Aturus primoryensis, Semenchenko, Ksenia A. & Tuzovskij, Petr V., 2011

Semenchenko, Ksenia A. & Tuzovskij, Petr V., 2011, New water mites species of the genus Aturus Kramer (Acariformes, Aturidae) from the Far East of Russia, Zootaxa 2933, pp. 1-26 : 9-12

Aturus primoryensis sp. n.

( Figs. 20–26 )

Type series. Holotype: male (250-kas– IBSS), Russia, Primory Territory, Anuchinsky District, Arsenyevka River basin, small spring near Veseloe, N 43°40.133’; E 133°00.428’; depth 10–15 cm; substrate: cobbles, detritus. 14.09.2008, leg. K.A. Semenchenko, D.A. Sidorov. Paratypes: 2 males (248-249-kas– IBSS), 1 female (251-kas– IBSS), same data as holotype.

Description. Male. Idiosoma square. Frontal margin convex, with small median incision ( Fig. 20 ). Eyes located dorsally. Setae Fp, Oi and Pi without glandularia, other idiosomal setae associated with glandularia. Setae Fch and Oe longer and thicker than proterosomal setae Fp, Vi, Ve and Oi. Setae Vi and first pair of lyriform organs (i1) situated on small platelets. Dorsal surface with net structure, ventral surface porous. Dorsal shield separated from ventral shield, depression located anteriorly to pairs of setae Hi and extended to pairs of setae Si, another depressions between setae Hi and Se on each side; 1 piece of muscle attachment scar laterally to setae Oi and 2 pieces near setae Se on each side of idiosoma, with 6 pairs of setae: Oi, Hi, Si, Se, Ci and Pi; setae Hi long, thick, other setae short and thin. Setae Oe, He, Sci and Li situated on soft interscutal membrane. Setae Oe and He long and approximately subequal in length. All dorsal setae simple not bifurcate. Second pair of lyriform organs (i2) situated posterior to sclerites bearing setae Oe, i3 on sclerites bearing setae Sci, i4 posterior to Sce, i5 on dorsal shield laterally to setae Pi. Excretory pore opens on dorsal shield caudally between setae Ci. Posterolateral surface of dorsum with numerous short, thin setae, forming 1 transverse row and numerous long thick and thin setae located distally to distinct row of setae. Between assemblage of dorsal setae and setae Sce 2 genital acetabula.

Ventral shield ( Fig. 21 ) with deep median cleft and 11–17 genital acetabula on each side. Setae Pe and Le situated near posterolateral margins of venter. Median cleft with 4–7 thin setae on each side.

Capitulum slightly elongated with short anchoral process. Trochanter of pedipalp ( Fig. 22 ) short, thin with 1 dorsodistal seta. Ventral margin of femur nearly straight. Femur with 3 dorsoproximal setae and 3 dorsodistal ones. Genu with 2 dorsodistal setae, its ventral margin slightly concave. Tibia expanded distally with 2 ventrodistal setae (one thick and one thin), 2 thin dorsodistal ones and short distolateral spine.

Leg III unmodifed. Trochanter of leg IV ( Fig. 23 ) with single short proximal seta and 2 dorsodistal ones; basifemur IV curved; genu IV expanded distally, with 1 ventrodistal curved seta, 1 blade-like seta exceeding length of tibia and adjacent short sword-like seta, with 14–19 feathered and 4–5 smooth long and some dorsal short setae; tibia IV ( Fig. 5 ) with 10 feathered proximal and 4 smooth ventromedial setae, 1 feathered, 1 thick curved and 5 smooth distal setae, and 3 dorsal short setae; tarsus shorter than tibia, narrowed proximally and expanded distally with slightly convex dorsal margin. Claws ( Fig. 24 ) asymmetrical: one claw with a very long central denticle and short external and internal denticles (all three denticles with acute tips), other claw with short rounded external, longer wide rounded central and longest acute internal denticles.

Measurements (n=3). Length of idiosoma 416–436, width 369–376; length of dorsal shield 383–390, width 290–304; length of capitulum 100–108, width 90–94; length of basal segment of chelicera 78–84, length of cheliceral stylet 32–35; length of capitular bay 105–108; length of pedipalpal segments (P-1–5): 22–24, 62–65, 43–46, 86–89, 33–37; length of leg segments: I-L- 1–6—43 –54, 65–67, 56–59, 62–86, 92–100, 103–105; II-L- 1–6—51 – 56, 65–73, 62–66, 92–95, 100–108, 104–108; III-L- 1–6—55 –57, 78–84, 76–78, 121–127, 127–135, 124–127; IV- L- 1–6—81 –105, 184–186, 151–154, 181–189, 108–113, 103–108.

Female. Idiosoma flat. Dorsal and ventral shields present. Frontal margin straight, with small median incision ( Fig. 25 ). Setae Fp, Oi and Pi without glandularia; other idiosomal setae associated with glandularia. Setae Fch and Oe longer and thicker than proterosomal setae Fp, Vi, Ve and Oi. Setae Vi and first pair of lyriform organs (i1) situated on small platelets. Dorsal shield porous, bearing 4 pairs of setae: Oi, Hi, Si, Se, with small indentation in caudal part. Setae Oe, He, Sci, Li and Ci situated on smooth interscutal membrane, setae He longer than other ones. Second pair of lyriform organs (i2) situated posterior to sclerites bearing setae Oe, i3 posterior to sclerites bearing setae Sci, i4 posterior to Li, i5 on ventral surface laterally to setae Pi.

Excretory pore opens posterior to dorsal shield on sclerite between setae Ci. Coxal shield ( Fig. 26 ) occupying about 4/5 of ventral surface. Setae Sce and Pe situated between posterior margin of coxal shield and genital plates. Anterior genital sclerite slightly developed. Genital field with 20–22 pairs of acetabula, situated on plates along posterior margin of each side and forming 2 rows on major portion of genital plates, each genital plate bearing 2 median thin setae. Pedipalps similar to those of male.

Measurements (n=1). Length of idiosoma 475, width 442; length of dorsal shield 409, width 350; length of capitulum 113, width 90; length of basal segment of chelicera 70, length of cheliceral stylet?; length of capitular bay 100; length of pedipalpal segments (P-1–5): 21, 70, 40, 86, 35; length of leg segments: I-L- 1–6—51, 65, 59, 81, 86, 95; II-L- 1–6—49, 59, 54, 73, 81, 92; III-L- 1–6—48, 67, 65, 100, 110, 110; IV-L- 1–6—59, 89, 94, 124, 119, 113.

Differential diagnosis. Aturus primoryensis sp. n. is closely related to A. quadratus Kim & Chung, 1995 described from South Korea. The new species differs from the latter in the following characters (character states of A. quadratus are given in parentheses, data taken from Kim & Chung 1995): the dorsal shield not concave on posterolateral sides (concave); setae Hi located anterior to the middle of the dorsal shield (directly on the middle of dorsal shield); 11–17 genital acetabula on each side of idiosoma on the ventral shield, 2 of them situated on dorsal side (6–7 genital acetabula in total, all on ventral side); genu of leg IV with 14–19 feathered and 4–5 smooth long ventral setae (5 feathered and 3 smooth long ventral setae); tibia of leg IV with 10 feathered proximal and 4 smooth ventromedial setae, 1 feathered, 1 thick curved and 5 smooth distal setae (7 feathered proximal and 4 smooth ventromedial setae, 1 feathered, and 5 smooth distal setae, thick curved seta absent); claws both with 3 denticles (one claw represented on Fig. 6 E has 2 denticles).

Etymology. The species epithet primoryensis is named after the region where it was collected (Primory Territory).

Habitat. Running waters.

Distribution. Russia: Far East, Primory Territory.

Figures

FIGURES 20 – 24. Aturus primoryensis sp. n., male: 20, idiosoma, dorsal view; 21, idiosoma, ventral view; 22, pedipalp, lateral view; 23, leg IV; 24, claws of leg IV. Scale bars = 100 µm for Figs. 20 – 21; 50 µm for Fig 23; 25 µm for Figs. 22, 24.

FIGURES 25 – 26. Aturus primoryensis sp. n., female: 25, idiosoma, dorsal view; 26, idiosoma, ventral view. Scale bar = 100 µm.

FIGURES 1 – 5. Aturus triangularis sp. n., male: 1, idiosoma, dorsal view; 2, idiosoma, ventral view; 3, pedipalp, lateral view; 4, leg IV; 5, claws of leg IV. Scale bars = 50 µm for Figs. 1 – 2, 4; 25 µm for Figs. 3, 5.

FIGURES 6 – 7. Aturus similis sp. n., male: 6, idiosoma, dorsal view; 7, idiosoma, ventral view. Scale bar = 100 µm.