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). E 1 129, E 7 54 larvae, parasitic on chironomids. 10 larvae were bred from a female from the spring site Lux Qu 19 (E 1). 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), Mp 2 ­Amdp 38–42 (40), Mp 1 ­Mp 1 46–50 (48), Mp 2 ­Mp 2 38–40 (39), Lp 1 ­Lp 1 34–36 (35), Lp 2 ­Lp 2 70–73 (72), Mp 1 ­Lp 1 12–14 (13), Mp 2 ­Lp 2 17–18 (17), Mp 1 ­Lp 2 20–23 (22), Lp 1 ­Lp 2 32–34 (33), Mp 1 18–22 (20), Mp 2 19–22 (21), Lp 1 47–65 (54), Lp 2 85–91 (89), Hu 57–67 (60), Mh 1 95–99 (97), Mh 2 88–96 (93), Mh 3 43–46 (44), Mh 4 37– 42 (40), Lh 1 43–52 (47), Lh 2 44–48 (46), Lh 3 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), C 1 ­C 2 49–53 (51), C 1 ­Mmcp 15–17 (16), C 4 ­Pmcp 97–102 (100), C 1 ­C 4 53–59 (55), C 1 55–66 (60), C 2 47–52 (49), C 3 50–63 (56), C 4 95–100 (97), length/width Expp 44–46 (45)/ 79–87 (81), E 1 ­ E 1 12 –16 (13), E 2 ­ E 2 22 –23 (22), E 1 4 –6 (5), E 2 6 –8 (7), V 1 31–35 (32), V 2 34 – 37 (36), V 3 45 –51 (48), V 4 170–180 (176), V 1 ­V 1 23–24 (24), V 2 ­V 2 65 –70 (67), V 3 ­V 3 79 –82 (80), V 4 ­V 4 58 –66 (61), V 1 ­V 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 P 1 + 2 31–34 (33)/ 29–33 (31), P 3 19–21 (20)/ 20–22 (21), length claw 11–13 (12), long seta on P 3 76–82 (79).

Legs: Leg I ( Fig. 47 ): Total length 189–199 (194), length/height I­L 1 (1 se) 30–32 (31)/ 18–20 (19), I­L 2 (7 se) 37–39 (38)/ 17–18 (17), I­L 3 (7 se) 32–35 (33)/ 16–17 (17), I­L 4 (4 se, 1 so, 1 eu) 40–41 (40)/ 17–18 (17), I­L 5 (12 se, 1 so, 2 eu) 50–52 (51)/ 14–15 (14).

Leg II ( Fig. 48 ): Total length 205–214 (209), length/height II­L 1 (1 se) 31–32 (32)/ 19– 21 (20), II­L 2 (7 se) 38–39 (38)/ 18–19 (18), II­L 3 (4 se, 1 so) 33–35 (34)/ 16–18 (17), II­L 4 (9 se, 1 so) 43–45 (44)/ 16–18 (16), II­L 5 (12 se, 1 so) 60–63 (61)/ 12–14 (13).

Leg III ( Fig. 49 ): Total length 241–252 (247), length/height III­L 1 (1 se) 38–40 (39)/ 16–18 (17), III­L 2 (6 se) 40–43 (42)/ 16–18 (17), III­L 3 (4 se, 1 so) 41–42 (41)/ 15–16 (16), III­L 4 (8 se, 1 so) 56–58 (57)/ 16–17 (17), III­L 5 (10 se) 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.