Ototyphlonemertes (parmula) lei, 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 : 24

Ototyphlonemertes (parmula) lei sp. nov.

( Fig. 8 )

Material examined. One specimen from Dam Ngoai; ICHUM 5365 (holotype) .

Description. Body length 4.9 mm, width 0.2 mm (n =1). Epidermis whitish ( Fig. 8A ); cephalic furrow postcerebrally; tissues around brain slightly reddish; cirri present in both anterior and posterior ends of body. Foregut–in-testine junction not distinct ( Fig. 8B ). Statolith polygranular ( Fig. 8C ), 9.3 µm in diameter (n =1), consisting of about 7 granules; statocyst 15.9 µm in diameter (n =1). Proboscis diaphragm short ( Fig. 8B ); two accessory stylet pouches, lateral to central-stylet basis, each containing 4 and 5 accessory stylets, all directing forward; central stylet (as well as accessory stylets) spiral ( Fig. 8D ), 54.7 µm long; basis 43.2 µm long, 8.0 µm wide ( Fig. 8D ), with each ridge twisting about 1.5 times; basis length/width ratio 5.4; middle chamber short; posterior chamber vesicular, without specialized anterior portion ( Fig. 8B ). Intestinal diverticula deep. Posterior adhesive plate with cells containing dark contents. Gonads found in posterior half of intestinal region, alternating more or less regularly with intestinal lateral diverticula.

Distribution. So far known only from the type locality, the island of Dam Ngoai, Vietnam.

Etymology. The specific name is a noun in the genitive case, after Dr Doan Dung Le at the Ho Chi Minh City University of Food Industry, Vietnam, who kindly coordinated HK’s sampling trip to Phu Quoc.

Remarks. In the phylogenetic tree, Ototyphlonemertes ( parmula ) lei sp. nov. appeared to be sister to the rest of the O. parmula species group ( Fig. 2 ), which was mostly represented by the Fila morpho-group of Leasi et al. (2016).

Figures

Fig. 8. Ototyphlonemertes (parmula) lei sp. nov., ICHUM 5365 (holotype). A, Entire body; B, composite photomicrograph of squeezed specimen; C, statolith; D, central stylet and basis.

Fig. 2. 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.