Piona, Koch, 1842

Smit, H., 2011, New Species Of Water Mites From New Guinea (Acari: Hydrachnidia, Halacaridae), Acarologia 51 (3), pp. 321-345 : 339-340

Piona piersigi (Daday, 1900)

( Figures 13–14 )

Material examined — 9/26/9, brown forest pool, along road Yoka – outlet Lake Sentani , Papua province, 2°40.737’ S; 140°36.230’ E, alt. 104 m a.s.l., 29-iii-2010 ; 6/2/2, Pandanus marsh Base G beach, Jayapura, 2°31.445’ S; 140°44.503’ E, 30-iii-2010.

Description — Male: Idiosoma 830 long and 616 wide, chitinized parts reddish to purple. Anterior coxal plates with a short apodeme. Third + fourth coxal plates medially close but not touching ( Figure 13a ). Gonopore 52 long, on a platelet with two pairs of acetabula; anterior margin of this platelet distinct, posterior margin indistinct. The remaining 12 pairs of acetabula are lying free in the idiosoma ( Figure 13b ). Excretory pore touching gonopore platelet, but in other specimens distanced from this platelet. Lengths of PI-PV: 32, 130, 78, 130, 48. Ventral margin of PII convex, with two heavy, relatively short setae medially and three heavy setae near or on dorsal margin; PIII medially with one relatively short, heavy seta and two setae near or on dorsal margin; PIV ventrally with three setal tubercles, lying close to each other ( Figure 13c ). Lengths of I-leg- 4-6: 164, 190, 186 (the latter till tip of segment). Dorsal seta of III-leg-6 extended ( Figure 13d ). Lengths of IV-leg-4-6: 86, 150, 190. Legs with less swimming setae compared to female, e.g. IV-leg-5 with four and IV-leg-4 with three swimming setae ( Figure 13e ). All legs with numerous heavy setae.

Female: Idiosoma 778 – 1266 long and 624 – 1065 wide; colour of chitinized parts as in male. Medial distance of third + fourth coxal plates large ( Figure 14a ). Genital plates more or less curved, with anteriorly two acetabula on a platelet, posteriorly 7 – 12 acetabula on a platelet and in between 1 – 2 acetabula lying free in the idiosoma ( Figure 14b ). Pregenital sclerite 92 wide, postgenital sclerite 84 wide. Lengths of PI-PV: 36, 136, 66, 134, 42. Ventral margin of PII convex, with two short, heavy setae medially and one on dorsal margin (broken off in illustrated palp). PIII with three heavy setae (one seta lost in illustrated palp). Ventral margin of PIV with two small, setal tubercles, well distanced from each other; third ventral seta on a small tubercle, which is lying more distanced from ventral margin ( Figure 14c ). Lengths of I-leg-4-6: 170, 203, 211 (the latter till tip of segment). Lengths of IV-leg-4-6: 211, 243, 194. All legs with numerous swimming setae and numerous heavy setae.

Remarks — The illustrations of Daday (1901) are very sketchy, and therefore new illustrations are provided. Daday (1901) reported the species from German New Guinea, nowadays Papua New Guinea.

Figures

FIGURE 13: Piona piersigi (Daday), male: a – ventral view; b – genital field; c – palp; d – III-leg-6; e – IV-leg-5-6. Scale bar = 50 µm.

FIGURE 14: Piona piersigi (Daday), female: a – ventral view; b – genital field; c – palp. Scale bar = 50 µm.