Limnochares danielei Gerecke & Smit

Davids, Kees, Sabatino, Antonio Di, Gerecke, Reinhard, Gledhill, Terence & Smit, Harry, 2005, On the taxonomy of water mites (Acari: Hydrachnidia) described from the Palaearctic, part 1: Hydrachnidae, Limnocharidae and Eylaidae, Zootaxa 1061, pp. 36-64 : 58-59

Limnochares danielei Gerecke & Smit , sp. nov.

Type series: Holotype male, Cyprus, South of Prodromos, unnamed creek at crossing with road E 804, 22.04.2002 leg. H. Smit, slide mounted together with a paratype male in Hoyers medium ( ZMAN); paratypes (same site and date): one male, slide mounted together with the holotype, one male, two females, slide mounted in Hoyers medium; three males, five females undissected, in Koenikes fluid ( ZMAN).

Diagnosis: Idiosoma L 1500–2000, dorsum bearing five pairs of rod­shaped sclerites and, in the posterior part, one unpaired transverse or triangular sclerite; frontal shield short and robust (L/H ratio 1.9–2.1); Cx­1+2 ( Fig. 3 E) enlarged (L/ W 1.3 –1.6), anterolateral edge with a digitiform, densely setose extension, coxal setae rather long; genital field ( Fig. 3 F) with 33–44 pairs of acetabula; genital setae in both sexes not arranged in groups; excretory pore surrounded by a sclerotized ring; palp ( Fig. 2 G) five­segmented with a relatively long P­4 (L 25, L ratio P­2/P­ 4 in females 1.8, in males 2.2).

Description: General morphology as in L. azubi , but all specimens with a sclerotized ring surrounding the excretory pore (if no details are given, morphology as described for L. azubi ).

Males (n = 2): Idiosoma L 1600; frontal sclerite L/W 250–290/135–140; anterodorsal sclerites L 120–150, 190–200; posterodorsal sclerite diameter 60–100; Cx­1 maximum L/ anterior margin W 290/180–190 (1.5–1.6); Cx­3/4 maximum L/anterior W (excluding the subcutaneous apodemes) 370–385/190–195 (2.0); leg IV measurements (L/H) of one paratype: IV­L­4 175/55 (3.2), IV­L­5 200/55 (3.6), IV­L­6 190/50 (3.8); Ac number 70–78, genital setae number 22–26; gnathosoma L 210–240, H 130, W 165, mouth disc diameter 55–60; chelicera basal segment L/H 210/45, claw L 32 (L/H ratio 5.4, basal segment/claw L ratio 6.6); palp segments L/H P­ 1 10/25, P­2 55/40, P­3 40/35, P­ 4 25/25, P­ 5 25/9, total L 155.

Females (n = 2): Idiosoma L 1500–2000; frontal sclerite L/W 300–310/150–160; anterodorsal sclerites L 115–185, 105–165; Cx­1 maximum L/anterior margin W 310–335/205–230 (1.5); Cx­3/4 maximum L/anterior W (excluding the subcutaneous apodemes) 400–460/205–230 (2.0); leg IV measurements (L/H) of one paratype: IV­L­4 200/70 (2.9), IV­L­5 230/60 (3.8), IV­L­6 220/60 (3.7); Ac number 87–89, genital setae number 19–24; gnathosoma L 250–275, H 140, W 170, mouth disc diameter 65; chelicera basal segment L 250, claw L 35 (basal segment/claw L ratio 7.2); palp segments L/H P­ 1 12/27, P­2 62/42, P­3 48/37, P­ 4 35/26, P­ 5 27/10, total L 184.

Deutonymph: Unknown.

Dervivatio nominis: Named after our friend and colleague Daniele Benfatti (1957–2004).

Discussion: This species is obviously closely related to L. azubi . Common characters that separate both species from L. aquatica are the shape and arrangement of the dorsal sclerites, the presence of a setose anterior extension of Cx­1, and the relatively low number of acetabula. Limnochares danielei differs from L. azubi in the relatively enlarged anterior coxal plates (L/W <1.7, in L. azubi 1.7–2.1) with longer setae, and a longer, more inflated P­4 (L 25–35, in L. azubi 14–20). Furthermore, all specimens have the excretory pore surrounded by a sclerotized ring, while in L. azubi a structure of this type was found only in one exceptional case, presumably a specimen that had undergone an additional adult moult ­ this specimen differs in having a very high number of 155 acetabula whereas all other specimens of both L. azubi and L. danielei have fewer (<100). Limnochares danielei , like L. azubi , differs from the American species, L. anomala , in the presence of a setose projection on Cx­1.

Figures

FIGURE 3. A Limnochares aquatica Linnaeus male (Sardinia), anterior coxae; B – D Limnochares azubi Gerecke sp. nov, paratype male; B gnathosoma, ventral view; C I­L­ 4 ­ 6; D IV­L­ 4 ­ 6. E, F Limnochares danielei Gerecke & Smit sp. nov., female; E anterior coxae, F genital field. Bars = 100 µm.

FIGURE 2. A – F Limnochares azubi Gerecke sp. nov. A, B " hypertrophic " female from Morocco; A dorsum; B genital field and excretory pore; C – E paratype male; C gnathosoma lateral view, D chelicera, E palp; F paratype male palp. G Limnochares danielei Gerecke & Smit sp. nov., female palp. Bars = 100 µm.