Arrenurus (Arrenurus) trichophorus Daday, 1905

Ferradás, Rosso & Beatriz, 2006, New species and records of Arrenurus from the Paraná river, Argentina (Acari: Parasitengona: Arrenuridae), Zootaxa 1208, pp. 25-35 : 31-34

Arrenurus (Arrenurus) trichophorus Daday, 1905

Arrhenurus trichophorus Daday, 1905: 338 ; typical area, Tuyutí, Villarrica, Paraguay; Arrenurus (s. str.) trichophorus Lundblad, 1944: 18 ; Viets, 1978: 57; Rosso de Ferradás & Fernández, 2005: 191.

Description

Males: Body, anterior section oval in shape, with the eyes located on a pair of protuberances; length, including pygal lobes, 876–950 (1175); width 731–801 (948); appendix, marked by an angle of the ventral shield, length 206–289; width 529–611; dorsal furrow reaches the ventral surface; second pair of dorsal glands on protuberances joined only at their base; length of the dorsal shield to the posterior end 710; width 512; petiole, dorsal length 116–153 (123); width 148–206; straight sides, slightly narrower at the base, the center being higher and larger and the borders thinner and translucent ( Fig. 12 ); coxae, length between the anterior end of Cx­I and the posterior border of Cx­IV: 562–664 (537); width between the left and right articular apophyses of IV­Leg: 826–859 (950); genital field reaches the border of the body, width: 545–562 (619) ( Fig. 12 ); length of the gonopore 58–66 (50); capitulum, ventral length 185–202 (212); chelicera 226–236 (210); dorsal lengths of the palpal segments, P­I, 45–53 (35); P­II, 103–124 (107); P­III, 82–103 (72); P­IV, 164–214 (134); P­V, 74–78 (66); all palpal hairs are bipectinate, except for the internal hair of P­III ( Fig. 13 ); dorsal lengths of the distal segments of the first leg: I­Leg­4, 170–177 (164); I­Leg­5, 160–172 (148); I­Leg­6, 150–168 (134); dorsal lengths of the distal segments of the fourth leg: IV­Leg­4, 242–267 (222); spur, 70–82 (62); IV­ Leg­5, 177–185 (185); IV­Leg­6, 201–205 (205); I­Leg­6, covered with long, thin hair ( Fig. 14 ) IV­Leg­3 with 8–10 swimming hairs (s.h.) (11–14); IV­Leg­4 with 7–11 s.h. (14), its distal end a brush of 4 long, fine, but non­swimming hairs ( Fig. 15 ); IV­Leg­5 with 11–13 s.h. (13).

Female: Body rounded in shape, slightly projected forward; length 793–950; width 628–892; full dorsal furrow; dorsal shield with 3 pairs of glandularia; length 575–611; width 496–624; Cx­I and Cx­II with the sharpened anterior ends ( Fig. 16 ); length between the anterior end of Cx­I to the posterior border of Cx­IV 388–562; width between the articular apophysis of IV­Leg 496–706; genital field located posterolaterally with regard to the genital flaps ( Fig. 16 ); width of the genital field 380–432; genital flaps, length 140–143; width 140–140; morphology and chaetotaxy of the palpi as in the males; length of the dorsal border of the palpal segments, P­I: 42–45; P­II: 112–138; P­III: 68–72; P­IV: 134–196; P­V: 70–82; legs, distal border of the segments, I­Leg­4: 134–142; I­Leg­5: 110–127; I­Leg­6: 103–109 ( Fig. 17 ); IV­Leg­4: 144–168; IV­Leg­5: 134–147; IV­Leg­6: 113–126; IV­Leg­3 with 9 s.h.; IV­Leg­4 with 7–7 s.h.; IV­Leg­5 with 7–8 s.h. ( Fig. 18 ). Material studied

1 % and 2 Ψ: ARGENTINA, province of Buenos Aires, Campana county, Otamendi, small pond communicated with the Paraná de las Palmas, M. Archangelsky collection, 17­ XII­1987; 2 % and 4 Ψ: the same references and col., 16­II­1988; 4 % and 3 Ψ, the same references and col., 27­VI­1988, the entire material deposited in C.C.D.A.I..

A male from Paraguay, Lundblad Collection, " Riksmuseum ", Stockholm, Sweden whose label has the following data: 2227 Plesiotyp; Arrenurus trichophorus Daday ; Paraguay, Villarrica. Tujuti. Sumpfbach; 23­12­1937; F.H. Schade leg..

Comments

The males from Paraná are smaller than the specimen from the Lundblad Collection (plesiotype), but among the Argentinian specimens studied, the palps and legs have variations in width that reach greater values than those of the Paraguayan specimen. In the A. trichophorus from the Paraná river, the central glands of the dorsal shield are located on marked protuberances; I also found variations in the number and types of hair on the internal face of P­II relative to the revised Lundblad specimen. The description of the female of this species was carried out concisely by Daday (1905) but later was not included in the revisions of Daday’s species carried out by Lundblad (1930 and 1944).

The small pond mentioned above contained a diversity of aquatic vegetation ( Lemnaceae , Araceae and Potamogetonaceae ) and the water mite fauna included species of Mamersellides (Anisitsiellidae) , Limnesia , Koenikea, Arrenurus (Megaluracarus) and A. (Arrenuropsides).

Figures

FIGURES 12 – 18. Arrenurus (A.) trichophorus Daday. Male, 12, ventral view (scale line = 78 µm); 13, palp, lateral view (scale line = 30 µm); 14, I­leg­ 5 y 6 (scale line = 25 µm); 15, IV­leg­ 4 ­ 6 (scale = 30 µm). Female, 16, ventral view (scale line = 65 µm); 17, I­leg­ 4 ­ 6 (scale line = 22 µm); 18, IV­leg­ 4 ­ 6 (scale line = 21 µm).