Unionicola primoryensis, Tuzovskij, Petr V. & Semenchenko, Ksenia A., 2015

Tuzovskij, Petr V. & Semenchenko, Ksenia A., 2015, Water mites of the genus Unionicola Haldeman, 1842 (Acari, Hydrachnidia, Unionicolidae) in Russia, Zootaxa 3919 (3), pp. 401-456 : 445-448

Unionicola primoryensis sp.n.

( Figs 38A–B , 39A–F , 40A–C )

Type series. Holotype: male (slide 325-kas-IBSS), Russia, Primory Territory, Khankaysky District, Khanka Lake, Astrakhansky Bay, from mantle cavity of Lanceolaria chankensis Moskvicheva , 16.07.2004, leg. E.I. Barabanschikov. Paratypes: 2 males (slide 522-kas-IBSS), 2 females (slides 326, 523-kas-IBSS), same data as holotype. Additional material: 20 females not preparated and fixed in Koenike’s solution.

Diagnosis. Adults. Dorsal shield elongate covering almost the whole idiosoma in males and corresponding to length of coxal plates in females, with lateral furrows in both sexes; posterior margin of coxal plates IV directed posterolaterally; P-2 very large, with five short setae; P-3 with long proximal and short distal seta; P-5 short with three distal unequal spines; females genital plates with middle extensions, each bearing three large inner subequal setae, with 13–16 genital acetabula on each side; genital plates of male fused to each other, with 11–13 genital acetabula on each side; IV-L-4 and IV-L-5 with three short swimming setae; all leg claws bifid.

Description. Female. Dorsal shield ( Fig. 40A ) shorter than in males and corresponding to length of all coxal plates. Anterior and posterior coxal groups ( Fig. 40B ) divided by very narrow interspace or adjoin in middle parts. Apodemes of first coxal group well extending beyond to anterior margin of third coxae. Coxal plates III+IV elongated (L/W ratio 1.7) with straight medial margin, posterior margin of coxal plate IV directed posterolaterally. Genital acetabula 13–16 pairs, lying on two genital plates, relatively small and occupy less than half of area of each plate ( Fig. 40C ). Genital plate with middle extension, bearing two long, thick setae and one long, thick seta posterior to extension.

Pedipalps ( Fig. 39F ) short and stocky: P-2 with five short setae; P-3 with long proximal and short distal seta; P-4 slightly tapering distally, with twosmall tubercles distally to middle of segment and proximal one bearing thin short seta; P-5 short with three unequal distal spines and slightly concave ventral margin.

Measurements (n=2). Idiosoma L 1360–1394; coxae III+IV L 748–816, W 408–460; length of all coxae 1037–1095; dorsal platelets L 1050–1088, W 566–612; genital plates L 198–224, W 158–178; pedipalpal segments (P–1–5) L: 33–39, 211–231, 73–86, 156–158, 56–66; leg segments L: I-Leg-1–6—132–138, 158–172, 185–191, 231–250, 204–218, 165–170; II-Leg-1–6—125–133, 178–211, 204–284, 270–356, 260–316, 230–232; III-Leg- 1–6—132–133, 158–190, 224–277, 280–363, 271–330, 228–231; IV-Leg-1–6—211–264, 215–251, 270–275, 400–430, 575–581, 462–475.

Male. Dorsal shield ( Fig. 38A ) elongate covering almost the whole idiosoma, with lateral furrows anteriorly to middle of shield. Anterior and posterior coxal groups ( Fig. 38B ) fused to each other medially and divided by narrow interspace only in lateral parts. Sclerites, bearing setae and glandularia Le, not larger than sclerites bearing other idiosomal setae. Apodemes of first coxal groups well extending beyond to anterior margin of third coxae. Coxal plates III+IV fused to each other and posterior part of ventral shield. Surface of all coxal plates with reticulations. Genital plates fused to each other, with 11–13 small genital acetabula and five to six short, thin medial setae on each side ( Fig. 39A ). Palps as in females.

Figure 39B shows the proportion and chaetotaxy of the first leg, it shorter and thicker than legs II–IV. Legs II–IV relatively short, thick, all segments, except trochanter, cylindrical; three short swimming setae on IV-L-4 and IV-L-5 ( Fig. 39C ). Claws of legs I ( Fig. 39D ) with two subequal clawlets; claws of legs II–IV with long ventral clawlet and relatively short dorsal ( Fig. 39E ).

Measurements (holotype; in parentheses paratype, n = 1). Idiosoma L 1122 (1105); coxae III+IV L 880 (884); dorsal platelets L 1088 (1090), W 580 (630); genital plates L 163 (139), W 218 (198); pedipalpal segments (P–1–5) L: 60 (?), 198 (205), 80 (86), 152 (145), 60 (59); leg segments L: I-Leg-1–6—112 (?), 152 (125), 165 (152), 211 (185), 210 (172), 185 (132); II-Leg-1–6—118 (112), 146 (145), 218 (172), 250 (205), 252 (204), 180 (178); III- Leg-1–6—125 (118), 165 (152), 166 (205), 211 (244), 210 (237), 185 (198); IV-Leg-1–6—185 (211), 198 (204), 215 (210), 336 (330), 436 (475), 304 (389).

Deutonymph. Unknown.

Larva. Unknown.

Differential diagnosis. The new species is similar to Unionicola thienemanni Viets, 1957 , known from China, Borneo and Thailand ( Viets 1957; Vidrine 1986; Wen & Zhu 1996), but differs in the following characters (character states of U. thienemanni are given in parentheses, data taken from Viets 1957): genital plates with 11–13 pairs of genital acetabula in males, 13–16 in females (19–24 in males, 27 in females); dorsal shield length in females corresponds to length of coxal plates (shorter than coxal plates); claws of legs I thin, sickle-shaped (thick, hook-like). Most probably the specimens described as U. thienemanni from China ( Wen & Zhu 1996) refers to U. primoryensis sp.n. Females from China have small number of genital acetabula (11–12 pairs) and dorsal shield corresponding to length of coxal plates, the other significant characters of these specimens are unclear.

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

Habitat. Lakes.

Hosts. Lanceolaria chankensis Moskvicheva (Unionidae) .

Distribution. Russia (PrimoryTerritory).

Figures

FIGURES 38 A – B. Unionicola primoryensis sp. n., male (holotype): A, dorsal view, B, ventral view. Scale bars = 100 Μm.

FIGURES 39 A – F. Unionicola primoryensis sp. n., adults: A, genital field; B, I-Leg- 1 – 6; C, IV-Leg- 1 – 6, rotated; D, claw of leg I; E, claw of leg IV; F, pedipalp; A – E, male (holotype); F, female. Scale bars: A – C, F = 100 Μm, D – E = 25 Μm.

FIGURES 40 A – C. Unionicola primoryensis sp. n., female: A, dorsal view, B, ventral view, C, genital field. Scale bars = 100 Μm.