18 (3 7/5 3). All legs with pair of sclerotised claws and pulvillus with five lobes. Pretarsus of legs II–IV with ambulacral stalk, legs I with sessile claws. Coxae I–IV grouped closely together vertically; coxae I split on dorsal side, coxae III–IV with recesses on anterolateral side. Coxae II–III with anterodorsal spines: coxae II with large sharp spine, coxae III with small one.

Male. ( Figs 56–59 , 74 and 81 , n=10).

Dorsal idiosoma. Dorsal shield suboval shape, 470–480 long and 315–335 wide. Ornamentation and chaetotaxy similar to that of female.

Ventral idiosoma. Tritosternum as in female. Pair weakly sclerotised presternal (jugular) platelets with pair of St1 setae ( Figs 56 , 74 , 81 ). First sternal platelet entire, with pair of St2 setae, with festoon and folds ornamentation, 28–30 long and 45–50 wide. Second sternal platelet entire, subcordate shape, ornamented by festoon lines and folds; with two pairs of setae St3, St4 and one pair of lyrifissures iv 3 in antero-lateral margins; 25–35 long on median line and 30– 45 wide at level of St3 setae; surrounds the genital opening. Genital opening located at level of coxae III; with a pair of eugenital setae, covering by two platelets ( Fig. 57 ), with pair of genital sclerites as in Fig. 58 . Third sternal platelet entire, triangular, 25–35 long and 25–45 wide, with St5 setae and pair of iv5 lyrifissures; in some specimens one opening of iv5 asymmetrically inserted in soft cuticle. Endo-, exopodal and metapodal shields absent. Peritrematal shields similar to that female, with five pairs of pore-like structures: gp1, gp2, i1 —ip3. Peritremes short, similar to those of female. Arch of vertex with two dorsal setae: pilose j1 and smooth thorn-shaped z1. Ventri-anal shield broad, 145–150 long and 235–250 wide, entire or with deep lateral incisions as in female; with festoon reticulation; with 7– 10 pairs of opisthogastric smooth setae and lateral rows of opisthonotal pilose setae, inserted posteriorly of incisions, each with 8–9 setae. The most posterior marginal row with elongated smooth setae on raised tubercles. Adgenital gland pores gv2 are multiple, dispersed over the surface: one pair of glands located in soft cuticle posteriorly of coxae IV, other 4–6 openings located in ventri-anal shield. Anal area as in female. Pair of glands gv3 located antero-laterad of para-anal setae. Opisthonotal shield curved on ventral side with pair of Po 4 glands.

Gnathosoma . Fixed digit of chelicera 48–50 long, with five teeth in addition to apical hook and leaf-shaped pilus dentilis ( Fig. 59 ). Movable digit of chelicera the same length as fixed digit, tridentate in addition to apical hook, with arthrodial corona at base of digit. Chelicera with long dorsal seta, lateral (antiaxial) and dorsal (paraxial) lyrifissures. Male chelicera lacking spermatodactyl, without sexual dimorphism. Epistome, corniculi, internal malae, hypostomal and palpal structures as in female.

Legs. Lengths: I 325–340, II 270–285, III 270–285, IV 315–340 µm. Chaetotaxy and morphology of legs as in female. Leg II without sexual dimorphism.

Deutonymph ( Fig. 60 , n=10). Dorsal idiosoma. Dorsal shield suboval shape, 415–450 long and 280–315 wide. Anterior margin of the podonotum curved ventrally to form a vertex, with pair of setae j1, z1 and lyrifissures ip1 ( Fig. 60 ). Podonotal and opisthonotal shields neotrichous, pore-like structures as in adults.

Ventral idiosoma. Presternal (jugular), first and second sternal platelets slightly distinct with pairs of St1–St3 setae accordingly; other setae St4, St5 inserted in soft cuticle. Peritrematal shields narrow, fused with dorsal shield laterally, with festoon reticulation along entire length; separated from peritremes. Five pairs of pore-like structures present, three of them inserted in soft cuticle: gp1, gp2 and ip2; ip 3 in small platelet posterior to stigmata. Peritremes straight or slightly curved, longer than in adults (150–157), reaching anterior level of coxae II; with internal cell structure. One pair of adgenital gland pores gv2 located in soft cuticle posteriorly to coxae IV. Opisthogastric area with 7–8 simple and pilose setae inserted in soft cuticle from each side asymmetrically. Anal shield elongated, 75–90 long and 50–55 wide, with pair of Jv3, para-anal and post-anal setae; with cribrum and pair of gv3 glands located antero-laterad to para-anal setae. Opisthonotal shield curved on the ventral side posteriorly, does not connect with anal shield, with 9–11 pilose setae inserted asymmetrically and the most posterior row with 14–16 smooth, curved setae from each side.

Gnathosoma . As in adults.

Legs. Lengths: I 280–305, II 245–250, III 245–250, IV 270–280. Chaetotaxy of legs as in adults.

Protonymph ( Figs 61–62 , n=10). Dorsal idiosoma ( Fig. 61 ). Dorsal idiosoma 315–335 long and 215–225 wide, with weakly sclerotised podonotal and pygidial shields. Anterior margin of podonotum curved ventrally to form a vertex, with setae j1 and z1. Podonotum with about 37–38 setae on each side (including marginal) and four pairs of pores; row j with six pairs of setae j1–j6; z row with recognisable z5 setae, homologies of other dorsal setae are obscure. Pygidial shield with about 30–32 setae on each side from dorsal view and three pairs of pores; pair of Po4 inserted in curved margins of pygidial shield on ventral side. Row J with three pairs of setae: J1, J3–J4 and some additional asymmetrical. Other pygidial setae multiple.

Ventral idiosoma ( Fig. 62 ). Presternal and sternal platelets not distinct. Setae St1–St3 and St5 inserted in soft cuticle; St5 minute seta, 3–4 long. Peritrematal shields very narrow, pore-like structures of periteremaral regions not distinct. Peritremes short (23–25), with internal cell structure; with thin ducts leading from stigmata. Opisthogastric area with 5–6 simple and pilose setae inserted in soft cuticle from each side. Anal shield with cribrum, as long as wide (45–50), with pilose para-anal and smooth post-anal setae; pair of glands gv3 located laterad to para-anal setae. Dorsal shield is curved on the ventral side, does not connect with anal shield; with 4–5 pairs of pilose setae, pairs of pores Po4, and posterior row of pilose curved marginal setae.

Gnathosoma . As in adults.

Legs. Lengths: I 220–250, II 195–210, III 195–210, IV 220–250. Chaetotaxy of legs I–IV: coxae 2, 2, 2, 1; trochanters 4, 4,4, 4; femora 10, 8, 5, 4; genua 8, 6, 6, 5; tibiae 8, 6, 7, 7; tarsi II–IV: 17, 17, 17. Structures of pretarsus and coxae I–IV as in adults and deutonymph, coxae III without distinct spine.

Larva ( Figs 63–65 , n=2). Dorsal idiosoma 225–230 long and 165–170 wide with podonotal, pygidial shields and three pairs of mesonotal sclerites ( Fig. 63 ). Podonotal shield with nine pairs of setae, including five pairs of j row setae; setae j1 the longest (18–20) located on anterior margin of shield; stout and pilose. Pygidium with eight pairs of setae: four short, brush-form and four marginal on large bases—long, curved, pilose. J -row with two pairs of setae.

Ventral idiosoma ( Fig. 65 ). Tritosternum as in adults. Sternal setae St1–St3 and St5 inserted in soft cuticle. Periremes and stigmas are absent. Pore-like structures not visible. Opisthogastric area with three pairs of setae inserted in soft cuticle, of which seta Jv2 the longest and smooth; three most posterior pairs of setae pilose, inserted on tubercles. Anal shield 20 long and 40 wide with pair of pilose para-anal and simple post-anal setae.

Gnathosoma . Gnathosoma in forward position not curved in ventral side of idiosoma ( Figs 64–65 ) with two simple hypostomal setae.

Legs. Structures of pretarsus and coxae of leg I–III as in protonymph.

Material examined. Holotype female, Russia, Altaiskii krai, North-Western Altai Mountains, Tigeretskii Range, Tigerekskii Nature Reserve, 1100 m a.s.l., 51 ̊04ʹ N, 83 ̊02ʹ E, Picea obovata-Abies sibirica-Pinus sibirica forest, in litter, 24 June 2017, leg. I.I. Marchenko. Paratypes: 7 females, same data as holotype; 7 females, 8 males, 700 m a.s.l., same geographical and locality data, in litter, 20 June 2017, leg. I.I. Marchenko; 1 male, same geographical and locality data, in litter, 7 August 2013, leg. I.I. Marchenko; 1 male, same geographical data, 1500 m a.s.l., Betula tortuosa forest, in litter, 7 August 2013, leg. I.I. Marchenko; 1 female, 3 males, 1 protonymph, same geographical data, 500 m a.s.l., Betula sp.- Abies sibirica forest, in litter, 5 August 2013, leg. I.I. Marchenko; 13 females, 3 males, same geographical data, 900 m a.s.l., in litter, 7 August 2013, leg. I.I. Marchenko; 3 females, 4 males, same geographical data, 1800 m a.s.l., subalpine woodlands with Pinus sibirica-Picea obovata-Juniperus sabina , 5 June 2017, leg. T.M. Krugova. Other material: 32 females, 2 males, 9 deutonymphs, 5 protonymphs, 1 larva, same geographical data as paratypes, 700, 1100 and 1800 m a.s.l., Picea obovata-Abies sibirica-Pinus sibirica forest, in litter, 7 August 2013, 20 and 24 June 2017, leg. I.I. Marchenko; 4 females, 2 males, same geographical data as paratypes, 600 m a.s.l., Caragana sp.- Spirea sp. bush, in litter, 22 June 2017, leg. I.I. Marchenko; 11 females, 1 deutonymph, 1 protonymph, same geographical data, 500 m a.s.l., Populus tremula- Abies sibirica forest, in litter, 7 August 2013, leg. I.I. Marchenko; 1 female, 1 male, 2 deutonymphs, same geographical data, environs of Tigerek village, Kozyr Mt., 500 m a.s.l., Betula sp.- Populus tremula forest, in litter, 24 June 2017, leg. I.I. Marchenko; 10 females, 7 males, 3 deutonymphs, 1 protonymph, Altaiskii krai, North- Western Altai Mountains, Baschelakskii Range, 51 ̊06ʹ N, 84 ̊24ʹ E, 1250 m a.s.l., Larix sibirica forest, in litter, 25 June 2012, leg. R. Yu. Dudko; 2 females, Central Altai Mountains, Ust’-Koksa Distr., environs of lower Multinskoe lake, Katunskii Range, 50 ̊00ʹ N, 85 ̊49ʹ E, 1500 m a.s.l., Abies sibirica-Pinus sibirica forest, in litter, 12 July 2013, leg. I.I. Marchenko.

Etymology. The species is named after russian folk dance “kazachok”, as the Cossacks lived in the Tigirek fort of Altai Mountains since the 18th century.

Remarks. Adults of Halozercon kazachok most similar to H. karacholana Wiśniewski et al. 1992 , but has a number of differences. Vertex of H. kazachok with pairs of j1, z1 setae and pore-like structures ip1 grouped closely together in anterior margin of shield; H. karacholana with z1 setae inserted far behind j1 setae. Dorsal setae of H. kazachok long and curved: podonotal setae 22–25 µm, opisthonotal setae 30–35 µm; H. karacholana with podonotal setae shorter and straight: 10–20 µm and opisthonotal 22–25 µm. Ventri-anal shield of H. kazachok with incisions extending to posterior edge of anal opening; female of H. kazachok with opisthogastral setae Jv1 inserted in soft cuticle. Ventri-anal shield of H. karacholana with incisions extending to anterior edge of anal opening; female opisthogastral setae Jv1 inserted in ventri-anal shield. Adult chelicera of H. kazachok sp.n. without sexual dimorphism, whereas fixed digit of male chelicera of H. karacholana with two basal and 5–6 small distal teeth and female fixed digit with five teeth.

Figures

FIGURE 48. Halozercon kazachok sp. n., female. Dorsal idiosoma.

FIGURES 49–50. Halozercon kazachok sp. n., female. 49. Ventral idiosoma; 50.Different variants of genital shields.

FIGURES 51–55. Halozercon kazachok sp. n., female. 51. Chelicera; 52. Epistome; 53. Gnathosoma with corniculi and internal malae; 54. Hypostome; 55. Gnathosoma, dorsal view.

FIGURES 66–69. Halozercon kazachok sp. n., SEM photos, female. 66. Dorsal idiosoma; 67–69. Ventral idiosoma.

FIGURES 70–74. Halozercon kazachok sp. n., SEM photos. 70–73. Female.70. Sternal and genital regions; 71. Peritrematal shield with peritrema; 72. Peritrema; 73. Gnathosoma; 74. Male, ventral idiosoma.

FIGURES 75–81. Halozercon kazachok sp. n., photos. 75–80. Female. 75. Dorsal idiosoma; 76. Opisthonotal shield; 77. Ventral idiosoma; 78. Incision of ventri-anal shield; 79. Sternal and genital regions; 80. Sternal shields; 81. Male, ventral idiosoma.

FIGURES 56–59. Halozercon kazachok sp. n., male. 56. Ventral idiosoma; 57. First and second sternal shields with genital opening; 58. Genital sclerites; 59. Chelicera.

FIGURES 60–62. Halozercon kazachok sp. n., 60. Deutonymph, ventral idiosoma. 61. Protonymph, dorsal idiosoma; 62. Protonymph, ventral idiosoma.

FIGURES 63–65. Halozercon kazachok sp. n., larva. 63. Dorsal idiosoma; 64. Dorsal view of gnathosoma; 65. Ventral idiosoma.