Hygrobatopsis (Hygrobatopsella) inflata (K. Viets, 1925 )

Smit, Harry, 2021, Water mites from West Africa (Acari: Hydrachnidia), Acarologia 61 (3), pp. 700-746 : 717-719

Hygrobatopsis (Hygrobatopsella) inflata (K. Viets, 1925)

( Figures 11 A-E, 12A-D)

New records. Ghana. 0/1/0, unnamed stream crossing road to Ankasa NP, 5°11.435′

N 2°39.429′ W, 20 m a.s.l., 27 Feb. 2011 ; 0/1/1, stream Asukuma, Kakum NP, 5°26.995′ N 1°25.071′ W, 131 m a.s.l., 12 Feb. 2013 ; 1/2/0, Kulugu River, upstream, N of Biakpa, 6°51.223′

N 0°25.141′ E, 410 m a.s.l., 20 Feb. 2013.

Description. Male: Idiosoma dorsally 332 long and 200 wide, ventrally 348 long. Dorsum with a 4-part dorsal shield, consisting of a large anterior plate, 180 long and 194 wide, with the postocularia and one pair of glandularia, a smaller posterior plate with one pair of glandularia and two small platelets flanking the posteromedial projection, each with a glandularium ( Figure 11A ). Gnathosoma narrowly fused with Cx-I. Coxae incorporated in a ventral shield, not including the genital field. All suture lines of coxae incomplete. Cxgl-4 located near suture line Cx-III/IV ( Figure 11B ). Genital field terminal, 100 wide, with three pairs of acetabula on a pair of separate genital plates; medial and posterior margin with a row of setae ( Figure 11C ). Length of P1–5: 18, 70, 72, 100, 36. P2 anteroventrally with a large projection, P4 ventrally bulging, P5 slender ( Figure 11D ). Length of I-leg-4–6: 92, 102, 74. I-leg-5 anteriorly with a few fine setae. Length of IV-leg-4–6: 120, 132, 102. Fourth leg much heavier than first three legs, claw relatively large. IV-leg-5 and IV-leg-4 medially with three pectinate setae, IV-leg-4 anteromedially with one pectinate seta ( Figure 11E ). Swimming setae absent.

Female: Idiosoma dorsally 567-583 long and 470-518 wide, ventrally 575-616 long. Dgl-1

on a large sclerite ( Figure 12A ). A small area of integument posterior to the preocularia sclerite reticulated, but this reticulation absent in the rest of the integument. Posterior dorsal and ventral glandularia on large tubercles. Gnathosoma narrowly fused with Cx-I. Cxgl-4 near suture line Cx-III/IV. Posterior to Cx-IV a large area of secondary sclerotization. Also anterior to genital field a broad sickle-shaped area of secondary sclerotization ( Figure 12B ). Genital field 160 long, genital plates compact, 74 long, with three pairs of acetabula. Excretory pore on a large terminal tubercle. Length of P1–5: 30, 104, 118, 158, 56. Anteroventral projection of P2 more slender than in male, tip with a few minute denticles. Ventral margin of P4 less bulging than in male ( Figure 12C ). Length of I-leg-4–6: 130, 142, 103. I-leg-4 anteroventrally with two blunt stout setae, I-leg-5 without downturned seta ( Figure 12D ). Length of IV-leg-4–6: 176, 191, 132. Swimming setae absent.

Remarks. K. Viets (1925) described H. inflata based on the deutonymph only. Thus far, the adults of this species were unknown. The palp of the deutonymph of H. inflata as described by Viets agrees well with the palp of the adults and deutonymph collected in Ghana, especially the bulging ventral margin of P 4 in combination with P2 with a ventral projection is characteristic.

The male of the new species is remarkably similar to the South African H. bella Cook,

2005, given the distance between the two countries. The anterior dorsal plate H of. bella is narrower and more elongated, and the posterior dorsal plate bella of is more or less as long as bars: A-B = 100 µm; C-E = 50 µm.

wide (wider than long in inflata ). The anteroventral projection of P2 is less slender compared to bella . The female is well-characterized by its large glandularia tubercles and the large sclerite with Dgl-1.

Distribution. Cameroon (K. Viets 1925), Ghana (this study).

Figures

Figure 11 Hygrobatopsis(Hygrobatopsella) inflata(K. Viets), male. A – dorsum; B – venter; C – genital field; D – palp; E – IV-leg-4–6. Scale

Figure 12 Hygrobatopsis(Hygrobatopsella) inflata(K. Viets), female. A – dorsum; B – venter; C – palp + gnathosoma; D – I-leg-4–6. Scale bars: A-B = 100 µm; C-D = 50 µm.