Cernosvitoviella minor Dózsa-Farkas, 1990

Dózsa-Farkas, Klára, Csitári, Bianka & Felföldi, Tamás, 2017, A new Cernosvitoviella species (Clitellata: Enchytraeidae) and its comparison with other Cernosvitoviella species from Sphagnum mires in Hungary, Zootaxa 4254 (3), pp. 322-338 : 333-334

Cernosvitoviella minor Dózsa-Farkas, 1990 sensu lato

( Figures 1 E–F, 10)

Cernosvitoviella minor Dózsa-Farkas, 1990: 271 –272, figs. 11–14. Rota & Healy 1999: 34 –35, figs. 1 D– E. Schmelz & Collado 2010: 59.

Material investigated: (in total 41 specimens), 4 specimens from site 1, 3 and 4 (13.10.2014), 7 specimens from site 2 (21.05.2014 and 13.10.2014), 20 specimens from site 6 (31.03.2014), 3 specimens from sites 8 and 9 (31.03.2014), 5 specimens from site 10 (13.05.2011), 2 specimens from site 11 (20.06.2016).

Body 2–3.3 mm long, 140–200 µm wide at VIII and 150–280 µm at XII, segments 19–22. Chaetae sigmoid with nodulus, up to 6–7–(8) per bundle. The clitellum, when well-developed, saddle-shaped, the glandular cells in transverse rows interrupted ventrally ( Fig. 10 F). In the prostomium about 8–10 large, rounded papillae ( Fig. 10 B). Brain ( Fig. 10 A) slightly incised posteriorly, about 85–90 µm long and 1.5 times longer than wide. Two pairs primary and two pairs secondary pharyngeal glands ( Fig. 10 J). Dorsal vessel originating at XII or XIII, blood lightpink or colourless. Interestingly, the anterior bifurcation not in peristomium, as in other Cernosvitoviella species, but in segment III ( Fig. 10 C) (observed only in two cases, not studied in all specimens, so requiring further studies). Nephridia mostly unpaired in 6/7–7/8 and 8/9 or 9/10. Coelomocytes are very variable: Originally they were described by Dózsa-Farkas (1990) as spindle-shaped, with coarse refractile granules (black in transmittent light). Later Rota & Healy (1999) found that the coelomocytes are variable in shape and colour (dark and hyaline). In the case of specimens studied here, this trait was also variable. Sometimes all coelomocytes were granulated and dark, while in other specimens there were spindle-shaped or oval-dark and hyaline cells alike. Hyaline cells are usually concentrated in the forepart of the body, while the majority of dark cells are found in the posterior part ( Fig. 10 D,E). Sperm funnels cylindrical, about 30–40 µm long and 2 times longer than wide, with high collar ( Fig. 10 G). Sperm duct about 5 times longer than the length of funnels, diameter uniform (6 µm) and without or with a small dilatation at the opening. Male pores surrounded by glands. Spermatozoa 25–29 µm long, heads 12–13 µm. Spermathecae also variable but confined to V. Ampullae spherical, length of the ectal duct can varying: In some specimens, ducts are very short (11–20 µm long and the diameters of ampullae are 14–20 µm ( Figs.1 E, 10H,J)), in other specimens, the ducts are much longer (50–55 µm long) and ampullae are also larger: diameter 23–25 µm and here the sperm is arranged mostly crosswise in the lumen ( Figs.1 F, 10I). In some cases, intermediate states were also found (e.g., duct 28 µm long, ampulla 22 µm wide). In all samples were found specimens with long and short ectal ducts alike.

Figures

FIGURE 1. Spermathecae of Cernosvitoviella species. A. C. farkasi sp. n. B. C. aggtelekiensis. C. C. atrata. D. C. crassoductus. E. C. minor s. l. with small spermatheca. F. C. minor s. l. Scale bars 50 µm.

FIGURE 10. Micrographs of Cernosvitoviella minor sensu lato. A. Brain, slightly incised posteriorly. B. Prostomial papillae (arrows, ph = pharynx). C. Anterior bifurcation of dorsal vessel in III, blood light pink. D. Different type of the coelomocytes outside the body. E. Segments III – V (spermathecae marked with larger black arrows, dark coelomocytes marked with white arrows, hyaline coelomocytes marked with smaller black arrows). F. Clitellar glands dorsally. G. Sperm funnels (arrows). H. Shorter spermathaeca (arrows). I. Longer spermatheca (arrows). J. Segments III – V (very short spermathecae marked with arrows, p = primary pharyngeal glands, s = secondary pharyngeal glands). All micrographs in vivo. Scale bars 50 µm.