Fridericia jeoksangsaniensis, Dózsa-Farkas & Nagy & Felföldi & Hong, 2022

Dózsa-Farkas, Klára, Nagy, Hajnalka, Felföldi, Tamás & Hong, Yong, 2022, Four new enchytraeid species (Enchytraeidae, Annelida) from a Korean mountain (Jeoksangsan), Zootaxa 5094 (2), pp. 234-260 : 244-247

publication ID	https://doi.org/ 10.11646/zootaxa.5094.2.2
publication LSID	lsid:zoobank.org:pub:86B2DB64-22B5-424A-81DC-91790DC4B209
DOI	https://doi.org/10.5281/zenodo.6301532
persistent identifier	https://treatment.plazi.org/id/C44F87E9-FFC5-FFB3-FF6E-06E8FCD5FC39
treatment provided by	Plazi
scientific name	Fridericia jeoksangsaniensis
status	sp. nov.

Treatment

Fridericia jeoksangsaniensis sp. n.

( Figures 2D–E View FIGURE 2 , 8 View FIGURE 8 )

Type material. Holotype: NIBRIV0000886167, slide No. 3020 a+b, adult specimen, stained, whole mount. Type locality: Jeoksangsan , Jeoksang-myeon, Muju-gun, Jeollabuk-do, Korea, soil and litter layers of Pinus densiflora and mixed forests, N 35 ˚56′58.63″, E 127 ˚40′26.90″, 387 m asl, 06.11.2019 . Paratypes: NIBRIV0000886168, slide No. 3019 a+b, NIBRIV0000886169, slide No. 2887 (DNA ID 1412 ), adult specimens, stained, whole mount from type locality. P. 140.1–140.2., 2 adult, fixed, stained, whole mounts, slides No. 2927, 2922 and P.140.3, slide No. 3021 (DNA ID 1398 ), adult, not stained whole mounts, from type locality .

Etymology. Named after the mountain where it was found.

Diagnosis. The new species can be recognized by the following combination of characters: (1) large body size (22–39 mm long, 0.68–1.0 mm wide at clitellum, the cuticle <1µm in vivo), segments 49–87; (2) maximum 4–5 chaetae per bundle; (3) clitellum girdle-shaped, gland cells arranged in dense transverse rows, in the ventral midline more granulocytes than hyalocytes; (4) five preclitellar pairs of nephridia, 6/7–10/11; (5) coelomo-mucocytes type c, lenticytes very scarce; (6) chylus cells in XVII–XXIV (3–4 segments); (7) seminal vesicle in X–XI; (8) subneural glands absent; (9) sperm funnel cylindrical, about 2/3 as long as body diameter in vivo; (10) spermathecae with very long ectal duct, without ectal glands, the spherical ampulla large (diameter 120–200 µm, in vivo), distal parts of ampullae fused with one common opening into oesophagus.

Description. Holotype 34.5 mm long, 810 µm wide at VIII and 950 µm at clitellum in vivo (17.5 mm long, 770 µm wide at VIII and 820 µm at clitellum, fixed), segments 70. Body length of paratypes 22–39 mm, width 680–1005 µm at VIII and 730–1008 µm at clitellum, in vivo, length of fixed specimens 13–20.4 mm, width 710–920 µm at VIII and at clitellum, 800–1030 µm, segments 49–87. Chaetal formula: 2,3(1.4) – 2,3 (4): (2,3),4,5–4,(5),3. As in other Fridericia species , outer chaetae within a bundle longer and thicker than inner chaetae (e.g., 80–90 × 8 μm vs. 28–55 × 6 μm, preclitellar bundles ventrally). Chaetae of lateral bundles slightly smaller and thinner than ventrals (about 75–80 × 7 and 55 × 4 μm), chaetae largest in terminal segments (about 100–105 × 10–12 μm). Head pore at 0/I, well developed. Dorsal pores from VII. Epidermal gland cells arranged in 4–5 transverse rows per segments. Clitellum in XII–1/3XIII, girdle-shaped, hyalocytes and granulocytes arranged in dense rows, more granulocytes than hyalocytes ( Fig. 8A,B View FIGURE 8 ), between the male copulatory organs almost exclusively granulocytes ( Fig. 8C,D View FIGURE 8 ). Body wall thick, 80–100 µm, cuticle 2 µm, fixed.

Brain egg-shaped, about 240 μm long, when fixed, 1.6–1.7 times longer than wide. Oesophageal appendages ( Fig. 8G,H View FIGURE 8 ) with many short branches at the forepart and at the end. First pair of pharyngeal glands united dorsally, in V and VI the dorsal connection narrow or absent, all with ventral lobes. Chloragocytes from V. Dorsal vessel from XX–XXIV, blood colourless. Midgut pars tumida not seen. Five pairs of preclitellar nephridia from 6/7 to 10/11. Coelomo-mucocytes elongately oval, outline smooth, matrix pale but occasionally with some fine refractile granules, type c, length 50–80 µm ( Figs 2 View FIGURE 2 , 8E,F View FIGURE 8 ), lenticytes very scarce, 13-16 μm long in vivo, (40–56 µm and 10–15 µm when fixed, respectively). Chylus cells between XVII–XXIV, occupying 3–4 segments. Seminal vesicle in X–XI. Sperm funnels cylindrical ( Fig. 8I View FIGURE 8 ), 435–750 µm long in vivo, 2–3 times as long as wide (450–550 µm long and 1.6–3 times as long as wide when fixed). Collar slightly narrower than funnel body. Spermatozoa long, length 350–370 µm, heads not measurable in vivo. Male copulatory organs ( Fig. 8J View FIGURE 8 ) 300–500 µm long, 200–250 µm wide and 100–150 μm high, fixed. No subneural glands. Ectal ducts of spermathecae long, length 650–810 µm and width 25–30 µm, near ental bulb slightly wider (32–40 µm, fixed), ectal gland absent, epidermis glandularly thickened in a large field surrounding the orifice ( Figs 2 View FIGURE 2 , 8K View FIGURE 8 ). Ectal duct canal 4–5 µm wide. Ampullae large, onion-shaped without diverticula, diameter 120–200 µm, in vivo (fixed 125–180 µm), ental bulbs (90–100 µm wide, in vivo and fixed equally), projecting into the lumina of ampullae, sperm in circles round the bulbs. Distal and proximal parts of ampullae set off by a constriction. Proximal parts of ampullae (180–250 µm in vivo and 140–170 µm long, fixed) fused entally with one common opening into oesophagus ( Figs 2 View FIGURE 2 , 8L,M View FIGURE 8 ). 3–5 mature eggs at a time.

Distribution and habitat. Only known from type locality (Site 2): Jeoksangsan, Jeoksang-myeon, Muju-gun, Jeollabuk-do, Korea, soil and litter layers of Pinus densiflora and mixed forests, N 35˚56′58.63″, E 127˚40′26.90″, 387 m asl.

Differential diagnosis. Among all previously described Fridericia species , only F. dianchiensis Chen & Xie, 2008 from China shares the following character combination with the new species: more than 45 segments, onionshaped spermathecal ampulla without diverticula, and proximally fused ampullae with common opening into oesophagus.The main differences are as follows: F. jeoksangsaniensis sp. n. is larger [22–39 mm long, 730–1008 µm wide at clitellum, (49) 63–87 segments vs. 10–20 mm long, 440–520 µm wide and 59-65 segments in F. dianchiensis in vivo]; the coelomocytes are type c and larger 50–80 µm vs. type a and 20–30 µm; the spermathecal ectal ductus is longer and thicker (460-770 µm long, 30-33 µm wide vs. 400–500 µm and 25 µm in vivo, respectively); the locality of chylus cells are different (in XVII–XXIV vs. in XII–XIV).