Comprehensive DescriptionRead full entry
DescriptionTrunk of adult specimen being described Lt 440 µm (others Lt 413–480); Lt tail 1100 µm (others Lt 588–1620); LPh 174 µm (others LPh 161–173) to PhJIn at U40 (others PhJIn at U34–U40) (Fig. 12 A, B). Trunk medium in length as an adult, ventrally flattened, dorsally vaulted; head bluntly ovate, with a narrow band of circumcephalic cilia and broad pestle organs at U05; neck constriction slight; trunk broadest along the mid-gut, narrowing gradually in the hind-gut region to the elongate tail. Widths at pestle organs /pharyngeal pores /PhJIn /front, rear of caudal organ, and locations along the length of the body are as follows: 46 /48 /50 /54, 30 µm at U03 /U33 /U46 /U72, 97, respectively. Glands 15–16 per side (4–7 µm), larger in front than behind. Adhesive tubes: TbA 7 per side (L 12 µm), 3 in transverse rows at U07, which project obliquely forward, curving laterally to form longitudinal columns of 4 at U08–U17, the latter projecting obliquely outward, all inserting directly on the postoral body surface; TbL 4 per side, similar in size (L 15 µm), all in the intestinal region at U54, U62, U75 and U88; TbVL 4 per side, similar in size (L 14–16 µm), 2 along the fore and 0 along the rear pharynx, and 2 in the rear intestinal region as the caudal base narrows; TbD 5 per side (also L 15–20 µm), 1 along the fore and 0 along the rear pharynx pores, and 4 in the intestinal region; TbV absent; TbP 10 or more per side (L 10–12 µm) asymmetrically about the tail, depending on its length. Ciliation: Numerous sensory hairs (L 10–16 µm) occur around the head; a band of cilia surrounds the forehead (L 28–30 µm) at U05; other sensory hairs (L 25 µm) arise in two columns on either side of the body: lateral and dorsolateral, with about 30 per column. Ventral locomotor ciliature forms paired lateral bands that run from the TbA back to the rear of the caudal organ, with more sparsely placed cilia filling the space between from TbA to U49. Digestive tract: Mouth terminal, narrow (6 µm diameter); buccal cavity expands from oral opening to base and is lightly cuticularized; pharynx has sub-basal pharyngeal pores at U33; intestine is broadest in front, narrowing to the rear, but lacks an anus. Reproductive tract: Probably hermaphroditic, though testis was not seen; ova develop from rear to front, with two bilateral ova (74 × 24 and 55 × 19 µm in size) in the mid-gut region of recently mature specimens, and a much larger ovum (138 × 98 µm in size) appears in fully mature specimens (video #1904); frontal organ not seen; caudal organ, appearing enclosed as an oval capsule, has a hyaline bulblet in the rear, with an internal canal, that circles around to include a darkish mass on the left and a curved stylet on the right (Fig. 12 C), which is thin and curved in the rear, widening and straightening toward the front, where it has an asymmetrical bulb that has a symmetrical opening at the end.