Prostoma maculatum, Timofeev, 1911

Kajihara, Hiroshi, 2025, A taxonomic revision of the freshwater monostiliferous hoplonemertean genus Prostoma Dugès, 1828 (Nemertea: Eumonostilifera): a radical solution or an over-lumping?, Zootaxa 5646 (4), pp. 451-500 : 487

7. Prostoma maculatum

(Annex Fig. 1G )

Description. Body length up to 14 mm, width up to 0.5 mm. Head not separated from remaining body. Body thickest at posterior 1/3, ending blunt-conically. With distinct brown cephalic patch behind first pair of eyes, as in Prostoma coronatum . Clusters of shiny, white glands present behind and in front of cephalic patch. Body colour from dirty yellow to reddish, less often pinkish and brown; anterior end of body transparent. Dorsally, more-orless sharp, rather large, white spots with red greenish and bluish tints being obvious. With transmitted light, these spots are transparent, delicate, pinkish-red colour, sometimes little noticeable. Location of spots on dorsal surface variable: sometimes arranged medially in single, sparse row; or 2–3, randomly located rows along midline; or sometimes scattered along the back without order (as in the attached figure). Rarely, smaller white specks of glands are mixed with the spots.

Localities. Dirty silt, off Darse (Annex Fig. 2 , VI). Sublittoral, silt, depth 16–18 m (Annex Fig. 2 , II). Among roots of Posidonia (Annex Fig. 2 , VII, VIII, IX). Small gravel with shells, depth 40 m (Annex Fig. 2 , XIX). Stones with bryozoans, 50 m ((Annex Fig. 2 , XXIII).

Remarks. The original figure (рис. 7) shows two accessory stylet pouches, each containing two or three accessory stylets; now Tetrastemma maculatum ( Timofeev, 1911) .

Figures

FIGURE 1. Maps showing the three sampling points C1, C4, and D2 in Inoue et al. (2012) in Nanko, the southern part of Lake Biwa; white arrowheads indicate the approximate positions of the localities from where Prostoma ohmiense Chernyshev et al., 1998 was described (the holotype locality is the northern one).

FIGURE 2. Prostoma clepsinoides Dugès, 1828 from Lake Biwa, Japan. A, Entire specimen in living state, lost after photographed. B, C, Transverse sections through proboscis anterior chamber; white arrowheads pointing to proboscis nerves. D, Sagittal section through the opening of the oesophagus–rhynchodaeum complex; black arrowheads pointing to cilia on ventral wall of oesophagus; anterior to the left. E, Magnification of D, showing sparse cilia on ventral wall of oesophagus, indicated by black arrowheads. F, Magnification of D; black arrowhead pointing to longitudinal muscle fibre along rhynchodaeum.G, Sagittal section near rhynchodaeal opening; anterior to the right. B, D, E, F, ICHUM 6272; C, ICHUM 6277; G, ICHUM 6273.