Kawamuracarus biscutatus, Smit, 2014

Smit, H., 2014, The First Hyporheic Water Mites From The Afrotropical Region (Acari: Hydrachnidia), With New Species Of The Genera Kawamuracarus Uchida And Bharatohydracarus Cook, Acarologia 54 (1), pp. 39-45 : 40

Kawamuracarus biscutatus n. sp.

( Figures. 1 A-C, 2A-C)

Material examined — Holotype female, Agumatsa River at first bridge crossing track, Agumatsa Wildlife Sanctuary, Ghana, 7º 06.830’ N; 0º 35.760’ E, alt. 253 m asl, 22-ii-2013 ( RMNH).

Diagnosis — Dorsum with two large plates; PIV with extremely long setal tubercles located far proximally and a very long medial seta inserting at the same level.

Description — Female: Idiosoma pale yellow, 599 long and 365 wide. Eyes absent. Dorsum with two large plates, a smaller anterior plate, 130 long and 203 wide and a larger posterior plate, 332 long and 243 wide. Anterior plate with two pairs of glandularia and the paired postocularia, posterior plate with two pairs of glandularia. Anterior coxal plates not fused medially. Fourth coxal plates triangular, posterior to fourth coxal plates an extensive area of secondary sclerotization. Genital field 174 long and 138 wide, with three pairs of acetabula, acetabular plates indented between anterior pair and central pairs of acetabula; anterior acetabula elongated, posterior acetabula somewhat triangular. Pregenital sclerite 58 wide. Posterior to genital field a small platelet. Length of PI-PV: 30, 62, 70, 118, 56. Ventral margin of PII with a seta, inserted directly on segment surface. PIV with two very long setal tubercles (although no setae could be seen), anterior setal tubercle longer than posterior setal tubercle; at base of these long tubercles, which are inserted far proximally, two short tubercles. Medial margin of PIV with a very long seta, located proximally, on the level of the tubercles and extending beyond anterior margin of segment. PV long and slender. Lengths of I-leg-5-6: 94, 102, 110. Length of IV-leg-4-6: 138, 182, 152. IV-leg-6 with small claws and a terminal seta, 36 long.

Etymology — Named for the two dorsal plates.

Remarks — The presence of two dorsal plates is unique within the genus, and will separate it from all other known species. All species known from Mexico, North-America and Japan have three large plates, two anterior and one unpaired posterior plate. In species from the Oriental region (including Oman) and the W. Palaearctic, the dorsal platelets are either much smaller or absent. Moreover, no other species has a PIV with similarly long tubercles and medial setae. Also in K. polyporus Cook, 1967 from India, most similar in this character state, these extensions and setae are not as long as in the new species. This species differs from K. biscutatus furthermore in a higher number of acetabula (8-14 pairs, Cook 1967).

Figures

FIGURE 1: Kawamuracarus biscutatus n. sp., holotype female: A – Dorsal view; B – Ventral view; C – Palp. Scale bars = 50 µm.