Gamasiphis ochotensis, Marchenko, Irina I., 2013

Marchenko, Irina I., 2013, A new species of Gamasiphis Berlese (Acari: Ologamasidae) from Russia (Sakhalin and Kuril Islands) with a key to the Asian species, Zootaxa 3741 (1), pp. 172-180 : 173-177

Gamasiphis ochotensis sp. n.

Diagnosis of adults (female and male). Anteromedial extension of epistome aciculate; all idiosomal setae aciculate; podonotal region of dorsal shield with 23 pairs of setae; opisthonotal region with 12 pairs of setae; seta j 4 about 0.9 times as long as distance between its base and base of j 5; seta z 6 about as long as j 6; setae s 3 and s 6 about 0.3 times as long as s 5; seta j 6 about 0.7 times as long as distance between its base and base of J 2; four pairs of J setae; two pairs of pre-sternal platelets; ventrianal shield with eight pairs of setae in addition to circum-anal setae (Jv 1- Jv 5, Zv 1- Zv 3); seta Zv 2 about 0.8 times as long as distance between its base and base of Zv 3; seta Jv 5 about 5 times as long as circum-anal setae; setae Jv 3 inserted at the level of unsclerotized line which partly separates the dorsal and ventrianal shields; seta Jv 5 inserted posterior to unsclerotized line which partly separates the dorsal and ventrianal shields; distance between ends of these unsclerotized lines equal to distance between bases of Jv 3; sclerotized diagonal section laterad of ventrianal shield is broad, with wide about 0.8 times as long as Zv 3 at the level of pore.

Female. ( Fig. 1–7 ) (five specimens measured).

Gnathosoma: Fixed cheliceral digit 50–52 µm long with seven teeth in addition to apical tooth and a setiform pilus dentilis ( Fig. 1 ). Movable cheliceral digit 48–50 µm long, with four teeth in addition to apical tooth. Dorsal cheliceral seta, lateral (antiaxial) and dorsal lyrifissures distinct. Epistome with anteromedian extension smooth and aciculate, with a pair of short anterolateral spines; some specimens with a pair of denticles between anteromedian extension and anterolateral spines ( Fig. 2 A–B). Deutosternal groove of hypostome with eight rows of denticles, each bearing 6–14 denticles, except most basal row smooth ( Fig. 3 ); anterior row V-shaped, followed by an inverted V-shaped row, subsequent rows roughly transverse; margins of groove not distinct. Setae h 1 and h 3 equal in length (25–30 µm), h 2 shorter (17–20 µm), Sc (h 4) (20–25 µm). Salivary styli well developed ( Fig. 2 B). Internal malae fimbriate laterally. Corniculi 30–32 µm long, 12–15 µm wide at the widest point ( Fig. 3 ). Palp chaetoxy 2-5-6-14 -15; palp trochanter with one small ventral protuberance ( Fig. 4 ); setae al 1 and al 2 of palp genu slightly stout; palp apotele 3-tined.

Dorsal idiosoma ( Fig. 5 ): Dorsal shield entire, ovoid shape, smooth, totally covering dorsal surface; 410–430 µm long, 300–325 µm wide at level of coxa IV. Dorsal shield with 35 pairs of acicular setae. Podonotal region with 23 pairs of setae (j 1- j 6, z 1- z 6, s 1- s 6, r 2- r 6), 12 pairs of distinguishable lyrifissures (two pairs visible ventrally on mounted specimens) and two pairs of pores (mediad of r 3 and posterior to and mediad of r 6; visible ventrally on mounted specimens); with numerous sigilla posterior to j 5. Opisthonotal region with 12 pairs of setae (J 2- J 5, Z 2- Z 5, S 2- S 3, R 2- R 3); Z 5 slightly serrated; with 10 pairs of distinguishable lyrifissures (one pair visible ventrally on mounted specimens) and one pair of pores (gdZ 2, anterior and mediad to Z2). Length of setae: j 1 (10–12), j 2 (25– 30), j 3 (40–45), j 4 (40–45), j 5 (45–50), j 6 (40–45), z 1 (7–10), z 2 (7–10), z 3 (35–40), z 4 (45–50), z 5 (40–45), z 6 (40–45), s 1 (7–10), s 2 (7–10), s 3 (10–12), s 4 (40–45), s 5 (40–45), s 6 (10–12), r 2 (7–10), r 3 (7–10), r 4 (7–10), r 5 (10–12), r 6 (7–10), J 2 (7–10), J 3 (7–10), J 4 (7–10), J 5 (7–10), Z 2 (7–10), Z 3 (7–10), Z 4 (7–10), Z 5 (60–62), S 2 (10–12), S 3 (10–12), R 2 (7–10), R 3 (10–12).

Ventral idiosoma ( Fig. 6 ): Base of tritosternum equal in length and wideth (12–17µm), laciniae (70–75 µm) totally separated from each other, pilose. Pre-sternal area with two pairs of presternal platelets. Sternal shield reticulate anteriorly between st 1 and st 2, smooth posteriorly; 57–62 µm long at mid-line and 135–140 µm wide between coxae II and III; with four pairs of setae (st 1, st 2, st 4 acicular; st 3 stout), st 3 inserted about in transverse line and mediad to st 2; distance between st 3– st 3 as long as st 3 seta (17–20 µm); and with four pairs of lyrifissures. Endopodal shields fused with and distinctly more sclerotised than sternal shield. Peritreme extending anteriorly to anterior margin of coxa I. Peritrematic shield fused with section of exopodal shield near to coxa IV, widest at level of posterior margin of coxa IV, with a lyrifissure posterior to stigma. Length of peritrematic-exopodal shield from stigma to posterior margin 70–75 µm, width 42–45 µm at level of posterior margin of coxa IV. Band of dorsal shield extending laterad to the fused peritrematic-exopodal shield ending sharply in posterior margin. Genital shield wider than long, 62–67 µm long and 100–102 µm wide, hyaline apex abutting the sternal shield; anterior margin rounded and posterior margin truncate, with a pair of setae st 5 and three pairs of sigilla; distance between st 5- st 5 60–63 µm. Ventrianal shield with transverse striations anterior to Jv 4 and smooth posteriorly; 180–190 µm long from anterior margin to post-anal seta and 200–210 µm wide at widest point; with eight pairs of acicular setae (Jv 1- Jv5, Zv 1- Zv 3) in addition to post-anal and para-anal setae; with five pairs of lyrifissures (antero-lateral margin of the shield, posterior to and laterad of Zv 1, posterior to and laterad of Zv 2, anterior to and mediad of Zv 3 and laterad of circum-anal seta); distance between Jv 5 and anterior margin of anal opening about 0.5–0.7 times as long as anal opening; seta Jv 5 about 5 times as long as circum-anal seta; post-anal seta about 4 times as long as para-anal setae, the latter situated at level of the posterior margin of anal opening. Dorsal and ventrianal shields partly separated by an unsclerotised line, the ends of this line reach the bases of Jv 3; seta Jv 3 situated at the level of this line; distance between Jv 3 and post-anal setae 70-80 µm. Sclerotised diagonal section laterad of ventrianal shield that connects the latter to the dorsal shield is broad, with one pair of pores; 18–20 µm wide at the level of pore; ending sharply at anterior part and ending broadly near of Zv 3 seta at posterior part. Length of ventral setae: st 1 (27–32), st 2 (25–30), st 3 (17–20), st 4 (25–27), st 5 (22–25), Jv 1 (20–25), Jv 2 (17–22), Jv 3 (20–25), Jv 4 (27–32), Jv 5 (50–55), Zv 1 (20–25), Zv 2 (20–25), Zv 3 (20–25), circum-anal (10–12) and post-anal seta (40–45).

Spermatheca: Opening of spermathecal apparatus tubular, extending medially from base of coxa IV ( Fig. 7 ). Other parts of spermatheca not clearly visible.

Legs: Lengths: I: 320–330, II: 275–288, III: 230–250, IV: 325–345 µm. Chaetotaxy of legs I–IV: coxa 2, 2, 2, 1; trochanter 6, 5, 5, 5; femur (2 3/2 2/2 2), (2 3/1 2/2 1), (1 2/1 2/0 0), (0 2/2 2/0 0); genu (2 3/2 3/1 2), (2 3/1 2/1 2), (2 2/1 2/0 1), (2 2/1 3/0 0); tibia (2 3/2 3/2 2), (2 2/1 2/1 2), (2 1/1 2/1 1), (2 1/1 3/1 1). All leg setae acicular, except one antero-lateral pilose seta on trochanter II. All legs with pretarsus, each with elongate ambulacral stalk and a pair of strongly sclerotised claws, with three rounded pulvilli; claws of pretarsus I slightly smaller than others.

Male. ( Fig. 8–12 ) (five specimens measured).

Gnathosoma: Fixed cheliceral digit 47–49 µm long, with six teeth in addition to apical tooth, with transverse line across the digit and a setiform pilus dentilis ( Fig. 8 A–C). Movable cheliceral digit 45–47 µm long, with one tooth in addition to apical tooth. Spermatodactyl curved; with an internal canal along proximal part (2/3 length of spermatodactyl) and with distal part spatulate (1/3 length of spermatodactyl). Total length of spermatodactyl 65–70 µm, free process 30–35 µm long. Dorsal cheliceral seta, lateral (antiaxial) and dorsal lyrifissures distinct. Corniculi 25–27 µm long, 7–10 µm wide ( Fig. 9 ). Epistome and hypostome as in female. Setae h 1 and h 3 equal length (25– 27 µm); setae h 1 and Sc equal length (20–25 µm) and slightly shorter than other. Palps as in female.

Dorsal idiosoma: 375–400 µm long, 275–300 µm wide. Dorsal shield similar to that of female. Measurements of setae: j 1 (10–12), j 2 (25–30), j 3 (40–45), j 4 (40–45), j 5 (40–50), j 6 (35–40), z 1 (7–10), z 2 (7–10), z 3 (35–40), z 4 (40–50), z 5 (40–50), z 6 (40–50), s 1 (7–10), s 2 (7–10), s 3 (10–12), s 4 (40–50), s 5 (40–50), s 6 (10–12), r 2 (7–10), r 3 (7–10), r 4 (7–10), r 5 (10–12), r 6 (7–10), J 2 (7–10), J 3 (7–10), J 4 (7–10), J 5 (7–10), Z 2 (7–10), Z 3 (7–10), Z 4 (7– 10), Z 5 (55–65), S 2 (10–12), S 3 (10–12), R 2 (7–10), R 3 (7–10).

Ventral idiosoma: Base of tritosternum 10–12 µm long and 15–18 µm wide proximally, lacinae (70–75 µm) totally separated from each other, pilose ( Fig. 10 ). Except for the fusion of sternal and genital shields (sternogenital shield), shape, pattern and fusions of ventral shields as in female. Sternogenital shield reticulate between st 1 and st 2, smooth posteriorly; 100–110 µm long and 130–140 µm wide at widest point between coxae II and III; with five acicular setae (s t 1– st 5), distance st 1– st 1 45–50 µm, st 2– st 2 70–75 µm, st 3– st 3 80–85 µm, st 4– st 4 80–85 µm and st 5– st 5 70–75 µm; with four pairs of lyrifissures. Ventrianal shield 210–220 µm long from anterior margin to postanal seta and 200–210 µm wide at widest point; with eight pairs of setae (Jv 1– Jv 5, Zv 1– Zv 3) in addition to postanal and circum-anal setae; and with five pairs of lyrifissures (antero-lateral margin of the shield, posterior to and laterad of Zv 1, posterior to and laterad of Zv 2, anterior to and mediad of Zv 3 and laterad of circum-anal seta); postanal seta about 4 times as long as circum-anal seta. Length of ventral setae: st 1 (25–30), st 2 (25–30), st 3 (20–25), st 4 (25–30), st 5 (20–25), Jv 1 (20–25), Jv 2 (20–25), Jv 3 (20–25), Jv 4 (30–35), Jv 5 (45-50), Zv 1 (20–25), Zv 2 (20– 25), Z 3 (20–25), circum-anal (10–12) and post-anal seta (40–45).

Legs: Lengths: I: 300–315, II: 260–275, III: 230–245, IV: 310–325 µm. Chaetotaxy of legs similar to that of female. Leg II with one antero-lateral pilose seta on trochanter (similar to female); femur with two ventral spur-like setae (one large spur 30–35 µm length and one small spur on elevated base); genu with two small ventral spur-like setae; tibia with one small ventral spur-like seta; tarsus with one acicular ventral seta on raised base ( Fig. 11–12 ). All other setae of legs acicular. All legs with pretarsus, elongate ambulacral stalk, a pair of strongly sclerotised claws, with three rounded pulvillus; claws of pretarsus I slightly smaller than others, similar to those of female.

Material examined. Holotype female, 33 paratype females and 11 paratype males from litter of forest with Betula ermanii —bamboo Sasa spp. and Abies sakhalinensis — Picea glehnii at Chekhov Mounting (47°00' N, 142°50' E), Susunaiskii Ridge, south of Sakhalin Island, Russia, 9 August 1990, collected by I. Volonikhina (Marchenko); 15 paratype females and 14 paratype males from litter at forest with Abies sakhalinensis ; Querqus mongolica — Betula ermanii and forest with Ulmus spp. at south of Kunashir Island (43°50' N, 145°30' E), Russia, 18 July and 20 July 1989, collected by I. Volonikhina (Marchenko); two paratype females and three paratype males from bog with moss and Ledum palustre , in moss at environs of Yuzhno-Kurilsk, Kunashir Island, Russia, 4 August 1989, collected by I. Volonikhina (Marchenko); three paratype female and two paratype males in litter with bushes of Alnus spp. and Taxus cuspidate at Shikotan Island (43°48' N, 146°51' E), 30 October 1986, collected by S. Kalabin.

Holotype and 51 paratypes (30 females and 21 males) deposited at Zoological Museum of the Institute of Systematics and Ecology of Animals, Novosibirsk, Russia; 32 paratypes (23 females and nine males) deposited at arthropod collection of Manchester Museum, Manchester, United Kingdom.

Other examined material: 11 females and two males from mosses – lichens – blueberries (Vaccinum spp.) and in litter in a forest of Abies sakhalinensis – Picea glehnii and Betula ermanii –bamboo Sasa spp. at Chekhov Mounting, Susunaiskii Ridge, south of Sakhalin Island, Russia; five females from litter of mixed forest at environs of Ogonki, South Sakhalin, Russia; eight females and six males from litter in a forest of Abies sakhalinensis , in litter of mixed forest with Betula ermanii and Alnus spp., in a broadleaved forest, in a fumarole field with Pinus pumila , in bog with moss and Ledum palustre , at Kunashir Island, Russia; two females from bushes of Juniperus sargentii and Alnus spp. at Shikotan Island, Russia.

Etymology. The name ochotensis refers to the name of Okhotsk Sea that bathes Sakhalin and Kuril Islands from the North.

Remarks. Gamasiphis ochotensis sp. n. is most similar to Gamasiphis angaridis Marchenko, 2013 , but females of the latter have setae s 3 and s 6 as long as s 5; distance between bases of st 3– st 3 about 0.5 times as long as st 3; seta Jv 3 inserted posteriorly of unsclerotized line which separates partly the dorsal and ventrianal shields; sclerotised diagonal section laterad of ventrianal shield is narrow, with width at the level of pore about 0.3 times shorter than length of Zv 3; and males have spermatodactyl widest at proximal part and gradually narrowing apically, and tarsus II with a spur-seta. It is also similar to Gamasiphis lanceolatus Karg, 1987 , but females of the latter have 22 pairs of podonotal setae (s 1 absent) and 13 pairs of opisthonotal setae (S 1 present); dorsal setae j 2– j 6, z 3– z 6, s 4– s 5 and z 5 distally expanded; and males have spermatodactyl with very narrow distal part, about 0.5 times as long as total length of spermatodactyl.

Figures

FIGURES 1 – 7. Gamasiphis ochotensis sp. n. Female. 1. Antiaxial view of chelicera; 2. Epistome: A – B variations of shape; B—epistome and salivary; 3. Hypostome; 4. Palp trochanter; 5. Dorsal view of idiosoma; 6. Ventral view of idiosoma; 7. Spermatheca.

FIGURES 8 – 12. Gamasiphis ochotensis sp. n. Male. 8. Chelicera: A – C variations of spermatodactyl shape, A, B—antiaxial view, C—paraxial view; 9. Corniculi; 10. Ventral view of idiosoma; 11. Leg II; 12. Spur-like setae of femur II.