Maracarus, Bartsch, 2016

Bartsch, I., 2016, Arhodeoporus, Camactognathus, Plegadognathus, and Winlundia (Acari: Halacaridae), re-evaluation and geographical distribution, Acarologia 56 (4), pp. 553-571 : 563-564

Maracarus n. gen.

Type species — Halacarus gracilipes Trouessart, 1889

Etymology — Derived from mare (Latin), the sea, and acarus (Latin), a mite. Gender. Masculine.

Idiosoma — Dorsal plates AD, OC and PD often with punctate areolae but major parts uniformly ornamented, often reticulated. AD and OC each with one pair, PD with two pairs of gland pores, pores generally opening to exterior via conspicuous internal canal, this being two or more times longer than wide ( Figure 3G and I ), aperture often situated apically or subapically on domes or cones. Dorsum with six pairs of idiosomatic setae. AE with pair of epimeral pores and three pairs of setae, pair of PE each with one or two dorsal and three ventral setae. Female GA with three (rarely four) pgs on either side of GO, genital sclerites with two, rarely three pairs of sgs. Male GA with numerous pgs scatteredly arranged around GO, genital sclerites generally with five pairs of sgs, rarely with three, four or six setae on either sclerite. Adults with two pairs of internal acetabula ( Figure 3D ).

Gnathosoma — Longer than wide. Rostrum generally slender, triangular. Basal pair of maxillary setae on gnathosomal base, following pair on rostrum. Palps four-segmented, laterally attached. P-2 with one dorsal seta, P-4 with three setae in basal whorl; no seta on P-3.

Legs — Genua distinctly shorter than telofemora and tibiae. Basifemora I to IV with 2, 2, 2, 1-2 setae, telofemora with 3-6, 3-6, 2-3, 2-3. Tibia I to IV with 7-8, 6-8, 5, 5 setae. Solenidion on tarsus I dorsolateral in position, on tarsus II dorsomedial. Tarsus I to IV with 3, 0-1, 0-1, 0-1 ventral setae. Tarsi I and II each with pair of pas, tarsi III and IV with singlesided pas (species with one ventral seta) or pair of pas (species without ventral seta), in the latter case on tarsus III generally a slender and a flattened seta; on tarsus IV pas the same as on tarsus III or both flattened. Tarsi end with paired claws and a distinctly smaller median claw.

Deutonymph — Genital plate with two pairs of internal acetabula and two pairs of pgs ( Figure 3H ).

Figures

FIGURE 3: A – Maracarus eclogarius (AndrØ, 1959), female: tarsus IV, lateral (medial pas obscured, medial claw omitted); B – Maracarus kunzi (Bartsch, 1987), female: tarsus II, medial. C-E: Maracarus brevocularis (Bartsch, 1973), male: C – tarsus III, ventral (dorsal setae in broken line); D – GO and perigenital setae; E – tibia and tarsus IV, ventromedial. F – Plegadognathus bonairensis (Viets, 1936), female: GO and perigenital setae. G-J: Maracarus corallicolus (Otto, 2000): G – right part of AD with gland pore, male; H – genital plate with two pairs of pgs, sgs and internal acetabula, deutonymph; I – right OC, male; J – gnathosoma with suctoria, lateral aspect, male. (ca, canal of gland pore; epg, external porus of gland; gac, genital acetabula; hy, hyaline area; le, lens; l-pas, lateral parambulacral seta; m-pas, medial parambulacral seta; pa, porose areola; p-pgs, pori from perigenital setae; pgs, perigenital setae; sgs, subgenital setae) Scale = 50 µm. A, Gulf of Suez, 30 Dec. 1928, on sponges; B, South Africa, East London, broken shells; C-E, North Atlantic, Josephine Bank, 1 July 1967, 206 m, sediment; F, Indian Ocean, Australia, Dampier, Watering Cove, 8 Aug. 2000, algal turf on pneumatophores; G-J. Southwestern Pacific, Australia, Great Barrier Reef, Lizard Island, 13 Oct. 1998.