Torrenticola (Torrenticola) ungeri (Szalay, 1927)

Tuzovskij, Petr V., K. O, . & ., 2015, First record of the water mite Torrenticola ungeri (Szalay, 1927) (Acari, Hydrachnidia, Torrenticolidae) from Russia, Ecologica Montenegrina 2 (3), pp. 242-246 : 242-245

Torrenticola (Torrenticola) ungeri (Szalay, 1927)

( Figs 1–9 )

Material examined: 1 female and 1 male, Russia, North Caucasus , Republic Adygheya , Maykop District , Kurdghips River near farm the Red Bridge, 2 November 2012, leg. M. Shapovalov, A. Motorin and M. Saprykin.

Redescription. Female. Body wide and oval-shaped, frontal edge between setae Fch wide and straight ( Fig. 1 ). Dorsum with main dorsal shield and two pairs of anterior platelets (medial and lateral). Anteromedial platelets separated from dorsal shield, narrow (L/W ratio 3.8) with parallel lateral margins. Anterolateral platelets rather broad (L/W ratio 2.0) with convex inner margins, fused with dorsal shield, but suture line between them present. Dorsal shield wide (L/W ratio 1.22), covering about 4/5 of dorsal surface, secondary sclerotization slightly developed. Glandularia Sci located distant from lateral margins of dorsal shield. Two muscle attachment sites with rough sculpture slightly posterior to glandularia Sci. Setae Fch thicker than others idiosomal setae. Setae Vi located on anteromedial platelets, setae Oi and Hi on anterolateral platelets; Li and Si situated in the zone of secondary sclerotization of dorsal shield; Fch, Fp, Ve, Oe, He, Le, Si and five pairs of slit organs occupy peripheral position on dorsum.

Coxal shield large, covering about 4/5 of ventral area, capitular bay U–shaped ( Fig. 2 ). Suture line between coxae II+III 3.5 times shorter than medial suture line of coxae I. Tips of coxal plates I with 6-8 long, stout setae. Genital field pentagonal in shape with six pairs of subequal acetabula. Glandularia Sce opening at level of posterior margin of genital field, glandularia Pe situated medially to suture line between coxal plates II+III. Fragments of suture lines of coxal plates IV in the medial part directed posteriorly, laterally curved. Excretory pore and setae Ci away from the line of primary sclerotization, and Pi situated close to this line.

Capitulum ( Fig. 3 ) with long rostrum, capitular base with convex ventral margin, rostrum almost twice as short as basic part of capitulum; anterior end of rostrum curved dorsally.

Chelicera ( Fig. 4 ) elongated and slightly thickened proximally; stylet short, crescent, with two rows of fine teeth on concave side.

Pedipalp ( Fig. 5 ) robust; P–1 short, with single dorsodistal setae; P–2 thick, with straight or concave ventral margin, with five dorsal subequal setae, and one further seta laterally at base of the ventrodistal conic projection; P–3 with straight ventral margin, with one short proximal and two long unequal dorsodistal setae), ventral side of P–3 with projection and single seta, the last longer than that of P–2, ventral margin without fine serration; P–4 stout, shorter than P–2, curved distally, with 3-4 small ventrodistal tubercles bearing long, thin unequal setae, proximoventral part of segment with fine serration; P-5 short, its length and height subequal, with single solenidion, with four thin setae and four short terminal spines.

Morphology and chaetotaxy of terminal segments of leg I and IV as illustrated in figures 6 and 7, respectively. All legs without swimming setae. Tarsi of legs II–IV gradually slightly thickened to distal end, their ventral margin straight. Ambulacra with long external and short internal clawlets, ventral margin of blade nearly straight ( Fig. 8 ).

Measurements (n=1). Idiosoma L 685, W 585; anteromedial platelets L 150, W 40; anterolateral platelets L 160, W 80; length of dorsal shield 585, W 485; distance from glandularia Sci to lateral margin of dorsal shield 65; median portion of coxae I 155, length of suture line of coxae II+III 62; genital flap L 150, W 75; capitulum L 335; basal segment of chelicera L 300, cheliceral stylet L 55; pedipalpal segments (P–1–5) L: 42, 102, 63, 93, 20; legs segments L: I–Leg–1–6: 37, 75, 75, 100, 110, 100; II–Leg–1–6: 37,75, 80, 110, 125, 125; III–Leg–1–6: 45, 75, 80, 125, 135, 150; IV–Leg–1–6: 105, 80, 110, 150, 175, 170.

Male. Dorsal surface, gnathosoma and legs of male same as at female. Suture line between coxal plates II+III is twice times shorter than the medial portion of coxal plates I ( Fig. 9 ), genital field roundish.

Measurements (n=1). Idiosoma L 770, W 585; anteromedial platelets 140, W 50; anterolateral platelets L 165, W 75; length of dorsal shield 575, W 475; distance from glandularia Sci to lateral margin of dorsal shield 75; median portion of coxae I 150, length of suture line of coxae II+III 75; genital flap 140, W 75; capitulum L 300; basal segment of chelicera L 310, cheliceral stylet L 55; pedipalpal segments (P–1–5) L: 40, 105, 62, 96, 16; legs segments L: I–Leg–1–6: 37, 75, 87, 105, 110, 100; II–Leg–1–6: 37, 60, 75, 100, 115, 110; III–Leg–1–6: 50, 60, 80, 115, 125, 140; IV–Leg–1–6: 110, 85, 110, 140, 175, 150.

Remarks. The water mite Torrenticola ungeri (Szalay, 1927) includes two subspecies: T. ungeri ungeri (Szalay, 1927) and T. ungeri disparilis (Walter, 1947) . The presented specimens are similar to T. ungeri ungeri although there are some differences in the structure of the pedipalps. P-3 and P- 4 in T. ungeri ungeri are with fine serrations, P- 4 in addition with 6-7 small ventral tubercles bearing fine setae ( Di Sabatino et al. 2010). In the Caucasian specimens P-3 are without fine serrations, and P-4 has 2-4 small ventral tubercles. Lundblad (1956) and Szalay (1964) did not mark the presence of fine serration on P-3 also. Probably, the presence of fine serrations on P-3, and the number of small distoventral tubercles on P- 4 in adults of T. ungeri ungeri varies in various localities.

Habitat. Surface and interstitial waters ( Di Sabatino et al. 2010).

Distribution in Russia. North Caucasus, Republic Adygheya.

Figures

Figure 9. Torrenticola ungeri (Szalay, 1927), male: 9 – ventral view. Scale bar: 200 μm.

Figures 1–2. Torrenticola ungeri (Szalay, 1927), female: 1- dorsal view, 2 - ventral view. Scale bar: 200 μm.

Figures 3–8. Torrenticola ungeri (Szalay, 1927), female: 3 – capitulum, lateral view; 4 – chelicerae, lateral view, 5 – pedipalp; 6 – I-Leg-4-6; 7 – IV-Leg- 4-6; 8 – claw IV. Scale bars: 3–4, 6-7 = 100 μm, 5, 8 = 50 μm.