Feltria (Feltria) cornuta rossica, Tuzovskij, Petr V. & Semenchenko, Ksenia A., 2009

Tuzovskij, Petr V. & Semenchenko, Ksenia A., 2009, New water mites species of the genus Feltria Koenike (Acariformes, Feltriidae) from the Asian Russia, Zootaxa 2124, pp. 38-50 : 45-49

Feltria (Feltria) cornuta rossica ssp. n.

( Figs. 17–26 )

Type series. Holotype: female (9498– IBIW), Russia, Khabarovsk Territory, Chegdomynsky District, the Bureya River basin, the Mylny spring, N 51°01.480’; E 132°24.481’; depth 20 cm; substrates: boulders, stones, pebbles, moss. 22.09.2005, coll. D.A. Sidorov. Paratypes: 1 female (30-kas– IBSS), 1 male (9498– IBIW) with same locality and date as holotype; 1 male (31-kas– IBSS) Russia, Sakha Republic (Yakutia), Neryngrynsky District, the Lena River basin, headwater of the Bolshoy Duray River, N 57°12.237’; E 124°48.314’; depth 40 cm; substrates: stones, small-grained sand. 0 2.08.2006, coll. K.A. Semenchenko, D.A. Sidorov; 1 male (9499– IBIW), Russia, Sakha Republic (Yakutia), Nyzhnekolymsky ulus, Letyatkin Cape, the Kolyma River basin, unnamed spring. 22.08.2008, coll. H. Abé.

Description. Female. Dorsum with central shield and four pairs of platelets ( Fig. 17 ). Dorsal shield relatively small (ratio length/width = 1.07–1.16), cross-shaped, with well developed lateral protrusion and bearing two pairs of setae: Oi and Sci. Setae Fch, Fp, Vi, Ve, Hi, He, Sce, Li, Le, Ci and Pi located free on smooth integument; setae Oe placed on first pair of lateral plates, setae Si on fourth pair of lateral plates. Setae Fp, Oi and Pi without glandularia, other idiosomal setae associated with glandularia. Setae Fch, Oi and Sci thick, other idiosomal setae thin. First and second pairs of lateral plates nearly equal in size, forth pair of lateral plates much larger than third pair of lateral ones. First pair of lyriform organs (i1) placed on platelets, bearing setae and glandularia Vi, other lyriform organs (i2–i5) lying free on smooth integument along lateral portions of body. Excretory pore plate slightly broader than long, located dorsally. Setae Pi and Ci separated.

All coxal groups separated ( Fig. 18 ). Posterior apodemes of first coxae short and directed laterally. Second coxae not extending to midline. Posterior extensions of fourth coxae slightly developed. Acetabular plates separated, with 26–33 genital acetabula and three thin median setae (two proximal and one distal) on each side. Acetabular plates with distinctly developed posteromedial corners. Pregenital sclerite small, located between posteromedial corners of posterior extensions of fourth coxae and platelets, bearing setae Pe. Anterior genital sclerite slightly broader than long. Setae Pe and Se with associated glandularia lying free on smooth integument between posterior extensions of fourth coxae and genital area. Ventrolateral plates narrow, transverse and lying free between fourth coxae and acetabular plates.

Pedipalp ( Fig. 19 ) rather slender. Trochanter relatively short, with single dorsodistal seta. Femur slightly expanded, with three proximal and three thick dorsodistal setae, its ventral margin is straight. Genu with one proximal and two dorsodistal setae. Tibia ventrally with small ventrolateral projection near middle, bearing proximal seta, distal seta without tubercle located more distal.

Measurements (n=2). Length of body 450–475, width 395–435; length of dorsal shield 265–303, width 228–283; length of seta Fch 54; length of genital plates 115–119, width 132–163; length of capitulum 90; length of pedipalpal segments (P 1–5): 25–27, 36–44, 36–41, 60–71, 37–39; length of coxae I–IV 180–264; length of leg segments: I — 27–36, 37–54, 42–44, 60–65, 72–82, 78–92; II — 34 –36, 38–51, 47–48, 60–64, 78–85, 81–95; III — 40 –42, 41–48, 54–66, 69–75, 90–98, 90–102; IV — 69 –75, 51–54, 60–64, 90–98, 108–122, 93–114.

Male. Body flat and almost rounded (ratio length/width without coxae 1.02). Dorsum with large shield ( Fig. 25 ). Anterior margin convex. Dorsal shield with five pairs of setae: Oi, Oe, Sci, Li and Si; setae Oi without glandularia, other setae associated with glandularia; setae Oe thicker than other setae on this shield.

Dorsal shield slightly elongated, ratio length/width = 1.2–1.3. Setae Fch long and thicker than other dorsal setae. Setae Vi and first pair of lyriform organs located on common platelets; other setae and lyriform organs (i2–i5) lying free on smooth integument. Setae Hi thicker than He.

All coxal groups separated ( Fig. 26 ). Posterior apodemes of first coxae moderately long and directed more or less laterally. Second coxae not extending to midline. Anterior margin of acetabular plate convex; 27–32 acetabula on each side. Gonoporus small, narrow, located near anterior margin of acetabular plates, with 2–6 perigenital setae. Pregenital sclerite small, located between posteromedial corners of posterior extensions of fourth coxae and anterior margin of acetabular plate. Setae Pe and Se lying free between posterior extensions of fourth coxae and anterior margin of acetabular plate. Ventrolateral plates narrow, transverse and lying free between fourth coxae and acetabular plate. Excretory pore platelets, setae Pi and Ci not fused with acetabular plate ( Fig. 20 ).

Pedipalp relatively short ( Fig. 21 ). Trochanter with single dorsodistal seta. Femur expanded with three proximal and three dorsodistal setae, its ventral margin straight. Genu with one proximal and two dorsodistal setae. Tibia ventrally with well developed, curved, sharply-pointed projection near middle, much smaller setal tubercle located more distal, and with one thin dorsodistal seta.

Tibia of leg III ( Fig. 22 ) with four unequal thick distal setae and several thin setae; tarsus with moderately developed ventrolateral protrusion, bearing three short blunt setae ( Fig. 23 ). Leg claws ( Fig. 24 ) with three dents: large median, short and thin internal and external ones. Ventral margin of claw plate straight or slightly concave.

Measurements (n=2). Length of body without coxae 310–330, width 285–310; length of dorsal shield 280–290, width 215–235; length of seta Fch 50; length of genital plate 108–125, width 204–228; length of capitulum 90–95; length of pedipalpal segments (P 1–5): 21–24, 47–49, 36–39, 60–63, 36–39; length of coxae I–IV 240–245; length of leg segments: I — 30–35, 42–48, 39–42, 54–60, 65–72, 72–78; II — 30–38, 39–42, 36–39, 54–57, 65–72, 78–81; III — 42 –45, 36–39, 45–48, 60–63, 83–85, 78–84; IV — 70 –73, 48–51, 54–60, 78–81,100–105, 95–96.

Differential diagnosis. The present subspecies is closely related to F. cornuta cornuta Walter, 1927 but differs from it in the following characters (character states of F. cornuta cornuta are indicated in parentheses from Bader 1976): in female, the dorsal shield cross-shaped with well developed lateral protrusion (oval without lateral protrusion or its slightly developed); length and width of the dorsal shield almost subequal in female, ratio L/W =1.07–1.16 (elongated, ratio L/W = 1.42–1.52; 1.28 according to Lundblad (1956); the anterior genital sclerite transverse (longitudinal).

It should be noted that in female of F. c o r n u t a cornuta in Lundblad’s description ( Lundblad 1956) the platelets, bearing setae Oe, are fused with the dorsal shield, however this specimen is probably aberrant.

Etymology. The subspecies is named after the country where it was collected ( Russia).

Habitat. Running waters.

Distribution. Khabarovsk Territory (Far East of Russia) and Sakha Republic (Siberia).

Figures

FIGURES 17 – 18. Feltria cornuta rossica ssp. n., female: 17, idiosoma, dorsal view; 18, idiosoma, ventral view. Scale bar = 100 μm.

FIGURES 19 – 24. Feltria cornuta rossica ssp. n., female (19) and male (20 – 24): 19, pedipalp, lateral view; 20, acetabular plate; 21, pedipalp, medial view; 22, tibia and tarsus of leg III; 23, tarsus of leg III; 24, claw of leg IV. Scale bars = 50 μm for Figs. 19 – 23; 25 μm for Fig. 24.

FIGURES 25 – 26. Feltria cornuta rossica ssp. n., male: 25, idiosoma, dorsal view; 26, idiosoma, ventral view. Scale bar = 100 μm.