Ototyphlonemertes (macintoshi) ani Chernyshev, 2007, 1863

Kajihara, Hiroshi, Tamura, Kotaro & Tomioka, Shinri, 2018, Histology-free Descriptions for Seven Species of Interstitial Ribbon Worms in the Genus Ototyphlonemertes (Nemertea: Monostilifera) from Vietnam, Species Diversity 23 (1), pp. 13-37 : 22-24

Ototyphlonemertes (macintoshi) ani Chernyshev, 2007

( Fig. 7 )

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 ), 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 ). Statoliths polygranular ( Fig. 7 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 ). Proboscis anterior chamber with tactile papillae ( Fig. 7L ); diaphragm long ( Fig. 7K, L ); 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 ), 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 ), with prominent diagonal muscle fibers ( Fig. 7L ); 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 ). The GenBank COI sequences KU230129 and KU230131 (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.

Figures

Fig. 7. Ototyphlonemertes (macintoshi) ani Chernyshev, 2007. A, Entire body; B, composite photomicrograph of squeezed specimen; C–J, statoliths (arrowhead on C indicates additional statolith); K, proboscis diaphragm and middle chamber; L, everted proboscis (arrowheads indicating rhabdoid-like papillae); M, central stylet and basis. A, E, M, ICHUM 5359; B, D, ICHUM 5358; C, K, ICHUM 5357; F, L, ICHUM 5360; G, ICHUM 5361; H, ICHUM 5362; I, ICHUM 5363; J, ICHUM 5364.

Fig. 3. Part of the phylogenetic tree resulting from the maximum-likelihood analysis of COI (ln L=−15264.650301), along with results of three species-delimitation analyses, ABGD, PTP, and TCS, as indicated by vertical bars. Numbers near nodes indicate maximum-likelihood bootstrap support value.