Hydrobaumia purpurea, Smit, Harry, 2013

Smit, Harry, 2013, New records of water mites mainly from Vogelkop, New Guinea (Acari: Hydrachnidia), with the description of one new genus and thirteen new species, Zootaxa 3716 (2), pp. 207-235 : 207-209

Hydrobaumia purpurea n. sp.

( Figs. 1–4 )

Material examined. Female holotype, Pandanus marsh, beach Base G, Jayapura, Papua Province, New Guinea, Indonesia, 2 ° 31.035 S 140° 44.360 E, alt. 0 m asl, 29-xi-2011 (RMNH).

Diagnosis. Large median dorsal shield with a short anterior extension, large anterior dorsal plates more or less rectangular.

Description. Female: All body parts purple in colour, dorsally 626 long and 494 wide. Dorsum with nine plates: one large unpaired posterior with three pairs of glandularia, two paired anteromedial and three paired lateral plates, each with one glandularium. Large unpaired dorsal plate 429 long and 340 wide, with a short anterior extension. Suture lines of coxal plates indistinct. Fourth coxal plates with angular posteromedial corners. Genital field 136 long and 106 wide, with three pairs of elongate acetabula. Lengths of PI–PV: 30, 116, 40, 134, 24; ventral margin of PII with a heavy seta on a very short tubercle, ventral margin of PIV with two short and one long setae, and more medially a fourth seta. Lengths of I-leg-4–6: 88, 108, 96. Legs I–III claws with clawlets. Lengths of IVleg-4–6: 124, 128, 132. IV-leg-6 without claw; ventral margin of IV-leg-5 and -4 with 8 respectively 5 pinnate setae. IV-leg-5 with two relatively short swimming setae, III-leg-4 with one long swimming seta.

Male: Unknown.

Etymology. Named for its purple colour.

Remarks. This is the second species of the genus Hydrobaumia . It differs from H. malacensis Halík, 1930 , described from Malaysia (Halík 1930) in (1) the short anterior extension of the large dorsal plate (absent in H. malacensis ), (2) the two anterior glandularia of the large dorsal plate which are further away from each other (3) the paired medial anterior plates having more or less equally sized medial and lateral margins (in H. malacensis the medial margin longer than the lateral margin), (4) Cx-II not triangular, (5) the PII having a much heavier seta on the ventral margin, inserted on a very short tubercle (inserted directly on the segment in H. malacensis ), (6) the ventral margin of PIV with one long seta (absent in H. malacensis , but possibly broken off). Halík (1930) did not illustrate coxoglandularia 2, but this is probably an error.

Both species occurred in (slow flowing) streams which originate in marshy areas.

Figures

FIGURES 1 – 4. Hydrobaumia purpurea n. sp., holotype male: 1. Dorsal view; 2. Ventral view; 3. Palp; 4. IV-leg- 4 – 6. Scale bars = 50 µm.