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DescriptionThe description is mainly based on the adult specimen, 358 µm in total length, shown in Figure 3. Body somewhat slender, little swollen in the posterior pharyngeal region and at the base of the 43 µm-long caudal pedicles. Pharynx 81 µm in length, measured from the ventral border of the oral opening to the pharyngeo-intestinal junction; pharyngeal pores near the base, at U29.5; pharyngeo-intestinal junction at U32; widths of neck\PhIJ\trunk\caudal base 30\29.5\40\31 µm at U15\U31\U51\U82, respectively. Head with well developed, fleshy preoral palps, incurving ventromedially; the dorsal border projecting just beyond the ventral. Sensory hairs and papillae occur on dorsal and ventral borders of the preoral palps; hairs are scattered on the dorsal, lateral and ventral surface of the palps; dorsally there are five papillae, nearly same in length (8–10 µm), symmetrically arranged along the inner border of the palps in a 2 + 1 + 2 pattern; ventrally, there are eight papillae, 5–8 µm in length, symmetrically arranged more centrally about the inner border of the palps in a 4 + 4 pattern; all papillae bearing one or two, short sensory hairs at their tip; other hairs form lateral columns that are evenly spaced from U12.5 to U85; individual hairs are 12–15 µm in length. Glands barely visible, variable in shape (oval to oblong) and size (4-8 µm in diameter), asymmetrically scattered along most of the length of the body. Cuticular armature. Small sized pentancres with delicate, curved grasping tines, as tall as wide (3 × 3 µm – 5 × 5 µm) on whole dorsal and ventrolateral surface, except for a bare, roughly T-shaped area posterior to the palps; posteriorly most ancres extend onto the caudum. Adhesive tubes. TbA, 2 per side (7-8 µm in length) in a row at U7.8; TbDL, 1 per side (15-18 µm in length), robust, inserting on the lateral margin of the posterior trunk region at U83.5; TbVL, 11 per side, 2 smaller ones (9-11 µm in length) in the anterior pharyngeal region, roughly at U16, 7 of slightly variable size and length (11-16 µm in length), irregularly spaced in the intestinal region from U33.5 to U71.5, the remainder 2, of unequal length (10 and 14 µm), originate from a common base at U76.2; TbP, 4 per side, 2 + 1 (5-6 µm in length) at the end of each foot of the furcated caudum and the other one (10 µm in length) flanking each foot medially. Ventral locomotor cilia. A continuous field of transverse rows covering sparsely the entire surface from U12 to U35; the field splits in the anterior intestinal region to form paired lateral tufts that extend onto the ano-genital area at U84. Reproductive system: testis on the right body side, caudal organ inverted pyriform (11 × 22 µm), at U78; frontal organ bladder-like (9 µm in diameter), at U74.5; maturing eggs mid-dorsally above the posterior half of the intestine. Measurement and variability. Body length of 15 living specimens ranged from 340-425 µm (mean = 388 µm, SD = 25.4 µm) all of them were mature (i.e., showed at least the testicles filled with sperm). Strange enough all of the SEM prepared specimens resulted of smaller size (i.e., less then 300 µm) even though only specimens appearing larger under the dissecting microscope were selected for this scope; these measurements are well below the 5.5% length reduction allowed for fixed specimens (cf. Clausen 2004a). The adhesive tubes of the TbVL series showed some variability in number, depending on individuals, ranging 11-15; however, the one borne on a common base numbered invariably two per side. Three specimens, 415-425 µm in total body length, collected in September 2003 from praia do Tenório and praia Grande showed 3-4 tubes of “cirrata” type along each dorsolateral side of the trunk region; cirrata tubes where never observed in specimens collected during the 2002 campaign. The meaning of these differences is unknown.