Hydrodroma wilesi Pesic & Smit, 2007, sp. nov.

Hydrodroma wilesi sp. nov.

(Figs. 1 – 6; Tables 1 – 2)

Type series: Holotype: female, dissected and slide mounted in Hoyer's fluid, NORTHERN TERRITORY, Kakadu National Park, Helocrene near Gunlom Plunge Pool, 30.ix.2005, 13° 25.17 S 132° 24.989 E (NTM). Paratypes: one female (NTM), same data as holotype; Outlet Upper Pool, Edith Falls, Katherine Gorge NP, 30.vii.1994, two males (ZMAN, MNHP), one of them dissected and slide mounted in Hoyer's fluid.

Diagnosis: Characters of the genus Hydrodroma; the basic shape and setation of coxae, genital field and palp are similar to those found in H. torrenticola; 1 – 3 rather short swimming setae on anterior surface on III- L-5, number of swimming setae on III-L-4 1 – 2, on IV-L-5a 2 – 3 and on IV-L-5p 1, swimming setae are absent on the anterior surface of IV-L-5.

Description: Female (holotype, in parentheses some data for paratype): Length of idiosoma 1006 (1000), width 844 (831). Total number of coxal setae is 35 on coxae 1, 35 – 36 on coxae 2, 27 on coxae 3, 22 on coxae 4. Further details of genital plate morphology (Fig. 2) are given in Table 1. Gnathosoma: capitulum (Fig. 5) 182 in length; chelicera total length 250, claw 50 in length. Palps without diagnostic features, for chaetotaxy of the palp see Fig. 4 (measurements in Table 1). Number of swimming setae on legs are presented in Table 2. Swimming setae on anterior surface on III-L-5 rather short.

Male: Length of idiosoma 1180, width 675. Total number of coxal setae varies between 31 – 35 on coxae 1, 37 – 38 on coxae 2, 27 – 28 on coxae 3, 21 – 22 on coxae 4. Further details of genital plate morphology (Fig. 3) are given in Table 1. Gnathosoma: capitulum 172 in length; chelicerae total length 170, claw 35 in length. Palps without diagnostic features, for measurements of the palp see Table 1. Number of swimming setae on legs are presented in Table 2. Swimming setae on anterior surface on III-L-5 rather short.

H. w ilesi

Male (n=2) Female (n=2)

II-L-5 posterior 0 0

III-L-4 posterior 2 1–2 III-L-5 posterior 1–2 rather short 1–3 rather short IV-L-4 anterior 2–3 2–3 IV-L-4 posterior 3–4 2–3 IV-L-5 anterior 0 0

IV-L-5 posterior 1 1

Remarks: Hydrodroma wilesi sp. nov. is most similar to H. tonapii Cook (India) and H. reinhardi Pesic (Mediterranean), in the presence of relatively few swimming setae on IV-L-4 and 5, the absence of swimming setae on the anterior side of IV-L-5 and presence of relatively large claws on the legs (Fig. 6). H. wilesi sp. nov. differs from H. reinhardi (in parentheses data taken from Pesic 2002) in a lower number of swimming setae on II-IV-L (III-L-4 2 – 5, III-L-5 2 – 5, IV-L-4a 2 – 7, IV-L-4p 2 – 6, IV-L-5p 2 – 5), a shorter ejaculatory complex (164 vs. 180 – 210 in H. reinhardi) and rather shorter swimming setae on anterior surface on III-L-5. H. tonapii is distinguished by its relatively fewer setae on the coxal surfaces and presence of two swimming setae on posterior surface on IV-L-5 (see: Cook 1967 and remarks under H. tonapii).

Etymology: The species is named after Dr Roy Wiles (UK) in appreciation of his studies of the genus Hydrodroma.

Distribution: Australia (Northern Teritory).

Habitat: helocrene spring and stream.