Orostylis distortus, GOBERT, STEFAN, ARMONIES, WERNER, DIEZ, YANDER L., JOUK, PHILIPPE, MONNENS, MARLIES, REVIS, NATHALIE, REYGEL, PATRICK, SMITH, JULIAN III, STEENKISTE, NIELS VAN & ARTOIS, TOM, 2022

GOBERT, STEFAN, ARMONIES, WERNER, DIEZ, YANDER L., JOUK, PHILIPPE, MONNENS, MARLIES, REVIS, NATHALIE, REYGEL, PATRICK, SMITH, JULIAN III, STEENKISTE, NIELS VAN & ARTOIS, TOM, 2022, Orostylis gen. nov., a new genus of Dalytyphloplanida with seven new species (Platyhelminthes: Rhabdocoela), Zootaxa 5115 (1), pp. 29-46 : 34-35

publication ID	https://doi.org/ 10.11646/zootaxa.5115.1.2
publication LSID	lsid:zoobank.org:pub:E78C0947-2E8A-4663-A428-9303E84D6924
DOI	https://doi.org/10.5281/zenodo.6346931
persistent identifier	https://treatment.plazi.org/id/9AA1FEE9-8173-4D70-85B8-51CFE5A34BDF
taxon LSID	lsid:zoobank.org:act:9AA1FEE9-8173-4D70-85B8-51CFE5A34BDF
treatment provided by	Plazi
scientific name	Orostylis distortus
status	sp. nov.

Treatment

Orostylis distortus sp. nov. Armonies, Gobert & Artois

( Figs. 3G View FIGURE 3 , 4C View FIGURE 4 )

Orostylis distortus n. n. in Armonies (2017)

Localities. Sylt , Germany (55°04’44”N; 5°17’31”E) Sublittoral, 8.2 m deep, clean fine sand (Apr. 28, 2015): Type locality GoogleMaps .

Material. Observations on live specimens, one of which whole mounted and designated holotype ( FMNH KV.693) .

Etymology. The specific name refers to the stylet morphology (Lat. “distortus” = distorted).

Description. General morphology as described for the genus, with the stylet located anteriorly, lateral to the pharynx. The body is unpigmented, 0.8 mm (resting) to 1.2 mm long (swimming). The anterior and posterior body ends are more or less rounded. The mouth opens terminally or subterminally and is surrounded by few tactile hairs. Two pigmented eye spots ( Fig. 4C View FIGURE 4 : e) are situated anterior to the pharynx. The pharynx ( Fig. 4C View FIGURE 4 : ph) is cylindrical, with six 30-µm-long tentacles ( Fig. 4C View FIGURE 4 : pht). The proximal 1/3 of the tentacles’ length is anchored in the pharynx, which seems to have no circular muscles in this area and therefore differs in appearance from the distal part of the pharynx. The pharynx is only 1/8 of the body length and relatively small compared to the pharynx in other species of the genus.

The paired testes are located laterally between the pharynx and the midbody. The copulatory organ lies beside the pharynx or directly behind it in stretched specimens. Its musculature is hardly visible in live specimens. A single, elongated seminal vesicle ( Fig. 4C View FIGURE 4 : sv) and prostatic vesicle ( Fig. 4C View FIGURE 4 : pv) enter the stylet proximally. The stylet ( Figs. 3G View FIGURE 3 ; 4C View FIGURE 4 : st) is S-shaped, 42 µm long and consists of a proximal oval funnel, which rapidly narrows to a coiled, slender, 2–3-µm-wide tube ending in a pointed tip. At its proximal end, a longitudinal slit was observed.

A singly ovary is present in the midbody, with the largest egg cells occurring anteriorly. The paired vitellaria stretch from the midbody to the rear body end.