Eisenia sp.

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 : 10-11

Eisenia sp.

Material examined: North Korea, Myohyang Mt. Wonhan Peak ca. 1500 ma. s. l. 06.1985, 1 ex. leg. Z. Tóth ( HNHM /16901)

Description: External characters. Length 71 mm, diameter 6 mm. Number of segments 104. Colour red-violet alive, bleaching out during preservation. Prostomium epilobous. First dorsal pore at intersegmental furrow 4/5. Setae closely paired. Setal arrangement behind clitellum: aa: ab: bc: cd: dd = 15:1.8:9.5:1:30 ( Fig. 12 ). Male pores on segment 15, surrounded by small glandular crescents, confined into its own segment. Nephridial pores irregularly alternate between setal line b and above d. Clitellum on segments 25- ½32 but segment 23 and 24 also slightly modified. Tubercula pubertatis on segments ½27-30. Genital papillae on 10 cd, 12, 17, 25-31 ab.

Internal characters: No septa notably thickened. Testes and funnels paired in segments 10-11, free. Seminal vesicles in 9, 11, 12, those in 9 somewhat smaller than the others. Spermathecae drop-shaped in 9/10-10/11 with external openings close to the mid-dorsal line. Ovarium in 13, elongated. Ovarian funnel with undulated rim, ovisac small, pending from 13/14 just above the ovarian duct. Calciferous glands in 11-12 with moderate diverticula. Paired hearts appear in segments 7-11, with a pair of small

Zoological Studies 55: 12 (2016)

extraoesophageal vessel in 12. Nephridial bladders simple, sausage-shaped. Crop in segments 15- 16, and gizzard in segments 17-18. Typhlosole bilobed, moderate. Longitudinal muscle layer is of pinnate type.

Remarks: Unfortunately the only specimen at hand shows sign of regeneration before the male pore. However as all the inner organs are in the correct position we assume that the clitellar data is correct. This species is similar to E. kucenkoi Michaelsen, 1903 in the position of the clitellum and the distribution of genital papillae. However, E. kucenkoi is proandric (1 pair of testis in 10) and the present specimen possesses longer tubercles. It is slightly similar to E. koreana and the two recently described species E. gaga Blakemore & Park, 2012 and E. sindo Blakemore & Park, 2012 however differs from all the three species in the position of the tubercles (27-29 vs. ½27-30) and the number of seminal vesicles (9-12 vs. 9, 11, 12). Another difference is that the present specimen lacks the characteristic quadrangular shape which is typical for all the three species mentioned. Most probably this specimen represents a new still undescribed species however, for the formal description additional material is needed.

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Figures

Fig. 12. Eisenia sp. 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.