Atractides thoracatus Koenike, 1898

Smit, Harry, Pesic, Vladimir & Mary-Sasal, Nathalie, 2010, Second contribution to the knowledge of water mites from the Comoros, with the description of one new species (Acari: Hydrachnidia), Zootaxa 2413, pp. 51-60 : 55

Atractides thoracatus Koenike, 1898

( Figs. 3A–C )

Material examined. Comoros, Mayotte: Riv. Djul:mov, downstream, 12°48'19,5"S 45°09'49,7"E, 03-x-2008, 0/1/0 (one I-Leg and one palp missing, mounted).

Morphology. Female. Idiosoma L/W 719/566; integument dorsally smooth. Muscle attachment plates unsclerotized. Coxal field ( Fig. 3A ): slender and longish, mediocaudal margin Cx-1 tongue-shaped, caudal margin Cx-4 oblique, L 306, Cx-3 W 375, mL 123, lL 228. Palp ( Fig. 3B ): total L 271, dL and %L (in parentheses): P-1, 29 (10.7); P-2, 58 (21.4); P-3, 59 (21.8); P-4, 91 (33.6); P-5, 34 (12.6); L P-2/P-4 ratio 0.64; P-2 ventral margin straight, sword seta of P-4 approaching to distoventral hair. Genital field ( Fig. 3A ): L 159, W 152, pregenital sclerite large, W 86, gonopore extending far beyond the anterior margin of the genital plates, genital plates triangular-shaped, L/W 75-77/40, L Ac-1-3: 24-27, 25-28, 27-28. Excretory pore with sclerite ring; Vgl-1 not fused to Vgl-2.

I-Leg ( Fig. 3C ): I-Leg-5 rather long, S-1 and -2 similar in dimensions, stocky, blunt, close together; I-Leg- 6 short, strongly curved, basally thickened and distally gradually narrowed; I-Leg-5 dL 130, vL 115, dL/vL ratio 1.13, HB 42, dL/HB ratio 3.1, S-1 L 52, S-2 L 51, distance of sword setae at I-Leg-5 4, L ratio S-1/2 1.02; I-Leg-6 L 79, HB 18, L/HB ratio 4.4; L ratio I-Leg-5/6 1.66.

Remarks. The specimen reported here agrees well with the redescription given by K.O. Viets (1962) for specimens from Nossi-Bé, Madagascar.

Distribution. Madagascar. New for the Comoros.

Figures

FIGURE 3 A – C. Atractides thoracatus Koenike, female: A = coxal and genital field; B = palp; C = I-L- 5 - 6. Scale bars = 100 μm.