Arrenurus (Truncaturus) novaecambricus, Smit, Harry, 2010

Smit, Harry, 2010, Australian Arrenurus (Acari, Hydrachnidia) with the description of eleven new species, Zootaxa 2541, pp. 1-26 : 25

Arrenurus (Truncaturus) novaecambricus n. sp.

( Figs. 15A–D )

Material examined. Holotype male, Small lake near Diggers Creek, Mt. Kosciuszko NP, New South Wales, Australia, 36° 21.589 S 148° 29.248 E, alt. 1511 m a.s.l., 5 December 2003 (AMS). Paratypes: 1/5/0 (AMS), 1/4/0 ( ZMAN), same data as holotype.

Diagnosis. Idiosoma of male little modified, without cauda or particular appendages.

Description. Male: Idiosoma yellowish brown, 907 (850–871) long and 713 (697) wide. Idiosoma little modified, anterior margin rounded to slightly indented, posteriorly with a shallow indentation ( Fig. 15A ). Dorsal shield incomplete, 543 (535–543) wide. Anterior coxal plates not extending to anterior idiosoma margin. Gonopore 62 long. Genital field 421 wide, genital plates short and broad, slightly curved ( Fig. 15B ). Lengths of PI-PV: 38, 96, 80, 90, 40. PII medially with three setae, PIV stocky ( Fig. 15C ). Lengths of I-leg-4- 6: 158, 158, 194; I-leg-6 with numerous thin, long setae. Lengths of IV-leg-4-6: 142, 170, 170. IV-leg-4 without spur, third and fourth legs with numerous swimming setae.

Female: Idiosoma 1094 (1037–1166) long and 879 (867–932) wide, anteriorly straight, posteriorly without posterolateral corners, in some specimens slightly truncated posteriorly. Idiosoma colour as in male. Dorsal shield complete, 851 (810–903) long and 692 (680–770) wide. Medial margin of third+ fourth coxal plates slightly sloping, medial distance of third + fourth coxal plates longer than one genital valve. Medial margin of fourth coxal plates a little bit longer than medial margin of third coxal plates. Gonopore 134 long and 144 wide. Genital field 445 wide, genital plates short and broad, sloping posteriorly ( Fig. 15D ). Lengths of PI-PV: 40, 88, 72, 96, 50; palp as in male. Lengths of I-leg-4-6: 150, 146, 142. Lengths of IV-leg-4-6: 190, 194, 194. Third and fourth legs with numerous swimming setae.

Etymology. Named after the state of the type locality, New (South) Wales.

Remarks. Previously only three species of the subgenus Truncaturus were known from Australia. The new species is somewhat similar to A. tasmanicus Lundblad , but the latter species is smaller and has a more elongate idiosoma. Arrenurus novaehollandiae Lundblad is much smaller (around 640), and has the posterior idiosoma margin with three shallow indentations. Arrenurus haswelli Cook and A. indentatus n. sp. have the posterior margin with a median cleft.

Figures

FIGURE 15 A – D. Arrenurus novaecambricus n. sp., (A – C holotype male, D paratype female): A = dorsal view; B = ventral view; C = palp; D = ventral view. Scale bars A – B, D = 200 µm; C = 50 µm.