Partidomomonia tertia, Smit, 2007

Smit, Harry, 2007, New Records of Hyporheic Water Mites from Australia, with a Description of Two New Genera and Ten New Species (Acari: Hydrachnidia), Records of the Australian Museum 59 (2), pp. 97-116 : 110-112

Partidomomonia tertia n.sp.

Figs. 42–46

Type material. HOLOTYPE male, Dalrymple Creek , Goomburra Forest Reserve, Queensland, Australia, 27°58.781'S 152°20.621 E; alt. 690 m, 17 November 2003 ( QM) . PARATYPES: 1 male ( QM) , 1 male ( ZMAN), same data as holotype ; 1 male ( ZMAN), same location as holotype, 5 November 2005 .

Diagnosis. Lateroglandularia 5 fused with large posterior dorsal plate.

Description. Male: Colour pale. Dorsal and ventral shields present. Idiosoma ventrally 725 (697–770) long and 591 (591–648) wide, dorsally 648 (616–697) long. Dorsum with one posterior large plate with three pairs of setae lacking the associated glandularia. Anteriorly two pairs of large plates, the most anterior plate with the postocularia, the posterior of these two plates with a pair of setae without the associated glandularia. Laterally of these large plates three pairs of glandularia on smaller plates (dg2, lg3 and lg4 sensu Harvey, 1990a). Ventral shield entire; capitular bay deep and rounded basally. Suture lines of coxae incomplete and obliterated. First coxae extending beyond anterior body margin. Gonopore with three pairs of acetabula lying within the gonopore, acetabula not on platelets. Posterior two acetabula closer to each other than anterior acetabula. Gonopore 88 long, anteriorly rounded. Excretory pore close to posterior idiosoma margin. Lengths of PI–PV: 23, 62, 33, 71, 26 (without large terminal seta). Palp typical, PIV ventrally with one large and one small pointed seta both on a small tubercle; PV with a large terminal pointed seta. Lengths of I-leg-4–6: 94, 308, 198. I-leg-6 typical for the family Momoniidae , with I-leg-5 elongated and I-leg-6 bifurcate distally with a slender and downwards pointed claw. Lengths of IV-leg-4–6: 157, 214, 157. Claws of legs II-IV with large clawlet and small claw blade.

Female: Unknown.

Etymology. This is the third species of the genus from Australia.

Remarks. The new species differs from the two known Australian species and the one known species from New Zealand in the lateroglandularia 5 which are fused with the large posterior dorsal plate. In all three other species the lateroglandularia are lying on separate platelets. Moreover, P. blythi Harvey and P. polyplacophora Cook have a much more elongated idiosoma shape. The two known Australian species have been found in Victoria. Cook (1986) found a deutonymph in Queensland, but left it unnamed. I-leg-6 of this nymph is much shorter than in the new species, so very likely it cannot be assigned to the new species.

Figures

Figs 42–46. Partidomomonia tertia n.sp., holotype male, (42) dorsal view; (43) ventral view; (44) genital field; (45) palp; (46) I-leg-5–6. Scale bars 42–43 = 200 µm, 44–46 = 50 µm.