Thoracophoracarus cooki, Gerecke, 2009

Gerecke, Reinhard, 2009, Revisional studies on Thoracophoracarus K. Viets, 1914 (Arachnida, Acari, Hydrachnidia, Arrenuridae), Zoosystema 31 (1), pp. 127-145 : 138-141

publication ID	https://doi.org/ 10.5252/z2009n1a7
persistent identifier	https://treatment.plazi.org/id/145F87A3-8247-FF85-349A-D3F7FE50FB7C
treatment provided by	Marcus
scientific name	Thoracophoracarus cooki
status	sp. nov.

Treatment

Thoracophoracarus (s.s.) cooki n. sp. ( Figs 7 View FIG ; 8 View FIG )

TYPE MATERIAL. — Holotype: Madagascar, MD 014, Anjozorobe (Antananarivo), Ravoandrina, left affluent of riv. Ampanakamonty upstream from MD 013, draining a forest clearing, 1230 m, 24.VII.2001, 15.4°C, 0.091 mS/cm, ♂ ( MNHN Ac1118).

Paratypes: same site and date, 1 ♂ ( MNHN Ac 1119) ; 2 ♀♀ ( MNHN Ac 1120) ; 1 deutonymph ( MNHN Ac 1121). — MD 154a, Joffreville (M. d’Ambre, Antsiranana), R. de Manques in Reserve Fontenay, 550 m, 17.XI.2001, 21.9°C, 0.025 mS/cm, 1 ♀ in liquid (coll. Gerecke, Tübingen). — MD 154d, as 154a, 1 juvenile ♂ in liquid (coll. Gerecke, Tübingen). — MD 159a, same area, R. Antomboka between station forestière and cascade, 950 m, 19.XI.2001, 19.7°C, 0.018 mS/cm, 1 ♀ (coll. Gerecke, Tübingen). — MD 160, same area, riparian springs at right border of R. Antomboka downstream sacred cascade, 1000 m, 19.XI.2001, 18.0°C, 0.020 mS/cm, 1 ♂, 1 ♀ (coll. Gerecke, Tübingen). — MD 164, same area, riparian springs at R. de Manques in Reserve Fontenay, 580 m, 20.XI.2001, 21.0°C, 0.031 mS/cm, 1 ♂, 1 deutonymph (coll. Gerecke, Tübingen). — MD 165, same area, R. Antomboka downstr. large cascade, 850 m, 21.XI.2001, 20.0°C, 0.020 mS/cm, 1 ♂ mounted for SEM investigation, 1♀ in liquid (coll. Gerecke, Tübingen) .

ETYMOLOGY. — This species is dedicated to Dave Cook who generously made possible the investigation of the water mite fauna of Madagascar and continuously supports the author’s research with helpful suggestions and encouragement.

DESCRIPTION Gnathosomal bay V-shaped, a bluntly pointed extension of the frontal idiosoma dorsally covering the gnathosoma insertion ( Fig. 7B, D View FIG ). Acetabular fields a little wider than long, with straight anterior and rounded latero-caudal margins, bearing 130- 160 acetabula each. In a juvenile male, integument between acetabula with porosity made up of fine slits; these pores mediocaudally continuing in a narrow medial line directed to the gonopore. Palp ( Fig. 7C View FIG ) P-2 with 2 or 3 dorsal and 2 mediodistal setae; P-3 with 2 setae, 1 long and fine medioproximally, 1 stronger and shorter laterodistally; P-4 L/H 1.3, maximum H proximally,with rather long mediodistal seta; P-5 stout. Male gonopore flanked by a pair of step-like extensions.

Male ( Figs 6 View FIG A-C; 8): idiosoma L/W 750/600-630 (slightly sclerotized juvenile 550/510), W Cx-4-tips 665-670 (slightly sclerotized juvenile 540), acetabular field L/W 125/180. Palp measurements (L/H): P-1 45/50, P-2 120/80, P-3 70/70, P-4 80/60, P-5 45/25. Leg measurements (L/H, segments 1-6): I-L 60/50, 60/45, 75/50, 95/50, 110/50, 145/40; II-L 60/52, 70/50, 90/50, 115/52, 135/52, 160/45; III-L -/-, 85/50, 198/50, 110/55, 140/55, 145/38; IV-L 110/72, 133/56, 125/55, 160/50, 145/40, 140/35. Swimming setae numbers (anterior/posterior):I-L-2 2/0, I-L-3 2/0, I-L-4 0/2, I-L-5 0/2; II-L-2 2/0, II- L-3 2/1, II-L-4 0/4, II-L-5 0/4; III-L-2 4/0, III-L-3 3/3, III-L-4 0/7, III-L-5 0/6; IV-L-2 8/0, IV-L-3 5/4, IV-L-4 8/8, IV-L-5 1/5.

Female ( Fig. 7D View FIG ): idiosoma L/W 690-950/580- 780, W Cx-4-tips 580-760, genital field L/W 50/480. Palp measurements (L/H): P-1 45/50, P-2 130/90, P-3 76/75, P-4 104/63, P-5 50/26. Leg measurements (L/H, segments 1-6): IV-L 120/80, 120/60, 135/55, 175/52, 165/45, 155/38.

REMARKS

In comparison with the other species of the group, T. cooki n. sp. is characteristic in the combination of a V-shaped gnathosomal bay, acetabular fields little wider than long and with more than 100 + 100 acetabula, rather wide step-like extensions in the male genital area, P-2 with only two mediodistal setae, and stout P-4 and P-5.