Ototyphlonemertes ( macintoshi ) ani Chernyshev, 2007, 1863

Ototyphlonemertes ( macintoshi) ani Chernyshev, 2007

( Fig. 7 View Fig )

Ototyphlonemertes ( Norenburgia) ani Chernyshev, 2007: 196–199 , figs 1, 2.

Ototyphlonemertes lactea (not of Corrêa 1954): Leasi et al. 2016: 1393, fig. 4a, network L3 (139, 160, 180).

Material examined. Eight specimens, all from Dam Ngoai; ICHUM 5357–5364.

Description. Body length 4.3–11.0 mm, width 0.3– 0.4 mm ( n =8). Epidermis whitish ( Fig. 7A View Fig ), containing red pigment cells sporadically scattered among other epidermal cells; cephalic furrow post-cerebrally; tissues around brain reddish; cirri not found on cephalic region ( n =5), 5–7 cirri found near hind end of body ( n =3). Foregut-intestine junction distinct ( Fig. 7A, B View Fig ). Statoliths polygranular ( Fig. 7 View Fig C–J), 10.9–14.7 µm in diameter ( n =8), consisting of about 22 granules; statocyst 20.9–30.4 µm in diameter ( n =8); additional statolith found in one specimen on single side ( Fig. 7C View Fig ). Proboscis anterior chamber with tactile papillae ( Fig. 7L View Fig ); diaphragm long ( Fig. 7K, L View Fig ); two accessory-stylet pouches, lateral to central-stylet basis; 2–6 accessory stylets per pouch ( n =8 individuals ×2 pouches), with mode being 5 (three individuals having 5 accessory stylets in each pouch; one individual with 4 and 5 accessory stylets, another with 5 and 6 accessory stylets); of 69 accessory stylets in 8 specimens, 2 in one specimen directed forward, other 67 directing backward; central stylet (as well as accessory stylets) spiral ( Fig. 7M View Fig ), 28.5–46.2 µm long; basis 27.7–33.3 µm long, 4.1–6.5 µm wide ( n =8), with each ridge twisting almost only once; basis length/width ratio 4.58–6.5; middle chamber antero-posteriorly elongated rectangle ( Fig. 7K View Fig ), with prominent diagonal muscle fibers ( Fig. 7L View Fig ); posterior chamber vesicular, without specialized anterior portion. Intestinal diverticula shallow and sack-like. Posterior adhesive plate with pale brown pigments.

Distribution. Tche Bay ( 12°35′N, 109°20′E), Hong- Long Island, Van Phong Bay, Vietnam ( Chernyshev 2007); Dam Ngoai, Vietnam (present study); Gesashi, Okinawa, Japan ( Leasi et al. 2016); Shirahama, Japan ( Leasi et al. 2016).

Remarks. In the molecular phylogenetic tree, O. ( macintoshi ) ani was nested within a clade comprised of other OTUs representing the O. macintoshi species group ( Fig. 3 View Fig ). The GenBank COI sequences KU230129 View Materials and KU230131 View Materials (from Shirahama, Japan: Leasi et al. 2016), as well aKU230130 (from Gesashi, Okinawa, Japan: Leasi et al. 2016), all identified as Ototyphlonemertes lactea , turned out to represent O. ( macintoshi ) ani . It was the most abundant species in this study.