Fridericia alpica, Dózsa-Farkas & Felföldi, 2018

Dózsa-Farkas, Klára & Felföldi, Tamás, 2018, The Enchytraeid Fauna (Enchytraeidae, Clitellata) Of The Rax Mountain (Austria) With Description Of Two New Species And Comparison Of Fridericia Discifera Healy, 1975 And F. Alpica Sp. N., Acta Zoologica Academiae Scientiarum Hungaricae 64 (1), pp. 1-20 : 5-11

Fridericia alpica sp. n.

( Figs 1–2 )

Type material – Holotype. F. 26. slide No. 2136, Rax Mountain , close to the Rax cable car terminal, under Pinus mugo 47°43.233N, 15°45.164E, 1612 m a.s.l., 15.05.2012.

Paratypes.In total 13 specimens.P.110.1.1.slide No.2137 at the type locality. 15.05.2012; P.110.1.2–110.1.3, slides No. 2120, 2156, two specimens on Rax Mountain at the type local - ity, under Pinus mugo , 47°43.038N, 15°46.024E, 1623 m a.s.l. and 47°43.007N, 15°45.401E, 1613 m a.s.l., 22.05.2014; P.110.1.4-109.1.6 slides No. 2129, 2132–2133, three specimens, on Rax Mountain, near to type locality under Picea abies 47°43.012N, 15°46.317E, 1560 m a.s.l., 15.05.2015; P.110.2.1–109.2.2 slide No. 2118–2119 two specimens in Kőszeg Mts (Günzer Mts), near to Reichnitz, Austria, mixed forest ( Pinus silvestris , Picea abies , Quercus petraea , Fagus sylvatica ), 47°19.453N, 16°25.400E, 589 m a.s.l., 21.05.2014; P110.3.1–109.3.5 slides No. 2121–2123, 2157, 2159, five specimens in Kőszeg Mts near to Steirer Houses, Hungary, Quercus petraea woodland with some Fagus sylvatica 47°22.411N, 16°30.016E 521 m a.s.l.

Etymology – Named after the region where this species is an inhabitant of the eastern margin of Alps.

Diagnosis – The new species can be recognized by the following combination of characters: (1) medium size (7–16 mm in vivo), segments 38–52; (2) maximum 5–6 chaetae per bundle; (3) clitellum girdle-shaped: hyalocytes and granulocytes arranged in transverse rows; (4) five preclitellar pairs of nephridia; (5) coelomo-mucocytes numerous, a-type (according to MÖLLER 1971), lenticytes 7–12 μm; (6) chylus cells mostly in XVI–XVII; (7) bursal slit T or Y-shaped; (8) seminal vesicle large; (9) subneural glands in XIII–XV; (10) sperm funnel cylindrical, approximately half as long as body diameter, collar narrower as funnel body, sperm 150–220 Μm long, sperm heads 60–75 Μm long (fixed); (11) spermatheca separate entally, with two sessile, sphaerical diverticula and a large ectal gland.

Description – Holotype in vivo 6.9 mm long, 350 μm wide at VIII and 380 μm at the clitellum (fixed), 51 segments. Body length of the paratypes 7–16 mm, width 300–400 Μm at VIII and 340–400 μm at the clitellum (in vivo). Length of fixed specimens 4.7–11 mm, projections, spermathecae marked with black arrows, E = dorso-lateral view, F = dorsal view), G = third pairs of pharyngeal glands, ventral view (* = ventral projections), H = coe- lomocytes, I = male copulatory organs, J = bursal slit (marked with arrow). (A–C, E, G–H, J

in vivo, D, F, I fixed, stained; scale bars = 50 Μm)

width 270–380 μm at VIII and 310–430 μm at the clitellum. Segments 38–52. Chaetal formula: 2,(1),3,4,5 – 5,4,3,2: (1,2),3,4,5,6 – 6,5,4,3,2(1). As in other Fridericia species , chaetae in bundles arranged in pairs with the outer pair being longer and thicker than the inner pairs: 58–70 by 5–6 Μm against 43–60 by 4–5 Μm and 25–40 by 3 Μm (preclitellar bundles), at body-end only 2 (1) chaetae per bundle, length about 65–75 by 5–6 μm. Head pore at 0/I. Dorsal pores from VII. Epidermal gland cells weakly developed. Clitellum in XII–1/2XIII, girdle-shaped, hyalocytes and granulocytes arranged in transverse rows dorsally ( Fig. 1A ), glands ventrally mostly weakly developed only ( Fig. 1B ). Thickness of body wall about 30–60 Μm, cuticle about 1–1.5 Μm in vivo. Brain egg-shaped, about 140–160 μm long, 2 times longer than wide in vivo ( Fig. 1C ) and 120–140 Μm and 1.5 times longer than wide in the fixed specimens ( Fig. 1D ).

Oesophageal appendages, long, without branches. Pharyngeal glands in 4/5 united dorsally, with small ventral lobes, in 5/6 united dorsally or free with medium large ventral lobes, in 6/7 free dorsally with large ventral lobes and ventral projections ( Figs. 1E–G ). Chloragocytes from V, brown in vivo. Dorsal vessel from XVI–XXI, blood colourless. Midgut pars tumida in XXVII–XXXIII occupying 5–6 segments ( Fig. 2A ). Five pairs of preclitellar nephridia from 6/7 to 10/11, length ratio anteseptale: postseptale 1:1.5–2, midventral origin of efferent duct. Coelomo-mucocytes numerous, a-type (according to MÖLLER 1971) (length 29–42 Μm in vivo, (10–20 Μm fixed), lenticytes, 6–10 Μm long ( Fig. 1H ). Chylus cells between XVI–XVII, occupying 2 segments. Seminal vesicle large. Sperm funnels cylindrical ( Figs 2C, D ), about 150–280 Μm long and 2–3 times as long as wide (in vivo). Funnel length in fixed specimens 140–180 μm. Collar not narrower than funnel body. Spermatozoa about 200–300 Μm long, heads 70–150 Μm in vivo, in fixed specimens 150–220 Μm and 60–75 Μm, respectively. Diameter of sperm ducts 9–10 Μm (in vivo). Male copulatory organs ( Fig. 1I ) small 100–150 Μm long, 55–75 Μm wide and 45–55 Μm high (in vivo), (80–120, 50–70 and 40–45 μm in fixed specimens, respectively). Bursal slits T- or Y-shaped ( Fig. 1J ). Subneural glands in XIII–XV, the first are the largest ( Fig. 2B ). Spermathecae ( Figs 2E–F ): one 45–50 Μm long (in vivo) stalked ectal gland at the orifice ( Fig. 2F ), 35–57 Μm, fixed. Ectal ducts about 150–250 Μm long and 18–20 Μm wide, ectally slightly widening (20–30 Μm wide), projecting into ampullae, ental bulbs about 40–60 Μm wide, canals not widened. Each am- pulla with two rounded, mostly sessile diverticula, located on opposite sides at the am- pulla. The diameter of the diverticula 45–60 Μm, ampullae 60–80 Μm wide, proximal part of ampulla considerably set off from distal part by a constriction, 45–50 Μm long (fixed); separate openings into oesophagus. 2–3 mature eggs at a time.

Distribution and habitat – Austria: Rax Mountain in the habitats of mountain mead- ow and Pinus mugo and Picea abies stands, further Kőszeg Mts (Günser Mts) in mixed forest. Hungary: Kőszeg Mts near to Steirer Hauses, in Quercus petraea woodland with some Fagus sylvatica . The species lives presumably in the Alps and their foothills in the Western geographic region of Hungary.

Remarks – The new species can be well distinguished from all Fridericia species having two sessile spermathecal divericula and non-fused ampullae (see the Tables 3 –4 in DóZSA-FARKAS 2009 and DóZSA-FARKAS et al. 2015), ex- cept F. discifera . The differential diagnosis from this species is given below.

Comparison of F. alpica sp. n. and Fridericia discifera Healy, 1975 – The two species are very similar, so for their proper discrimination we have com- bined morphological and molecular methods. Previously SCHMELZ (2003) also indicated that some specimens found in the Alps and identified as F. discifera could belong to a yet undescribed Fridericia species. We found that the two above-mentioned species occur together both in the Rax Mt. and also in the Kőszeg Mts in Hungary, moreover F. alpica sp. n. was found in Hungary and also Austria (where this mountain range is called Günser Mountains).

We made a comparison on the basis of the descriptions of F. discifera by HEALY (1975) and SCHMELZ (1999) as well as based on specimens collected in this study. Many traits of the two species are very similar, the morphological comparison of the similar characters are given in Table 2. Dissimilar charac-

view (marked with arrows), B = subneural glands in XIII–XV (marked with arrows), C–D sperm funnels (in D marked with arrows, e = egg), E–F spermathecae (in F the large ectal

glands marked with arrows). (A–B, F fixed, stained, C–E in vivo, scale bars = 50 Μm)

ters are listed here. The maximum number of chaetae in a bundle is only 4 in F. discifera , but 5 or 6 in F. alpica . The body wall in both species has approxi- mately the same width (in our F. discifera 30–40 Μm, according to SCHMELZ (1999) only 20–25 Μm, in F. alpica the same or slightly thicker: 30–60 Μm), but the cuticle is in F. discifera much thicker, i.e. 5–9 Μm ( Fig. 3D ) than in F. alpica , where it has only 1–1.5 Μm (fixed). There are only 4 pairs of preclitel- lar nephridia in F. discifera , but 5 pairs in the new species. The mucocytes are very scarce and with hyaline matrix and small refractile vesicles at periphery in F. discifera ( Fig. 3F ) but numerous and of a-type (without refractile vesicle) in F. alpica ( Fig. 1H ). Lenticytes are of about the same length in both species. The pharyngeal glands are also slightly different: in F. alpica the first pair is connected dorsally and has small ventral lobes, the second pair is connected dorsally or free and has medium large ventral lobes, and the third pair is free dorsally, has large ventral lobes and projections backwards ( Figs 2E–G ). In F. discifera , the first pair of pharyngeal glands is of the same kind, the secondary pair is also similar, but always connected dorsally, the third pair is also simi- lar, but the projection absent ( Fig. 3E ). Both species have subneural glands, but in F. alpica in XIII–XV (in 3 segments) ( Fig. 2B ), whereas in F. discifera only in XIII–XIV (in 2 segments). The spermathecae are very similar ( Figs 2E–F and 3I ) either, except the ectal gland, which is larger (35–57 Μm long, fixed) and stalked in F. alpica ( Fig. 2F ) but only 17–25 Μm long and sessile in F. discifera ( Fig. 3I ).

ventrally (bursal slits marked with arrows), C = brain, D = body wall, thick cuticle (marked with arrow), E = pharyngeal glands dorsal view (marked with white arrows, no ventral

projections, spermathaecae marked with black arrows), F = coelomocytes, scarce, a/b-

type, G = male copulatory organs, H = sperm funnels, I = spermathaecae (small ectal gland

marked with arrow). (A–B, E–F, H in vivo, C–D, G, I fixed, stained; scale bars = 50 Μm)

Fridericia cf. discifera described by ROTA (1995) from Tuscany and Umbria, Italy, differs considerably from F. discifera proper, therefore SCHMELZ (1999) had the opinion that this is another, yet undescribed species. However, it also differs from F. alpica sp. n. The main differences are as follows: the oesophage- al appendages are branched whereas unbrached in F. alpica , the coelomocytes according to Figure 9C ( ROTA 1995) are c-type (according to MÖLLER 1971) and larger (maximum of 55 μm, whereas a-type and only 29–42 μm long in the new species). The spermathecal ectal ducts are much longer 520–550 Μm, whereas only 150–250 Μm in F. alpica .

Figures

Fig. 1. Micrograph of Fridericia alpica sp. n. A = clitellar glands dorsally, B = clitellar glands ventrally, C–D = brain, E–F = pharyngeal glands (marked with white arrows, * = ventral

Fig. 2. Micrograph of Fridericia alpica sp. n. A = midgut pars tumida in XXX–XXXI, lateral

Fig. 3. Micrograph of Fridericia discifera. A = clitellar glands dorsally, B = clitellar glands