Oxus reticulatus, Smit, 2011

Smit, H., 2011, New Species Of Water Mites From New Guinea (Acari: Hydrachnidia, Halacaridae), Acarologia 51 (3), pp. 321-345 : 325

Oxus reticulatus n. sp.

( Figure 2 )

Material examined — Holotype male, unnamed creek, forest near UNCEN, Abepura, 2°34.794’ S; 140°39.292’ E, alt. 234 m a.s.l., 31-iii-2010. Paratypes: one male, one female, same data as holotype .

Diagnosis — Coxae with a reticulate pattern; excretory pore on a long platelet; median strip without glandularia.

Description — Male: Idiosoma laterally compressed, 680 (616) long, 308 wide and 456 (429) high. Coxae expanded and occupying most of idiosoma except a narrow median dorsal strip ( Figure 2b ); this dorsal strip without glandularia but with a pair of postocularia on elongated platelets. Tip of first coxal plates with a pair of long, stout setae ( Figure 2a ). Coxal plates with a distinct reticulate pattern, especially visible anteriorly, in ventral view appearing scaly. Second and third coxal plates with a distinct pinnate setae. Eleven pairs of glandularia (sensu Cook 1986) incorporated in the expanded coxal area ( Figure 2c ). Coxae ventrally without a distinct suture line. Genital field with three pairs of acetabula, 110 long and 82 wide. Excretory pore on an elongated platelet. Length of PI-PV: 32, 32, 38, 60, 26; PIV slender ( Figure 2d ). Length of I-Leg-4-6: 80, 84, 82. Length of IV-leg-4-6: 80, 80, 122; distal seta of IV-leg-6 80 long. Claws without a comb. Second, third and fourth legs with numerous swimming setae.

Female: Idiosoma 689 long and 417 wide (width not measured). Morphology as in male. Genital field 108 long. Lengths of PI-PV: 28, 34, 38, 60, 28; palp as in male. Lengths of I-leg-5-6: 80, 87. Lengths of IV-leg-4-6: 76, 116, 122; distal seta of IV-leg-6 72 long. Legs as in male.

Etymology — Named for the reticulated pattern on the coxal area.

Remarks — The combination of coxae with a reticulate pattern, excretory pore on an elongated platelet and a dorsal median strip without glandularia is characteristic for the new species. A number of Australian species and one species from New Guinea have the excretory pore on a platelet (i.e. O. grenada ( Cook, 1986), O. tasmanica ( Cook, 1986), O. neotasmanica ( Cook, 1986), O. zunova ( Cook, 1986) and Oxus michellae (Wiles, 1997)), but in none of these species this platelet is elongated, while the reticulate pattern is absent.

Figures

FIGURE 2: Oxus reticulatus n.sp., holotype male: a – ventral view; b – dorsal view; c – lateral view; d – palp. (Scale bar = 50 µm).