Arrenurus (Truncaturus) indicus Smit & Pesic

Smit, Harry & Pesic, Vladimir, 2008, New records of the water mite genus Arrenurus from India, with the description of one new species (Acari: Hydrachnidia: Arrenuridae), Zootaxa 1894, pp. 53-58 : 56

Arrenurus (Truncaturus) indicus Smit & Pesic n. sp.

( Figs. 5–10 )

Material examined: Holotype male, Mahananda River, Jadavnagar of Aiho Village, Malda district, West Bengal, India, 25 May 2007, leg. Chatterjee ( ZMAN). Paratypes: 2 females, same data as holotype ( ZMAN).

Diagnosis. Body gradually tapering posteriorly, with a wide indentation posteriorly.

Description. Male: Idiosoma greenish, 770 long and 454 wide, gradually tapering posteriorly. Dorsal shield incomplete, none of the dorsal glandularia on humps. Posterior idiosoma margin with a wide indentation; just anterior of posterior idiosoma margin a pair of small lateral humps. Posterior of glandularia D4 (see Wiles 1997) a pair of short, bifid setae. In lateral view a small, hyaline rudimentary petiole is visible (see arrow). Anterior coxae extending just beyond anterior idiosoma margin. Posterior margin of fourth coxae sloping to lateral idiosoma margin. Genital plates narrow, extending to lateral idiosoma margin. Lengths of PI–PV: 26, 66, 44, 66, 34. PII with three anteromedial setae and more dorsally another seta; PIV stocky. Lengths of I-leg-4-6: 112, 112, 90. Lengths of IV-leg-4-6: 124, 163, 148; IV-leg-4 with a long spur. Legs II–IV with numerous swimming setae.

Female: Idiosoma greenish-brownish, 1005 (910) long and 786 (761) wide. Dorsal shield incomplete. Posterolateral corners of idiosoma absent. Coxal field small, covering less than half of ventrum. Medial margin of fourth coxa larger than medial margin of third coxae. Medial distance of third and fourth coxae larger than width of one gonopore valve. Structure of gonopore not visible due to fixation in ethanol. Length of PI– PV: 34, 66, 52, 88, 46; palp as in male. Length of I-leg-4-6: 128, 120, 108. length of IV-leg-4-6: 175, 146, 120. Legs II–IV with numerous swimming setae.

Remarks. Few Truncaturus species are known from India or other parts of Asia, and in males none has the indentation on the posterior margin of the idiosoma.

Figures

FIGURES 5 – 10. Arrenurus (Truncaturus) indicus Smit & Pesic n. sp. (5 – 9 = male, 10 = female): male: 5 = idiosoma, dorsal view; 6 = idiosoma, ventral view; 7 = idiosoma, lateral view; 8 = palp; 9 = posterior part of dorsum; 10 = idiosoma, ventral view. Scale bars: 5 – 6, 10 = 200 μm, 7 – 9 = 50 μm.