Atractides Koch, 1836

Martin, Peter, 2006, On the morphology and classification of larval water mites (Hydrachnidia, Acari) from springs in Luxembourg, Zootaxa 1138, pp. 1-44 : 26-27

Genus Atractides Koch, 1836

Diagnosis: Character states as given for the family. Differential characters to separate Records ( Table 2): Benthos samples at nine spring sites in Gutland, 51 individuals ( Gerecke et al. 2005). E1 129, E7 54 larvae, parasitic on chironomids. 10 larvae were bred from a female from the spring site Lux Qu19 (E1). Attribution by rearing.

Description (unless otherwise indicated, n = 5): Idiosoma moderately elongated ( Figs. 44, 45 ). Length/width of idiosoma 225–230 (227)/133–145 (140).

Dorsal idiosoma ( Fig. 44 ): Dp relatively narrow and slightly tapered posteriorly, largest width in the posterior third of the plate, length/width 243–250 (247)/130–138 (134), Mp2­Amdp 38–42 (40), Mp1­Mp1 46–50 (48), Mp2­Mp2 38–40 (39), Lp1­Lp1 34–36 (35), Lp2­Lp2 70–73 (72), Mp1­Lp 1 12–14 (13), Mp2­Lp 2 17–18 (17), Mp1­Lp 2 20–23 (22), Lp1­Lp2 32–34 (33), Mp 1 18–22 (20), Mp 2 19–22 (21), Lp1 47–65 (54), Lp2 85–91 (89), Hu 57–67 (60), Mh1 95–99 (97), Mh2 88–96 (93), Mh3 43–46 (44), Mh4 37– 42 (40), Lh1 43–52 (47), Lh2 44–48 (46), Lh3 45–48 (46).

Ventral idiosoma ( Fig. 45 ): Expp relatively large (in contrast to the other Atractides species reported here). Length CX­I­III (from the median gnathosomal bay to the posterior end of CX­I­III) 180–190 (186), width CX­I­III 75–79 (77), common median length of both CX­I­III 160–165 (164), maximum length of CX­I­III 225–230 (229), C1­C2 49–53 (51), C1­Mmcp 15–17 (16), C4­Pmcp 97–102 (100), C1­C4 53–59 (55), C1 55–66 (60), C2 47–52 (49), C3 50–63 (56), C4 95–100 (97), length/width Expp 44–46 (45)/79–87 (81), E1­ E 1 12 –16 (13), E2­ E 2 22 –23 (22), E1 4 –6 (5), E2 6 –8 (7), V 1 31–35 (32), V2 34 – 37 (36), V3 45 –51 (48), V4 170–180 (176), V1­V 1 23–24 (24), V2­V2 65 –70 (67), V3­V3 79 –82 (80), V4­V4 58 –66 (61), V1­V 2 25–28 (26), length/width of projecting base of V 4 17–20 (18)/11–11 (11).

Gnathosoma: Base 72–76 (73), chelicera ( Fig. 46 ) 67–72 (69), chela 18–19 (18), length/width P1+ 2 31–34 (33)/29–33 (31), P 3 19–21 (20)/20–22 (21), length claw 11–13 (12), long seta on P3 76–82 (79).

Legs: Leg I ( Fig. 47 ): Total length 189–199 (194), length/height I­L1 (1se) 30–32 (31)/18–20 (19), I­L2 (7se) 37–39 (38)/17–18 (17), I­L3 (7se) 32–35 (33)/16–17 (17), I­L4 (4se, 1so, 1eu) 40–41 (40)/17–18 (17), I­L5 (12se, 1so, 2eu) 50–52 (51)/14–15 (14).

Leg II ( Fig. 48 ): Total length 205–214 (209), length/height II­L1 (1se) 31–32 (32)/19– 21 (20), II­L2 (7se) 38–39 (38)/18–19 (18), II­L3 (4se, 1 so) 33–35 (34)/16–18 (17), II­L4 (9se, 1 so) 43–45 (44)/16–18 (16), II­L5 (12se, 1so) 60–63 (61)/12–14 (13).

Leg III ( Fig. 49 ): Total length 241–252 (247), length/height III­L1 (1se) 38–40 (39)/ 16–18 (17), III­L2 (6se) 40–43 (42)/16–18 (17), III­L3 (4se, 1so) 41–42 (41)/15–16 (16), III­L4 (8se, 1so) 56–58 (57)/16–17 (17), III­L5 (10se) 66–69 (68)/13–14 (14).

Diagnostic characters of larvae: To date, the larva of Atractides fonticolus has remained undescribed. It differs from the other Atractides larvae here with respect to leg length, length of Dp and width of Expp.

Figures

FIGURES 44 – 46. Atractides fonticolus (original). Fig. 44: dorsal idiosoma, Fig. 45: ventral idiosoma, Fig. 46: chelicera. Scale bars: 44, 45 100 µm, 46 50 µm.

FIGURES 47 – 49. Atractides fonticolus (original). Fig. 47: I­L, Fig. 48: II­L, Fig. 49: III­L. Scale bar: 100 µm.