Tetranchyroderma corallium Hummon 2011

Adult Lt 280–332 µm; LPh 85–80 µm to PhJIn at U30–U29 (Fig. 13). Body short, robust, ventrally flattened, dorsally vaulted; head end truncated, without pestle organs, tentacles or lobes; lacking any neck, broadening through out the pharyngeal region, then even more along the fore-gut, before narrowing gently to the caudal base; cirrata 6 per side of nearly similar lengths (L 16–22 µm), dorsolateral at U10, U30, U45, U62, U79 and U96, the last one homologous with the cirratum that is so often associated with the pedicles; caudal pedicles medium (L 17µm), borne on fleshy lobes, with a broad concave margin separating the two lobes, incising medially to U94. Widths at mouth /rear pharynx /mid-gut /caudal base, and locations along the length of the body are as follows: 26 /49 /53 /32 µm at U01 /U29 /U48 /U96, respectively. Glands 6 per side (3–8 µm diameter) scattered in lateral columns at U15–U79. Cuticular armature: Epidermis armored with pentancres (L 5, W 2 µm), much taller than wide, the central tine 20% longer (L 6 µm) than the other four (Fig. 13 B); ancres of similar size over much of the body, but are smaller fore and aft; ancres cover dorsal and lateral surfaces in some 55–60 rows of 15–17 ancres each, extending onto the rear of the oral hood and onto the caudal lobes. Adhesive tubes: TbA 7 per side (L 4–6 µm), forming three rows of 2 (medial), 3 (lateral) and 2 (smaller, behind the lateral) tubes, all projecting obliquely forward and all inserting directly on the postoral body surface at U05–U07; TbVL 18 per side (L 4–10 µm), 1 at U08, inserting just behind the TbA, a group of 11 at U25–U71, 1 at U80, and a group of 5 at U86–U95, the first tube being shorter than the others; TbV 3 per side (L 7–9 µm), 1 at U65 and a row of 2 at U72; TbDL 4 per side (L 7–10 µm) at U13, U47, U64 and U80; TbL/Dper seare absent; TbP 3 per side on the caudal pedicles, forming the fused ‘two fingers and a thumb’ typical of the family, (L terminal tubes 4–5 µm, L tube on the inner margin 6 µm), supplemented by the last of the dorsal cirrata, with 5 additional tubes (L 8–9 µm) in the space between the peduncles. Ciliation: Short sensory cilia occur around the ventral oral opening (L 4 µm), with a number on the oral hood (L 7–8 µm), 1 longer per side (L 36 µm) being quite active, as well as numerous cilia laterally (L 5–12 µm); other cilia (L 12–20 µm) occur regularly along the lateral, dorsolateral and dorsal body surfaces, numbering 12–13 each. Ventral locomotor ciliature forms a single field of transverse rows from TbA to anus, lying between the TbVL columns; individual cilia are 6–8 µm in length. Digestive tract: Mouth subterminal, as broad as the fore end of the body (23 µm width); oral hood extends from U00 to U04; buccal cavity is lightly cuticularized; pharynx has inconspicuous basal pharyngeal pores; intestine narrows gradually front to rear; anus is ventral at U91. Reproductive tract: Hermaphroditic, testis on right side as seen from above (left side as seen from below); vas deferens appears to open into the caudal organ in front of the anus; the developing ovum (up to 49 × 22 µm) occurs above the hind-gut; caudal organ ovoid (14 µm outer diameter) is thick-walled, except where the vas deferens enters; frontal organ spherical and hyaline, bearing active sperm, partly embedded in the rear of the ovum.

Geographical distribution: RED SEA: EGYPT {Sharm el-Arab Inside, Wadi ’Araba [video], Marsa Bareika N, ^Middle Garden (27°54'N, 34°21'E) [2-videos]}.