Eisenia koreana ( Zicsi, 1972 )

Hong, Yong & Csuzdi, Csaba, 2016, New data to the earthworm fauna of the Korean Peninsula with redescription of Eisenia koreana (Zicsi) and remarks on the Eisenia nordenskioldi species group (Oligochaeta, Lumbricidae), Zoological Studies 55 (12), pp. 1-15 : 5-7

Eisenia koreana ( Zicsi, 1972)

Eiseniella koreana Zicsi, 1972: 129 .

Eisenia koreana : Perel 1979: 82.

Eisenia koreana : Easton 1983: 480.

Eisenia koreana : Blakemore and Park: 2012: 299.

Material examined: Holotype. HNHM/12715 with label data: Eiseniella koreana sp. n. typus, Phenjan, 22.V.1970. Leg. S. Mahunka u. H.

Zoological Studies 55: 12 (2016)

Steinmann., Paratypes. HNHM /7000 3 adult + 2 preadult complete specimen, 2 adult specimen with missing tail, 1 juvenile and 1 tail part with label: Eiseniella koreana paratypus, Phenjan 22. V.70. Leg. S. Mahunka u. H. Steinmann.

New material: North Korea. Haeju, Su-Yong waterfall, 16.07.1988. Leg. Cs. Csuzdi ( HNHM /16919 1 juv. ex).

Redescription: External characters. Holotype 44 mm long and 2.8 mm wide. Number of segments 100. Paratypes 41-52 mm long and 2.8- 3 mm wide. The tail is prominently quadrangular. Number of segments 125-130. Colour pale with slight hints of previous pigmentation. Prostomium epilobous ½ closed. First dorsal pore at intersegmental furrow 4/5. Setae closely paired. Setal arrangement behind clitellum: aa: ab: bc: cd: dd = 5.7:1.2:5.2:1:8.6 ( Fig. 3 ). Male pores on segment 15, surrounded by glandular crescents, slightly protruding into segments 14 and 16. Female pores as small slits on 14, just above the setae b. Nephridial pores irregularly alternate between setal line b and above d. Clitellum on segments 25-31 but segment 24 also modified slightly ( Fig. 4 ). Tubercula pubertatis as glandular trench on segments 27-⅔29, 29 ( Fig. 5 ). Genital papillae on Holotype; 10 cd, 10 ab Rhs, 11 cd, 16, 26-28, 30

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ab. Paratype 1; 11 cd, 9, 10 ab Rhs, 11 cd Lhs, 16, 25, 30. Paratype 2; 23 ab Rhs, 17 ab Lhs, 11 cd, 16, 26-28, 30 ab. Spermatophore at 22/23 on Holotype.

Internal characters: Septa 7/8-8/9 thickened, 6/7, 9/10-10/11 slightly strengthened, and also 12/13-14/15 somewhat stout. Testes and funnels paired in segments 10-11, free. The entalmost part of the sperm ducts somewhat coiled and slightly thickened. Seminal vesicles in 9-10 small, 11- 12 larger. Spermathecae drop-shaped in 9/10- 10/11 with external openings close to the mid-dorsal line. Ovarium in 13, elongated and slightly flattened. Ovarian funnel large, with undulated rim, ovisac small, pending from 13/14 just above

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the ovarian duct. Calciferous glands in 11-12 with slightly more developed diverticula in segment 12. Paired hearts appear in segments 7-11, with a pair of small extraoesophageal vessel in 12. Nephridial bladders simple, slightly elongated sac-shaped ( Fig. 6 ). Crop in segments 15-16, and gizzard in segments 17-18. Typhlosole bilobed, moderate ( Fig. 7 ). Longitudinal muscle layer is of pinnate type.

Remarks: On the basis of the gizzard (in 17- 18) and the position of the female pores (above setae b) koreana is surely fits into the genus Eisenia (e.g. Perel 1979, Easton 1983) and seems to be very close to E. gaga Blakemore, 2012 (in Blakemore & Park 2012) described from Gageodo Island, S. Korea. The only substantial differences found from this species are the size and segment number (41-52 × 2.8- 3 mm vs. 80-105 (diameter not noted in gaga ) and 100-130 vs. 124-162). E. koreana is close also to E. sindo Blakemore, 2012 from Sindo Island, Incheon, S. Korea but differs from it in the smaller biometry and presence of a typhlosole (lacking in sindo ). As the two recently described species were mainly defined by their DNA barcodes, adequately preserved North page 7 of 15

Korean specimens would needed to clear the relationship between E. koreana , E. sindo and E. gaga .

Figures

Fig. 3. Eisenia koreana (Zicsi, 1972) setal arrangement. aa = distance between the ventral setal lines, ab = distance between the ventrolateral setal lines, cd = distance between the dorsolateral setal lines, dd = distance between the dorsal setal lines.

Fig. 4. Eisenia koreana (Zicsi, 1972) ventrolateral view of the fore-body.

Fig. 5. Eisenia koreana (Zicsi, 1972) ventrolateral view of the clitellar region.

Fig. 6. Eisenia koreana (Zicsi, 1972) nephridial bladder.

Fig. 7. Eisenia koreana (Zicsi, 1972) typhlosole. dv = dorsal vessel.