Fridericia crassiductata, Dózsa-Farkas, K. & Cech, G., 2006

Dózsa-Farkas, K. & Cech, G., 2006, Description of a new Fridericia species (Oligochaeta: Enchytraeidae) and its molecular comparison with two morphologically similar species by PCR­RFLP, Zootaxa 1310, pp. 53-68 : 57-60

Fridericia crassiductata sp.n.

Type material deposited in the author’s (Dózsa­Farkas, K.) collection at the Department of Systematic Zoology and Ecology, Eötvös Loránd University, Budapest.

Type locality: Zemplén Mountains, Hungary,

Holotype: F.14 (1967) Senyő–völgy, Zemplén Mountains, picked up from beech litter, 48o28’22” N, 21o25’59” E 214m, 20.04.2004. coll. K. Dózsa­Farkas.

Paratype: P.81.1 (1968) Komlóska–völgy, Zemplén Mountains, 48o25’53”N, 21o27’30”E, 223m, purple moorgrass meadow, 28.05.2003, one stained specimen coll. K. Dózsa­Farkas, M. Pobozsny, P.81.2 (1969) Mlaka–rét, Zemplén Mountains, 48o24’04”N, 21o24’32”E, 497m, mixed hornbeam­birches forest, 28.05.2003, one stained specimen coll. K. Dózsa­Farkas, M. Pobozsny, P.81.3 (1970) Senyő–völgy, Zemplén Mountains, 48o28’22” N, 21o25’59” E, 214m from beech litter, 20.04.2004, three specimens, coll. K. Dózsa­Farkas, P.81.4 (1971) Senyő–völgy, Zemplén Mountains, oak forest ( Quercus cerris ) 48o28’19”N, 21o25’58” E 217m, 20.04.2004, three specimens, coll. K. Dózsa­ Farkas, P.81.5 (1972) Mlaka–rét, Zemplén Mountains, beech forest 48o23’59”N 21o24’21”E 542m, 0 5.28.2003, one prae­clitellar half of body (the caudal part used of DNA­based examinations (in Table 1:No. 1) coll. K. Dózsa­Farkas, M. Pobozsny, P.81.6 (1973) Bagolybérci gerinc, Zemplén Mountains, oak forest ( Quercus petraea ) 48o24’27’N 21o23’41”E 593m, 0 5.28.2003, one specimen, coll. Dózsa­Farkas, M. Pobozsny.

Etymology: ‘crassus’ (Lat.) = thick, ductus (Lat.) = duct, tube. Referring to the thick and long spermathecal ectal duct.

Description

Length 13–20 mm. Diameter 0.5–0.7 mm at VIII, and 0.6–0.8 mm at clitellum. Segment number (38) – 40 – 56. Chaetae ( Fig. 1 A) a maximum of 10 per bundle, formula ( Nielsen & Christensen 1959): 4,5,6,7 – 6,5,4,(3,2): 7,8,9,10 – 8,7,6,5,4,(3,2). Outer chaetae much longer than inner, e.g. the outermost 76 – 85 μm long and the innermost 33–38 μm in a prae­clitellar bundle, the outer 95–100 μm long and the inner 85–90 μm long at the caudal part of the body. Cutaneous glands: about 10 rows of brown reticulate cells per segment. The epidermis is often hard to see through, due to these brownpigmented cells on the anterior segments ( Fig. 1 B). Body wall of medium thickness (about 38–47 μm) cuticle thin (3 μm). Head pore at 0/I, well visible ( Fig. 1 C). Dorsal pores beginning from VII. Brain ( Fig. 1 D) 1.2–1.5 times longer than wide (140–180 μm long) in the postero­lateral regions one small aggregation of refractive globules on either side. Oesophageal appendage (peptonephridia) ( Fig. 2 A) variable, proximally some short branches, the main tube extends to V with wide lumen, and 1–2 branches distally. Sometimes the proximal branches cannot be found. Pharyngeal glands (septal glands) all paired with ventral lobes (in VI distinctly largest often with posterior projection), dorsal connection absent. Nephridia 5 pairs from VI/VII – X/XI, postseptale 2,5­times longer than the anteseptale, medial origin of efferent duct. Coelomocytes ( Fig. 1 E): mucocytes type b ( Möller 1971), small (20–24–32 μm) with refractile vesicle, often dark in transmitted light, lenticytes (length 5–11 μm) are scarce. Chylus cells not visible due to the dense dark chloragocytes. Dorsal blood vessel from (XV)–XVII–XVIII, blood colourless. Clitellum well developed, XII–XIII girdle shaped, hyalocytes and granulocytes arrangement reticulate ( Fig 3 ). Seminal vesicle is very large, occupying 3–4 segments (VIII–XII). Sperm funnel ( Fig. 4 A) 250–380 μm long and 140–160 μm wide, collar narrower than the funnel body. Spermatozoa about 264 μm long, head 95 μm. Male copulatory organ is 170–200 μm long, 80–140 μm wide and 80–120 μm high, the bursal slit ( Fig. 4 B) is longitudinal with more transverse components. Three small subneural glands ( Fig. 4 C) in the XIV–XV–XVI segment. The ectal duct of spermatheca ( Fig. 2 B, 5A) is very wide (35–48 μm) and long (580–640 μm), longer than the body diameter. The ectal duct canal is narrow (6–7 μm) throughout, and not widening proximally. Two (rarely three) large sessile eggshaped brown ectal glands (80–130 μm long, 60–75 μm wide) ( Fig. 5 B, 5C). The ampulla with a single ring of 9–10 large, sessile, globular diverticula (50–70 μm long), laterally compressed by each other, filled with sperm ( Fig. 5 A). Proximal part of ampulla cylindrical with a wide lumen. There is a separate opening into oesophagus. Two to four mature eggs at a time.

Distribution and habitat: Known only from the type locality (Zemplén Mountains [north­eastern part of the Hungarian Central Mountains]), in beech, hornbeam and birch forest).

Diagnosis

The new species can be recognized by the following combination of characters: (1) the size of the body (13­20 mm long, 0.5–0.7 mm wide, segment number (38)–40–56); (2) the form of spermatheca, with 9–10 large, sessile, globular diverticula, long and thick ectal ducts, and two very large (80–130 μm long) eggshaped ectal glands; (3) maximum ten chaetae per bundle; (4) all pairs of pharyngeal glands with ventral lobes and the dorsal connection absent; (5) the clitellum is girdle shaped, hyalocytes and granulocytes arrangement reticulate; (6) seminal vesicle is large; (7) penial slit is longitudinal with more transverse components; and (9) three subneural glands in XIV–XVI.

from F. ratzeli (Eisen, 1872) sensu Nielsen and Christensen, 1959 and F. eiseni Dózsa­ Farkas, 2005) in the following morphological properties: F. r a t z e l i ( Eisen, 1872 ) sensu Nielsen and Christensen, 1959 has only small spermathecal ectal glands, the coelomocytes type are between type a and type c (while the new species has two large ectal glands and type b of coelomo­mucocytes with refractile vesicle). F. eiseni were found to have tiny spermathecal ectal gland(s), the ectal duct is far thinner (24–26 μm compared to35–50 μm in F. crassiductata ), the spermathecal diverticula is more or less the same shape in the new species, whereas the size of the diverticula of F. eiseni is variable and the two lateral ones are always larger.

The shape of the spermatheca of F. crassiductata shows high morphological similarity with F. re g u l a r i s ( Nielsen and Christensen, 1959), however, the ectal duct is far more slender and the ectal gland is absent or very small (see Schmelz, 2003, Fig. 61A). Moreover, in the case of the latter species the oesophageal appendages are more coiled (type b) and the maximal chaetal number is four. Large Fridericia species with similar spermathecae ( F. regularis Nielsen and Christensen, 1959 , F. oconeensis Welch, 1914 , F. firma Smith and Welch, 1913 , F. agricola Moore, 1895 ) differ from the new species by the absence of the subneural gland(s). F. oconeensis differs from the new species by the thinner spermathecal duct and absent (or very small) ectal glands, furthermore, the small diameter of the spermathecal ampulla with diverticula (70 μm). Neither F. f i r m a, nor F. agilis Smith, 1895 and F. agricola possesses ectal glands of the spermatheca. In the case of F. agilis and all the four species mentioned above, the maximal number of chaetae does not reach 8 (it is 8–10 in the case of the new species). Finally, two other species described in Italy seem to be partly similar considering the spermatheca: F. gigantea Dequal, 1912 and F. florentina Dequal, 1914 . F. gigantea is much larger (30–45 mm long, 90–95 segments). Also, F. florentina has more segments (85–90) and although it has two large spermathecal ectal glands, the spermathecal duct is short and the diverticula of the spermatheca are placed in two groups on the opposite sides of the ampulla.

Figures

FIGURE 1. Fridericia crassiductata sp. n. A = setal bundles of a praeclitellar segment (lateroventral view), B = Photograph of the cutaneous glands of a praeclitellar segment (dorsal view), C = Photograph of the head (head pore marked with arrows), D = Photograph of the head (brain marked with arrows), E = Photograph of the coelomocytes. Each photograph is sized with a black line representing 50 μm length.

FIGURE 2. Fridericia crassiductata sp. n. A = oesophageal appendage, B = spermatheca.

FIGURE 3. Fridericia crassiductata sp. n. Fridericia crassiductata sp. n. Photograph of the clitellar glands (dorsal view).

FIGURE 4. Fridericia crassiductata sp. n. Fridericia crassiductata sp. n. A = praeclitellar segments (½ X – ½ XII) (sperm funnels marked with arrows, B = Photograph of bursal slits (marked with arrows) of the male copulatory organs, C = Photograph of the subneural gland in XIV (marked with arrow).

FIGURE 5. Fridericia crassiductata sp. n. A = Photograph of the spermatheca. (the diverticle fill with sperm around the ampulla marked with black arrows, the ectal duct with white arrows, ectal gland with asterisk, B = Photograph of the opening of spermathecal ectal duct (glands marked with black arrows, duct with white arrow), C = Photograph of the opening of spermathecal ectal duct three glands marked with black arrows, duct with white arrow).