Fridericia granulocyta, Dózsa-Farkas, Klára, Felföldi, Tamás & Hong, Yong, 2015

Dózsa-Farkas, Klára, Felföldi, Tamás & Hong, Yong, 2015, New enchytraeid species (Enchytraeidae, Oligochaeta) from Korea, Zootaxa 4006 (1), pp. 171-197 : 184-185

Fridericia granulocyta sp. n.

( Figures 6 D – G, 8)

Type material. Holotype. NIBRIV0000320523, slide No. 1094, adult, stained and whole-mounted specimen. Type locality: site 7: Dongjin-myeon, Buan-gun, Jeollabuk-do, Korea, 35º46'04.6"N 126º43'14.8"E, 23 m asl, soil of agronomical fields, leg. Y. Hong, 19.05.2014.

Paratypes. NIBRIV0000320524, slide No. 2026, adult stained whole mounted specimen. Locality: site 11: Sulchon-myeon, Muju-gun, Jeollabuk-do, Korea, 35º59'28.7"N 127º50'46.8"E, 544 m asl, mixed forest, leg. Y. Hong, 16.05.2014. P.106. 1–5, slides No. 2007–2010, 2016. 2 adult and 3 subadult stained whole mounts, from type locality, leg. Y. Hong, 19.05.2014. P.106.6–106.8, slides 2024, 2025, 2027. 3 adult whole mounts, stained specimens, from site 11, Sulchon-myeon, Muju-gun, Jeollabuk-do, Korea, 35º59'28.7"N 127º50'46.8"E, 544 m asl, mixed forest, leg. Y. Hong, 16.05.2014.

Further material examined. 4 subadult specimens from type locality.

Etymology. Named after the granulated coelomo-mucocytes.

Diagnosis. The new species can be recognized by the following combination of characters: (1) Medium-sized worms (7–12 mm, in vivo), segments 40–47; (2) maximum 5 (6) chaetae per bundle; (3) clitellum girdle-shaped, between male openings only granulocytes; (4) five preclitellar pairs of nephridia; (5) all pharyngeal glands with ventral lobes; (6) coelomo-mucocytes type b, lenticytes scarce; (7) chylus cells in XII–XIV (2 segments); (8) seminal vesicle absent; (9) subneural glands absent; (10) sperm funnel small, barrel-shaped, collar narrower as funnel body; (11) spermathecae with onion-shaped ampullae (diameter 34 – 47 µm, in vivo) without diverticula, separate opening into oesophagus, spermathecal ectal duct somewhat shorter than body diameter, no ectal glands.

Description. Holotype 8.5 mm long, 320 µm wide at VIII and 330 µm at clitellum, fixed, 44 segments. Body length of paratypes 7–11.5 mm, width 290 – 380 µm at VIII and 300–400 µm at clitellum, in vivo. Length of fixed specimens 6–12 mm, width 300–400 µm at VIII and 310–420 µm at clitellum. Segments 40–47. Chaetal formula: 3,4 – 4,3,2: 4,5,(6) – 5.4,3,2. Largest chaetae in preclitellar bundles 55 – 60 x 5 µm, intermediate-sized chaetae 48 – 50 x 5 µm, smaller inner chaetae 25 – 35 x 4 µm. At body end chaetae measuring 65– 75 x 5–6 µm. Chaetae in XII absent. Head pore at 0/I. Dorsal pores from VII. Epidermal gland cells arranged in 1–3 transverse rows per segment, often one or two rows per segment brown-colored. Clitellum in XII–1 /2XIII, girdle-shaped. Gland cells arranged in rows, between male openings only granulocytes. Thickness of body wall about 32–42 µm, cuticle about 2 µm in fixed specimens.

Brain egg-shaped, about 120 Μm long (fixed) and 1.7 times longer than wide ( Fig. 8 A). Oesophageal appendages type a, with some small branches at the end ( Fig. 6 D). First pair of pharyngeal glands united dorsally, the secondary and third pairs separate dorsally (sometimes all three separate), all with ventral lobes the smallest lobes in IV. Chloragocytes from V about 14–20 Μm long, in vivo. Dorsal vessel from XVI–XVIII, blood colourless. Midgut pars tumida not seen. Five pairs of preclitellar nephridia from 6/7 to 10/11, anteseptale large, length ratio anteseptale: postseptale 1: 1.3–1.4, adseptal origin of efferent duct, no terminal vesicle ( Fig. 8 G). Coelomomucocytes ( Figs. 6 E, 8C) broadly-elliptical, cell periphery with refractile granules, type b, length 22–40 Μm, lenticytes scarce, 5–9 Μm long, in vivo. Chylus cells between XII–XIV, occupying 2 segments. Seminal vesicle absent. Sperm funnels mostly barrel-shaped, small ( Figs. 6 G, 8E,G), about 90–150 µm long and 1.5–1.8 times as long as wide, in vivo. Funnel length in fixed specimens about 100 µm. Collar 12–20 Μm, high and narrower than funnel body. Spermatozoa about 80–160 µm long, heads 40–60 µm, in vivo ( Fig. 8 G). Diameter of sperm ducts 5– 7 µm, fixed. Male copulatory organs ( Fig. 8 D,E) small 70–90 µm long, 60 µm wide and 30–40 (70) Μm high, fixed, modiolus distinct, muscular sheath weakly developed, bursal slits longitudinal, bent laterally. Subneural glands absent. Spermathecae ( Figs. 6F , 8 H,I): ectal ducts slightly shorter than body diameter, about 200–250 µm long and 12–14 µm wide, in vivo (170–210 µm, fixed), no ectal glands at the orifice. Ampullae onion-shaped without ental bulb in ampullae and without diverticula, diameter 34–47 µm, in vivo and 27–45 µm, fixed. Proximal parts of ampullae 35–42 µm long (in vivo, fixed), communication with oesophagus separate but close to each other dorsolaterally. One or two mature eggs at a time.

Distribution and habitat. In Korea site 7: Dongjin-myeon, Buan-gun, Jeollabuk-do, 35˚46’04.6”N 126˚43’14.8”E, 23 m asl, agronomical fields, and site 11: Sulchon-myeon, Muju-gun, Jeollabuk-do, 35˚59’28.7”N 127˚50’46.8”E, 544 m asl, mixed forest.

Differential diagnosis. Considering the shape of spermathecae with separate openings into the oesophagus, this new species is similar to 13 Fridericia species: F. c al l o s a ( Eisen, 1878) sensu Schmelz (2003), F. parathalassia Schmelz, 2002 , F. peregrinabunda Michaelsen, 1913 , F. s i m a Welch, 1914, F. sphaerica sp. n., F. seoraksani Christensen & Dózsa-Farkas, 2012 , F. b e nt i Schmelz, 2002, F. bulbosa (Rosa, 1887) sensu Rota (2015) , F. rara Rota, 2015 , F. meridiana Rota, 2015 , F. tuberosa Rota, 1995 , F. nielseni Möller, 1971 , F. unisetosa Xie et al., 2000 ( Schmelz 2003; Christensen & Dózsa-Farkas 2012; Rota 2015; Xie et al. 2000).

The main differences between the first five species and the new species are body size (10-20 mm long), higher segment number and a larger diameter of the spermathecal ampullae. Moreover, F. ca l l o s a has type c oesophageal appendagees, F. parathalassia has only four pair nephridia preclitellarly, in F. peregrinabunda the maximum of chaetae is two per bundle, F. sphaerica sp. n. has longer spermathecal ectal ducts, and in F. si ma the maximum number of chaetae per bundle is 7–8. The smaller F. benti , F. rara and F. nielseni have a maximum of only two chaetae per bundle; moreover, F. benti has a larger spermathecal ectal gland, in F. bu l bo s a the maximum of chaetae is four and the coelomo-mucocytes type a. F. rara has only three pairs of preclitellar nephridia, F. meridiana has only 4 pairs of preclitellar nephridia, the penial (=bursal) slits are T-shaped and chylus cells occur preclitellarly; in F. nielseni the clitellum is saddle-shaped. F. tuberosa is similar to the new species by the b type coelomocytes but has only 4 pairs of preclitellar nephridia and subneural glands. In F. unisetosa the dorsal chaetal bundles are absent. Finally, F. loretensis and F. seoraksani are the most similar species to F. granulocyta , but F. loretensis has more segments (51–55), pharyngeal glands in IV are without ventral lobes and the dorsal lobes in VI have a posterior bulge projecting into VII. F. seoraksani is somewhat larger (8–15 mm), coelomocytes are type a (not type b) and the sperm funnel is cylindrical and more than two times longer than wide.

Figures

FIGURE 8. Micrographs of F. granulocyta sp. n. A. Brain. B. Chaetae, ventral view. C. Coelomocytes, type b. D. Male copulatory organs, ventral view. E. Sperm funnel (black arrow), male copulatory organ (white arrow), lateral view. F. Clitellar glands of holotype, ventral view; between the bursal slits (= pb) only granulocytes (white arrow); female pores marked with black arrows. G. Sperm funnel (white arrow) and adjacent nephridium; its adseptal origin of ectal duct marked with black arrow. H – I. Spermathecae; long ectal ducts marked with white arrows, ampullae marked with black arrows (pg = pharyngeal glands). A – D, G, H in vivo, E, F, I fixed, stained. Scale bars 50 µm.

FIGURE 6. F. cusanicaformis sp. n. (A – C), F. granulocyta sp. n. (D – G), and Mesenchytraeus calyx sp. n. (H – K). F. cusanicaformis: A. Spermathecae. B. Coelomocytes. C. Sperm funnel. F. granulocyta: D. Oesophageal appendage. E. Coelomocytes. F. Spermatheca. G. Sperm funnel. Mesenchytraeus calyx: H. Brain of adult specimen. I. Sperm bundle. J. Spermatheca. K. Male copulatory organ (a = atrium; sd = sperm duct; ag = atrial glands; acg = accessory copulatory glands).