Fridericia lacii, Dózsa-Farkas, 2009

Dózsa-Farkas, Klára, 2009, Review of the Fridericia species (Oligochaeta: Enchytraeidae) possessing two spermathecal diverticula and description of a new species, Journal of Natural History 43 (17 - 18), pp. 1043-1065 : 1044-1062

Fridericia lacii sp. nov.

( Figures 1–3 )

Type material

Holotype: F.15 (slide no. 96), fixed in ethanol with formaldehyde and stained with borax–carmine, whole-mounted on slide; Mecsek Mountains 46 ° 169130 N, 18 ° 209130 E, 185 m altitude, meadow, coll. K. Dózsa-Farkas and J. Farkas, 30 October 2007.

Paratypes: P.85.1 (slide nos 76–79), four specimens, fixed in ethanol and stained with mixed paracarmine and bromophenol blue, whole-mounted on four slides; from the type locality, coll . K. Dózsa-Farkas and G. Boros, 16 November 2006 . P.85.2 (slide nos 86–88, 90) 10 specimens on three slides from the type locality, fixed in ethanol, one specimen stained with borax–carmine (no. 86) and the others stained with mixed paracarmine and bromophenol blue, coll . K. Dózsa-Farkas and J. Farkas, 30 October 2007 . P.85.3 (slide nos 91, 92, 98) three specimens on three slides, from the type locality, fixed in ethanol plus formaldehyde, stained with mixed paracarmine and bromophenol blue, coll . K. Dózsa-Farkas and J. Farkas, 30 October 2007 . P.85.4. (slide nos 93–95) three specimens on three slides, from the type locality, fixed in ethanol plus formaldehyde, stained with borax–carmine, coll . K. Dózsa-Farkas and J. Farkas, 30 October 2007 . P.85.5 (slide no. 80), three specimens on one slide from along the Szamos River , Olcsvai kapu, 48 ° 059120 N, 22 ° 209290 E 144 m altitude, meadow, fixed in ethanol, stained with mixed paracarmine and bromophenol blue, coll . K. Dózsa-Farkas and J. Farkas, 30 May 2002 .

Other examined material: two adult specimens from the Gerecse Mountains, Héreg 47 ° 389140 N, 18 ° 339580 E, 222 m altitude, oak forest (coll. J. Kontschán) were investigated and drawn alive. Unfortunately this material was lost .

Etymology

Named in honour of my husband (László Abaffy, whose nickname is Laci) for his many decades of long loyal help in my scientific work.

Description

Small worm, holotype is 6.3 mm long and 210 Mm wide in segment VIII and 250 Mm at the clitellum (fixed), segments 34. Body length of paratypes 4–7 mm, width 200–250 Mm in VIII and 250–290 Mm at the clitellum (in vivo), length of fixed specimens 2.7–6.4 mm and the diameter 180–260 Mm in VIII, 220–290 Mm at the clitellum, segments 30–36. Chaetae a maximum of four per bundle, formula ( Nielsen and Christensen 1959): (1,0,2),3,4–(1,2),3,4:4,3,2–4,3,2. Outer chaetae longer than inner, e.g. the 40–45 Mm and 20–27 Mm, respectively in a preclitellar bundle; only two postclitellar chaetae from XXVII–XXIX. In the caudal region the chaetae are 55– 57 Mm long; absent in XII. Large, pale epidermal gland cells on anterior segments, in a single row immediately posterior to the level of chaetae, or one to three rows per segment. Body wall 15–16 Mm thick, cuticle thin (1 Mm). Head pore at 0/I. Dorsal pores beginning from VII. On the prostomium some papillae (perhaps sensory) were discernable ( Figure 2H ). Brain ( Figure 2A ) 1.5–1.6 times longer than wide (90– 105 Mm long). Oesophageal appendages (peptonephridia) ( Figure 1A ) unbranched, short with wide lumen, type a (after Nielsen and Christensen 1959). Pharyngeal glands (septal glands) all in pairs with ventral lobes ( Figure 2D ), in IV are small, in VI distinctly larger, often with posterior projection ( Figure 2E ). First pair with wide dorsal connection, second pair with narrow dorsal connection or free, third pair dorsally separate. Only three pairs of preclitellar nephridia from VII/VIII to IX/X, the postseptale is 1.5 times longer than the anteseptale; efferent duct arising medially or terminally ( Figure 1D ). Coelomocytes ( Figure 1B ): mucocytes type a (according to Möller 1971), cell outline slightly wavy, with clearly visible nuclei, no refractile vesicles, length 20–32 Mm, lenticytes 4–7 Mm long, numerous. Chylus cells in X–XII occupying two segments ( Figure 2C ). Dorsal blood vessel from XIV–XV (XVI); blood colourless The blood vessels in the anterior segments ( Figure 2B ) agree with the delineation in Fridericia perrieri by Vejdovský (1879; pl. 8 fig. 8). Ventrally inflated gut epithelium in XVIII–XXIV extending over two or three consecutive segments. The gut cells stain deeper in K XV–XX over three to four and a half segments ( Figure 2F,G ). Chloragocytes not much elevated, about 7–10 Mm long with fawn-coloured sparse granula. Clitellum well developed, XII– K XIII girdle shaped, hyalocytes and granulocytes arrangement in 16–17 rows, hyalocytes (diameter 12– 17 Mm) isolated from one another, granulocytes (4–5 × 14–15 Mm) in fixed specimens situated in interspaces of hyalocytes ( Figure 3A ); only granulocytes between the bursal slits ( Figure 3B ). The male openings are in the first third of the clitellum: four to six transversal rows of hyaline cells in front of the male opening and 10–12 rows after it ( Figure 3B ). Seminal vesicle small or absent. Sperm funnel mostly cylindrical, tapering distally, 90–150 Mm long and 45–65 Mm wide (fix), collar narrower than the funnel body ( Figures 1C , 3C,D ). Spermatozoa 70–95 Mm long, heads 40–50 Mm (fix). Vas deferens 5–5.7 Mm wide. Male copulatory organs ( Figure 3B ) are 60–70 Mm long, 40–50 Mm wide and 40–42 Mm high, modiolus distinct, the laterally bent bursal slits are longitudinal ( Table 3). No subneural glands. Spermatheca ( Figures 1E , 3E,F ): one floppy ectal gland (25–37 Mm long, 15–20 Mm wide fix). The ectal duct of spermatheca about 150–180 Mm long and 12–12.5 Mm wide, slightly projecting into the ampulla. The ampulla is 1.5–2 times wider than the ectal duct, its distal part set apart from the proximal part (ental duct) by an outer constriction. The distal part of the ampulla with two sessile (or with short stalks), spherical, thin-walled diverticula (diameter 18–27 Mm), empty or filled with spermatozoa, arranged in a circle, not brownish. The communication of spermathecal ectal ducts with the oesophagus is separate but dorsolaterally they are close to each other. One or two mature eggs at a time.

Distribution and habitat

Widespread in Hungary: Mecsek Mountains; along the Szamos River; Gerecse Mountains. In meadows and oak–hornbeam woods.

Diagnosis

The new species can be recognized by the following combination of characters: (1) the size of worms (4–7 mm long, 200–290 Mm wide in vivo, segment number 30–36; (2) maximum four chaetae per bundle; (3) body wall thick, cuticle thin; (4) all pairs of pharyngeal glands with ventral lobes (of which the third is the largest, often with posterior projections), the first pair with a wide, the second pair with a narrow dorsal connection (the latter may be free) and the third pair separate dorsally; (5) only three preclitellar nephridia; (6) oesophageal appendages type a; (7) coelomo-mucocytes type a, lenticytes small; (8) chylus cells in preclitellar segments; (9) clitellum girdleshaped, hyalocytes and granulocytes arranged in transverse rows, only granulocytes between the bursal slits; (10) the male opening is in the first third of the clitellum, the laterally bent bursal slit is longitudinal; (11) seminal vesicle small or absent; (12) sperm funnel cylindrical, half as long as body diameter approximately twice as long as wide, collar narrower than the funnel body; (12) subneural glands absent; (13) the ampulla of the spermatheca with two sessile (or with short stalks), spherical, thinwalled diverticula (diameter 18–27 Mm), communication with the oesophagus separate dorsolaterally, but close to each other. One 25–37 Mm long floppy ectal gland, ectal duct about as long as body diameter.

Differential diagnosis

Fridericia species with two spermathecal diverticula can be divided into several subgroups as described below. On this basis F. lacii sp. nov. belongs to the subgroup characterized by two globular, sessile diverticula mostly with spermatozoa in them, and the two spermathecae opening separately into the oesophagus ( Tables 3, 4). Unique characters of the new species are the presence of only three pairs of nephridia in the preclitellar segments from 7/8 to 9/10. On the basis of spermathecal shape the three species most similar to F. lacii sp. nov. are F. isseli , F. larix and F. globuligera , but they all appear clearly separate from the new species in the following main respects. Fridericia isseli : coelomo-mucocytes with refractile vesicles at cell periphery (type b), four preclitellar nephridia, saddle-shaped clitellum and male copulatory organ with two small globular bodies located anteriorly and posteriorly to the central glandular body. Fridericia larix : larger worm (12–15 mm), chylus cells absent in front of clitellum (XII–XIV), five pairs of preclitellar nephridia, bursal slit transverse, spermathecal ectal duct longer than body diameter. Fridericia globuligera : this species is also larger (11–15 mm long, more than 40, even up to 55 segments), maximum number of chaetae in preclitellar ventral bundles is six, chylus cells in postclitellar position (K XIII– K XVI), five pairs of preclitellar nephridia, the bursal slit is T-shaped. The spermathecal ectal duct is short. Fridericia bisetosa , F. cylindrica and F. sohleni primarily differ from the new species in maximum number of chaetae (two) in the bundles and they are also larger. In addition, F. bisetosa has type c and F. cylindrica has type b coelomocytes, in F. sohleni the chylus cells are also in a preclitellar position, but the coelomocytes are type b (with fine granulation at the periphery) and the penial slits are T-shaped. In the case of F. viridula , F. chongquinensis and F. stephensoni all three species have a maximum of five or six chaetae and larger body size, and in the first two species the chylus cells are present from XIV and XVI, respectively. The coelomo-mucocytes of F. chongquinensis are also type c and its seminal vesicle is large. Additionally, the segment number of F. stephensoni is over 70. Fridericia nix : differs from all species of this group (from the new species as well) because of its coelomocytes. They are entirely filled with refractile vesicles and are dark brown-blackish in transmitting light. Moreover this species has a large seminal vesicle and a male copulatory organ with a T-shaped bursal slit. Finally, F. discifera differs from all the above mentioned species as it has coelomo-mucocytes with peripheral granulation (type b), subneural glands in XIII–XIV (XV) and its bursal slit is T-shaped or Y-shaped.

Comparative analysis of Fridericia species with two spermathecal diverticula

Including F. brunensis Schlaghamersky´, 2007 ( Schlaghamerský 2007) the number of valid Fridericia species with two diverticula per spermatheca is 50. This group was divided into three subgroups on the basis of the maximum number of chaetae per bundle by Schmelz in his Fridericia identification key ( Schmelz 2003). As I consider the spermathecal characteristics of outmost importance for identification ( Dózsa-Farkas 2008), especially in this genus, I have attempted to group the currently known 50 bidiverticulate Fridericia species (including the new species) in a somewhat different way, primarily on the basis of spermatheca and diverticulum characteristics and shape but also taking into consideration other important traits. This classification has resulted in two larger groups (I and II), of which the second includes five subgroups (II.1; II.2; II.3; II.4.; II.5). Characteristics of species belonging to the individual groups are listed in nine tables. This presentation offers an easy method of comparison of morphologically similar species by providing a good overview of all important traits. The detailed description of the species can be found in the excellent monograph by Schmelz (2003).

• Group I. The proximal parts of the two spermathecal ampullae are fused forming one common opening towards the oesophagus (10 species) ( Tables 1, 2).

• Group II. Separate openings of the proximal parts of the spermathecal ampullae into the oesophagus (39 species).

• Group II.1. The spermathecal diverticula are globular or hemispherical, sessile or with short stalks (11 species) ( Tables 3, 4)

• Group II.2. The spermathecal diverticula are globular or oval with welldeveloped stalks (seven species) ( Table 5).

• Group II.3. The spermathecal diverticula are ear-shaped and sessile (four species) ( Table 6).

• Group II.4. The spermathecal diverticula are elongated or sac-like, mostly bent distally. The diverticula and the distal parts of ampullae form a common U-shaped chamber (10 species) ( Tables 7, 8).

• Group II.5. Elongated or finger-shaped diverticula bent proximad, sometimes the two diverticula bent in opposite directions, but never distad together (seven species) ( Table 9).

Explanation of abbreviations and notations in the tables

Oesophageal appendage: type a: mostly short, unbranched or with few short terminal branches; type b: long, unbranched, usually much coiled; type c: much branched ( Nielsen and Christensen 1959). Coelomo-mucocytes: type a: outline wavy without refractile vesicles, type b: with refractile vesicle at the periphery, cell matrix mostly hyaline; type c: matrix pale vesicular, the outline of the cells smooth;?: detailed information neither in the original description of species nor in Schmelz (2003). Length of worms reported from living animals. Twenty-seven of the 48 figures of spermathecae are my own drawings, in the following cases the figures were drawn subsequent to the description by authors mentioned below: F. alata ( Nielsen and Christensen 1959); F. argillae , F. healyae , F. dozsae , F. auritoides , F. granosa , F. humicola ( Schmelz 2003) ; F. aurita ( Issel 1905) ; F. brachiata ( Rota 1994) ; F. chongquingensis (Xie at al. 1999); F. discifera ( Healy 1975; Schmelz 1999); F. heliota (Rota at al. 2003); F. larix ( Schmelz and Collado 2005) ; F. monochaeta ( Rota 1995) ; F. montafonensis ( Schmelz 1998) ; F. multisegmentata ( Wang et al. 1999) ; F. nanningensis (Xiel at al. 2001); F. omeri ( Stephenson 1932) ; F. stephensoni ( Moszyński 1933) ; F. ulrikae ( Rota and Healy 1999) ; F. viridula ( Issel 1904) .

opening Issel, 1904; Fridericia connata Bretscher, 1902 ; Fridericia monochaeta Rota, 1995 ; Fridericia brunensis

Rota and Healy, 1999.

common Fridericia profundicola Dózsa-Farkas, 1991 .

*after Springett (1971) and Schmelz (2003) (¤) on the basis of types materials; † F. sohleni was synonymised with

(2003) but Erséus et al. (2005) did not accept that; in central and southern Europe another form was found (

(not shown here), see Rota et al. (1998).

nix Rota,1995 ; Fridericia discifera Healy, 1975 ; Fridericia chongquingensis Xie, Liang and Wang, 1999 ; Fridericia

perrieri (Vejdovsky, 1878) ; Fridericia ulrikae Rota and Healy, 1999 ; Fridericia healyae Schmelz, 2003 ; Fridericia

Stephenson, 1932; Fridericia . galba (Hoffmeister, 1843) .

* After Southern (1907); † after Schmelz (2003); ̓ it is a complex of sexual and parthenogenetic lineages with

and presence or absence of one (rarely two) characteristical accessory glands. Specimens with only 2 diverticula

, 1899;

auritoides Schmelz, 2003 ; Fridericia aurita Issel, 1905 .

shaped chamber: Fridericia maculata Issel, 1905 ; Fridericia maculatiformis Dózsa-Farkas, 1972 ; Fridericia

Schmelz, 2003; Fridericia tubulosa Dózsa-Farkas, 1972 ; Fridericia . lenta Schmelz, 2003 .

shaped chamber: ( Fridericia brachiata Rota, 1994 ; Fridericia sardorum Cognetti, 1901 ; Fridericia multisegmentata

christeri Rota and Healy, 1999 .

distad: Fridericia heliota Zalesskaya, 1990 ( Rota et al. 2003); Fridericia conculcata Dózsa-Farkas, 1986 ; Fridericia

Fridericia sylvatica Healy, 1979 ; Fridericia bubalus Sesma and Dózsa-Farkas,1993 ; Fridericia nanningensis

humicola Bretscher, 1900 ).

Figures

Figure 1. Fridericia lacii sp. nov. (A) Oesophageal appendage, (B) coelomocytes, (C) sperm funnel, (D) nephridium, (E) spermatheca. Scale bar represents 50 Mm except in (B) where the line represents 25 Mm.

Figure 2. Fridericia lacii sp. nov. (A, B, E, H) Micrographs from stained whole mounts, (C, D) micrographs from living specimens. (A, E–G) Photographs from holotype. (A) Head (brain marked with arrow), (B) blood vessels in anterior segments, (C) chylus cells (marked with white arrows) in KX–KXII (sperm funnel marked with black arrow), (D) dorsal view of segments IV–VI with pharyngeal glands (marked with white arrows) and spermathecae (only the left clearly visible, marked with black arrow), (E) dorsal view of segments IV–VI: pharyngeal glands (marked with white arrows) with distinctly visible posterior projection (marked with black arrow), (F) the end of the deeper-stained gut cells in XIX, (G) intestine in XIII–XX: the deeper-stained part seen between the black arrows, (H) head with small papillae on prostomium (sensory organs?) (marked with black arrow). Scale bar represents 50 Mm except in (G) and (H) where lines represent 100 Mm.

Figure 3. Fridericia lacii sp. nov. (A, B, F) Micrographs from stained whole mounts, (C–E) micrographs from living specimens. (A) Clitellar glands (dorsal view), (B) clitellar glands (ventrolateral view), male copulatory organs marked with white arrows, (C) sperm funnel (marked with white arrow), (D) segment XI, sperm funnels marked with white arrows, (E) spermatheca in segments IV–VI (lateral view), diverticula marked with black arrows, spermathecal duct marked with white arrow and ectal gland with black line, (F) spermathecae in segment V, diverticula marked with black arrows (on the left side, only one diverticulum visible), spermathecal ducts marked with white arrows and ectal gland with black line. Scale bar represents 50 Mm.