Macrodasys nigrocellus Hummon 2011

Adult being described Lt 524 µm (another Lt 558); LPh 161 µm (another LPh 230) to PhJIn at U31 (another to PhJIn at U41) (Fig. 8). Body medium in length as an adult, ventrally flattened, dorsally vaulted, robust; head stepped, narrowing toward the mouth, bearing a band of circumcephalic cilia at U01–U02, pestle organs in the step at U03 and black ocelli borne just behind pestle organs at U05 (black throughout its development from juvenile to adult); trunk broader in the pharyngeal than in the fore-gut region, broadest in the mid-body regions narrowing quickly in the hind-gut region to the long caudum. Widths at pestle organs /ocelli /PhJIn /trunk /anus /caudum, and locations along the length of the body are as follows: 41 /55 /64 /86 /34 /9–7 µm at U03 /U05 /U31 /U49 /U84 /U92–U97, respectively. Glands 8 per side (5 µm diameter), distributed 3 along the pharynx and 5 along the rear half of the intestine. Adhesive tubes: TbA 7–8 per side (L 7–9 µm), in arcs that insert directly on the postoral body surface at U02–U03 and project from forward to obliquely outward; TbL 14, of similar size (L 12–18 µm), with 3 at U55, U64 and U73, and the other 11 at U80 and behind (7 along the hind-gut, and 4 behind the anal aperture); TbV 14 per side, even in size (L 12–15 µm) but uneven in spacing, with 1 along the rear pharynx, 1 just behind the PhJIn and the remainder in the intestinal region from U41 to U77, mostly concentrated in the rear, and 0 behind the anus; TbP 10–11 per side (L 12–15 µm), mostly symmetrical along the caudum, 2 at the terminus and 8–9 along the sides. Ciliation: Numerous sensory hairs (L 10–16 µm) occur on either side of the head; a band of cilia surrounds the forehead (L 10–12 µm) at U01–U02; other sensory hairs (L 12–16 µm) arise in four columns on either side of the body: lateral, lower dorsolateral, upper dorsolateral, and dorsal (in pairs), with about 32, 24, 18 and 11 per column. Ventral locomotor ciliature forms a single field that lies between the TbV series from the TbA back onto the caudal base just behind the anus, but not beneath the caudum, with small bare spots surrounding the ventral openings. Digestive tract: Mouth terminal, narrow in width (10 µm diameter), surrounded by sharp tooth-like projections; buccal cavity shallow, lightly cuticularized, expands from oral opening to its base; pharynx has sub-basal pharyngeal pores at U24; intestine is broadest in front, narrowing to the rear and bending around the base of the caudal organ; anus is ventral at U84. Reproductive tract: Hermaphroditic; testes beginning just before the PhJIn, and extending as vasa deferentia back to the rear of the frontal organ where they join ventrally; ova develop from rear to front, with several large ova seen (two at 106 × 48 and 102 × 32 µm in size) and three smaller ovules bilaterally distributed to the rear; frontal organ Y-shaped, its nozzle in close contact with the most developed ovum, with an elongate cavern with its own ventral pore lying on the left, sperm not seen internally; caudal organ of medium length, its fore half appearing glandular, its rear half having an internal canal and a spiral muscular covering, except for the rearmost glandular sac, the caudal organ does not overlap the frontal organ.

Geographical distribution: RED SEA: EGYPT: {Wadi ’Araba [video], ^Giftun Island SE (27°10'N, 33°57'E) [video], Moon Valley [3-videos], ’Uyun Musa [video]}; ISRAEL: {Snuba (Eilat) [video]} INDIAN OCEAN: MALDIVES: {Addu-Atoll}