Austraturus crystalensis, 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 : 105

Austraturus crystalensis n.sp.

Figs. 20–24

Type material. HOLOTYPE male, Big Crystal Creek , Paluma Range National Park, Queensland, Australia, 18°58.754'S 146°15.231'E, 21 October 2005 . PARATYPES: 2 females ( QM) , 1 female ( ZMAN), same data as holotype .

Diagnosis. Fourth leg and posteromedial dorsal plate of male unmodified, gonopore of male short, PII high and ventrally with two teeth.

Description. Male: Dorsal and ventral shields present, dorsal furrow complete. Idiosoma ventrally 365 long and 263 wide, dorsally 308 long. Idiosoma colour pale, eyes absent. Dorsum with three pairs of plates and a large posteromedial plate, the latter 196 long and 162 wide, with two shallow concavities. Anterior pair of plates bearing the postocularia.Anterolateral plates each with two pairs of glandularia, posterolateral plates each with one pair of glandularia. Posteromedial plate unmodified, with three pairs of glandularia. Setae of dorsal plates not thickened. First coxal plates extending beyond anterior body margin. Glandularia of fourth coxal plates small, located halfway anterior and posterior margin of fourth coxal plates. Gonopore short and narrow, 27 long. Only a few (approximately six) acetabula visible. Excretory pore terminal. Lengths of PI–PV: 19, 58, 30, 84, 29. PII high with two large teeth ventrally, ventral margin of PIV slightly convex. Lengths of first leg segments not measurable. Lengths of IV-leg-4–6: 74, 79, 76. Fourth leg unmodified. Swimming setae absent. Claws of legs with clawlet, without claw blade.

Female: Dorsal and ventral shields present, dorsal furrow complete. Idiosoma ventrally 373 (340–373) long and 271 (243–267) wide, dorsally 304 (275–308) long. Dorsum as in male, large posteromedial plate 176 long and 154 wide. First coxal plates extending beyond anterior body margin. Glandularia of fourth coxal plates located near anterior margin of fourth coxal plates. Gonopore 45 long. Anterior two pairs of acetabula noticeably larger than others. Most acetabula not visible. Lengths of PI–PV: 18, 60, 33, 84, 28; palp as in male, but PII ventrally with a small third tooth. Lengths of I-leg-4–6: 52, 54, 68. Lengths of IV-leg-4–6: 70, 78, 68. Legs without swimming setae. Claws of legs with clawlet, without claw blade.

Etymology. Named after the type locality.

Remarks. Cook (1986) considered A. concavus Cook an interstitial species, based on its peculiar morphological characters. If correct, the new species described here is the second interstitial species of the genus. It is the least modified species of the genus, without modifications of the posteromedial dorsal plate or the fourth leg of the male. The female can be identified with the shape of the palp. Austraturus projectus Cook also has PII with two teeth, but this species has a much longer PIV.

Figures

Figs 20–24. Austraturus crystalensis n.sp., (20–23) holotype male: (20) ventral view; (21) dorsal view; (22) palp; (23) IV-leg-4–6, scale bars 20–23 = 50 µm. (24) Austraturus crystalensis n.sp., paratype female, ventral view, scale bar = 50 µm.