Fridericia gyromonodactyla, Boros, Gergely & Dózsa-Farkas, Klára, 2015

Boros, Gergely & Dózsa-Farkas, Klára, 2015, Three new Fridericia species (Oligochaeta, Enchytraeidae) from Transylvania, Romania, Zootaxa 3911 (3), pp. 357-368 : 363-365

Fridericia gyromonodactyla sp. n.

( Figs 2 F–I, 5)

Type material. Holotype: F.20, slide No. 1019. N46.14613 E24.63541, 440 m asl, close to Malancrav village, Romania. Leg.: G. Boros, 15.10.2013. Paratypes: P.97.1–6, slides No. 1010, 1011, 1016–1018, 1023, P.97.12–13, slides No. 1031–1032 8 adults, whole mounts (last few segments missing in No. 1011, 1017, 1018). N45.89052 E24.78019, 580 m asl, near the village of Cincu, Romania. Leg.: G. Boros, 15.10.2013. P.97.7-11, 5 specimens, slides No. 1020, 1026, 1030, 1035, 1049. From type locality.

Etymology. Named after the shape of the spermathecal diverticulum: gyros = coil, mono = one, dactylus = finger (Greek).

Diagnosis. The new species can be recognized by the following combination of characters: (1) medium size (6–8 mm in vivo), segments 32–39; (2) maximum of 3 chaetae per bundle; (3) clitellum saddle-shaped: hyalocytes and granulocytes arranged in transverse rows dorsally; (4) four pairs of preclitellar nephridia; (5) coelomomucocytes a/c type; (6) bursal slit T-shaped; (7) large seminal vesicle; (8) subneural glands in XIII, XIV; (9) sperm funnel cylindrical, approximately 2/3 as long as body diameter, collar much narrower than the funnel body, sperm about 100 µm long, heads 50–80 µm long (in vivo); (10) spermathecal ectal duct contractile, shorter than body diameter, one sessile gland at the orifice, ampullae with only one long, twisted diverticulum. Ampullae mostly fused entally, joining oesophagus.

Description. Holotype 7.9 mm long, 220 µm wide at VIII and 260 µm at clitellum (fixed) (8.1 mm long, 215 µm wide at VIII and 270 µm at clitellum in vivo), 38 segments. Length of paratypes 6.5–10 mm, width 180–340 µm at VIII and 210–360 µm at clitellum (in vivo), length of fixed specimens 5.8–7.9 mm, width 220–270 µm at VIII, 240–290 µm at clitellum, segments 33–39. Chaetal formula: (1),2 –2,(1): 2,3 – 2,(1). In ventral bundles 2 chaetae only in II or in II–III, three chaetae from III–IV to XI. (In one case, slide No. 1017, in all ventral bundles only 2 chaetae). Chaetae in preclitellar bundles all of same length, about 25–32 x 2.5–3 µm both ventrally and laterally. Chaetae in XII absent. Behind clitellum only two chaetae (rarely one) per bundle, close to body end somewhat larger, about 37– 42 x 4–5 µm. Head pore at 0/I. Dorsal pores from VII. Epidermal gland cells arranged in 2–3 transverse rows per segments. Clitellum in XII–1 /2XIII, saddle-shaped, hyalocytes and granulocytes arranged in transverse rows dorsally ( Fig. 5 C). Thickness of body wall about 15–20 µm, cuticle <1 µm. Brain eggshaped, on average 110 Μm long (fixed) and about 1.6–2 times longer than wide ( Fig. 5 A).

Oesophageal appendages a-type, short, unbranched. Pharyngeal glands all united dorsally, in V and VI with long ventral lobes ( Fig. 2 F). Chloragocytes from V, about 11–19 Μm long in vivo. Dorsal vessel from XIV–XV, blood colourless. Midgut pars tumida from XX–XXVI, occupying 6 segments. Four pairs of preclitellar nephridia from 6/7 to 9/10, length ratio anteseptale: postseptale 1:2, subterminal origin of efferent duct. Coelomo-mucocytes type a/c, length 21–41 Μm in vivo and 15–25 µm fixed, lenticytes 4–7 Μm long ( Fig. 2 H). Chylus cells between IX–XI, occupying 2 segments, often not visible. Seminal vesicle large in X–XII. Sperm funnels cylindrical ( Figs 2 G, 5D,E) about 130–240 long and about 2 times as long as wide (in vivo). The funnel length in fixed specimens 95–130 µm. Collar much narrower than the funnel and high, on average 39.3±5.6 µm and 17±6.3 µm respectively, in vivo. Spermatozoa long, but the length in seminal vesicle not measurable, heads about 65 µm long (in vivo). Diameter of sperm ducts 6–8 µm in vivo and 5–6 µm fixed. Male copulatory organs ( Fig. 5 F) on average 79.6±8.7 µm long, 55±7.6 µm wide and 40.6±9.3 Μm high (fixed), bursal slits T-shaped ( Fig.5 C). Subneural glands in XIII and XIV, weakly developed, often not seen, except on slides No. 1031 ( Fig. 5 G) and 1032, where they are well visible, larger in XIII. Spermathecae ( Figs 2 I, 5H–I): one sessile ectal gland ( Fig. 5 J) covers the orifice of spermathecal duct, diameter about 26–40 µm in vivo and fixed. Ectal ducts about 100–199 µm long and 22–30 µm wide, in some cases more contractile than usual in the genus ( Fig. 5 I), the canal 5–9 µm wide, tapering at the ectal orifice ( Fig. 5 J); entally canal diameter slightly widening near lumen of ampulla, to 8–10 µm. Ampullae 34–42 µm wide (in vivo) with one long (110–200 µm by 20–32 µm, fixed) finger like diverticulum filled with sperm ( Fig. 2 I, 5I, K), twisted and rounded at the end. The proximal parts (about 40–80 µm long, fixed) of both ampullae fused at the entrance into oesophagus ( Fig. 5 H), sometimes apparently separate and attached adjacently and separately to oesophagus. One or two mature eggs at a time.

Distribution and habitat. Romania: Transylvanian Plateau, close to Cincu and Malancrav villages. Pastures, meadows.

Differential diagnosis. Previously, only five species were described in which the spermathecae have only one diverticulum ( Schmelz & Collado 2010). Among them F. monopera Cognetti, 1903 is most similar to the new species in regard to the body size and the long thumb-shaped diverticulum, but it is not twisted and it narrows at the end [“unico diverticolo allungato a mo’di ditto di gunto, at tenuato verso l’apice, a fluttante liberamente nella cavitá celomica” ( Cognetti 1903)]. F. anomala Kosel, 1975 has small diverticula and only two chaetae per bundle. F. deformis Möller, 1971 differs from the new species by having a very large, floppy spermathecal ectal gland and five pairs of preclitellar nephridia. In F. singula the shape of diverticula is spherical and the clitellum is girdle-shaped, not saddle shaped as in F. gyromonodactyla sp. n. Furthermore, F. singula and F. d ef or m is have a maximum of 4 chaetae per bundle. Finally, in F. asymmetricoides Kasprzak, 1972 the seminal vesicle is absent or small.

Figures

FIGURE 2. Fridericia transylvanica sp. n. (A – E): A. Nephridium, B. C oelomocytes. C. Sperm funnel. D. Spermatheca. E. Oesophageal appendage. Fridericia gyromonodactyla sp. n. (F – I): F. Pharyngeal gland. G. S perm funnel. H. Coelomocytes. I. Spermathecae. Fridericia longeaurita sp. n. (J – N): J. Spermathecae. K. Single spermatheca (fusion with the other not observed). L. Sperm funnel, M. Coelomocytes, N. Oesophageal appendage.

FIGURE 5. Micrographs of Fridericia gyromonodactyla sp. n. A. Brain (stained worm on slide). B. Pharyngeal glands (marked with arrows, stained worm on slide), C. Clitellar glands lateral (saddle-shaped clitellum), the male apparatus marked with arrow, in vivo. D. Sperm funnel in vivo. E. Sperm funnel in another specimen in vivo, F. Male apparatus (marked with arrows, stained worms on slide). G. Subneural glands in XIII and XIV (marked with arrows, fixed and stained worms on slide). H. Spermathecae in vivo (fusion of proximal parts marked with arrow). I. Spermatheca (spermathecal duct contracted, the coiled diverticula marked with arrow, in vivo). J. Distal part of spermathecal duct with ectal gland and tapering canal at the orifice. K. Spermathecal diverticula with sperm inside (marked with arrows, fixed and stained). All scale bars except in 5 J, K = 50 Μm.