Eisenia nordenskioldi shenzi, Qin & Zhao & Zhang & Han & Shekhovtsov & Wu & Aspe, 2025

Qin, Mingyan, Zhao, Huifeng, Zhang, Yufeng, Han, Anne Charis N., Shekhovtsov, Sergei V., Wu, Donghui & Aspe, Nonillon M., 2025, Description of three new subspecies of Eisenia nordenskioldi (Annelida: Crassiclitellata) from Northeastern China, Zootaxa 5642 (3), pp. 225-244 : 229-230

Eisenia nordenskioldi shenzi ssp. nov.

Material examined. Holotype: 1 clitellate ( 471R30_01 ), municipal park (46.6271°N, 131.1461°E, 141.5 m elev.), Beixiu Park , Shuangyashan City, Heilongjiang Province, 2023-07-15, coll. Yufeng Zhang.

Paratypes: 2 clitellates ( 464R_01, 04 ), Qianjin Town (49.1039°N, 125.2375°E, 281.0 m elev.), Nenjiang County, Heihe City , Heilongjiang Province, 2021-08-04 ; 4 clitellates ( 471R30_03 , 04 , 05 , 07 ), same data as of holotypes; 3 clitellates ( 507N_01 , 03 , 507R13_05 ), municipal park (42.3893°N, 126.8258°E, 575.2 m elev.), Liuhaishan Park , Jingyu County, Tonghua City, Jilin Province, 2023-07-23, coll. Huifeng Zhao.

Etymology. This subspecies is named after the Chinese adjective ‘dark purple’ translated into English, “shenzi” that describes its coloration.

Diagnosis. Pigmentation of the entire dorsal side is dark-purple except the clitellum (xxv, xxvi–xxxiii), which is gray, ventro-anterior to xv is purple,>xv is pale in alcohol. Body is small-medium size, length 38–81 mm diameter 5.32–6.5 mm, segments 78–156. Prostomium open epilobic. Dorsal pores from 4/5. Spermathecal pores paired in 9/10/11 close to mid-D. Female pores in xiv and male pores in xv lateral. Clitellum within xxv, xxvi–xxxiii, Tubercula pubertatis within ½xxviii, xxix–xxxi. Spermathecae has two pairs within ix–xi, the shape is spherical near the dorsal midline.

Description: Pigmentation of the entire dorsal side is dark-purple except the clitellum (xxv, xxvi–xxxiii), which is gray, ventro-anterior to xv is purple,>xv is pale in alcohol. Length 38–81 mm (n= 10). Diameter 5.32–6.5 mm. Segments 78–156. Prostomium open epilobic. Dorsal pores from 4/5. Setae closely paired. Setal ratio on segment viii in adult specimens: aa: 1.74–2.20; ab: 0.23–0.39; bc: 1.40–1.70; cd: 0.21–0.36; dd: 5.22–7.00; U (circumference): 7.85–13.66; mean: aa:ab:bc:cd:dd = 1.95: 0.34: 1.54: 0.27: 6.30; U: 10.73. Setal ratio on segment xxviii in adult specimens: aa: 2.74–3.80; ab: 0.23–0.43; bc: 1.17–1.53; cd: 0.20–0.26; dd: 5.16–5.91; U (circumference): 13.19– 16.64; mean: aa:ab:bc:cd:dd = 3.23: 0.33: 1.39: 0.24: 5.50; U: 15.33. Setal ratio on segment xli in adult specimens: aa: 2.13–2.79; ab: 0.24–0.36; bc: 1.57–1.94; cd: 0.19–0.29; dd: 4.71–6.00; U (circumference): 12.81–14.85; mean: aa:ab:bc:cd:dd = 2.46: 0.29: 1.77: 0.25: 5.31; U: 13.65. Nephropores alternate irregularly between setae b and above d. Spermathecal pores paired in 9/10/11 close to mid-D. Distance between spermathecal pores 0.037 (average of ten samples). Female pores in xiv lateral of b. Distance between female pores 0.195 (average of ten samples). Male pores in xv lateral of b just wider than female pores. Distance between male pores 0.240 (average of ten samples). One specimen has genital markings on the ventral side: a pair in vii, a pair in viii, one genital marking on the left of x and xi, a pair in xii Lateral: a pair of genital markings in viii–x; one genital marking on the right of xi. Clitellum saddle-shaped; in xxv–xxxiii (N= 4 specimens) or xxvi–xxxiii (N= 6). Tubercula pubertatis in ½ xxviii–xxxi (N= 2) or xxix–xxxi (N= 8).

Internally, septa 7/8–10/11 thickened. Spermathecae round, some specimens spermathecae are oval-shaped in ix, white; spermathecal duct short, thin in ix and x. Testis and funnels in x and xi seemingly free. Hearts in vii–xi. Calciferous glands xi and xii. Seminal vesicles four pairs in ix–xii (biggest in xii). Extraoesophageal vessels, the testis sacs and epididymis are absent. Ovaries compact in xiii. Crop in xv–xvi and muscular gizzard in xvii–xviii, some specimens in xvii–xxix. Spermathecae two pairs, 1 pair in each of 9/10 and 10/11, spermathecal shape spherical positioned near the dorsal midline. Typhlosole is inverted T-shaped from about xxvii.

Remarks. Eisenia species that are found in the Palearctic biogeographic region include Eisenia sibirica , E. lagodechiensis , E. nana , E. ventripapillata , E. atlavinyteae , E. angusta , E. balatonica , E. fetida , E. tracta , and E. nordenskioldi . Among these, Eisenia nordenskioldi has a thicker body (3.57–6.5 mm) than E. nana (2.5–3 mm), E. angusta (2.5–3 mm) and E. balatonica (1.5–2.5 mm) diameter. The first dorsal pore in E. nordenskioldi is located at 4/5, a characteristic shared with E. atlavinitae , E. angusta , and E. Balatonica ( Table 4 ). This positioning differs from E. fetida , which exhibits the first dorsal pore at both 3/4 and 5/6. The clitellum of E. nordenskioldi starts at segment xxiv, which differs from the starting position of the clitellum in E. sibirica (xxvii–xxxii), E. lagodechiensis (xxv– xxxiv), E. nana (xxvii–xxxiii), E. ventripapillata (xxvi–xxxiii), E. atlavinitae (xxvi–xxxiii), E. tracta (xxvi–xxxiii) and E. angusta (xxvii–½xxxiii). Additionally, the clitellum of E. nordenskioldi terminates at segment xxxiv, which is distinct from the ending position of the clitellum observed in E. balatonica (xxiv–xxx) and E. fetida (xxiv–xxxiii). Tubercles in E. nordenskioldi starts in segments xxvii, unlike any other Eisenia species. The distribution of papillae in E. nordenskioldi (ab vii–xiii, xvi–xviii, xxi–xxxv, cd viii–xiii) is more extensive compared to the other species like E. sibirica (ab viii, xxviii–xxxi, cd ix–xi), E. lagodechiensis (ab xxv–xxxviii, cd ix–xi), E. nana (ab viii–xii, cd x–xi), and E. ventripapillata (ab x–xi, xxvi–xxxii, cd x–xi). The calciferous glands in E. nordenskioldi are located on segments xi–xii without diverticula, similar to E. angusta and E. atlavinitae , but differ from E. balatonica and E. fetida . E. balatonica , which have diverticula on segments xi–xii. Eisenia fetida has its calciferous glands on x–xii without diverticula.

Among the subspecies, E. n. shenzi ssp. nov. overlaps in size with E. n. nordenskioldi , E. n. polypapillata, E. n. jilinensis, and E. n. chinensis but is relatively shorter than E. manshurica , E. n. mongol and E. n. onon (38–81 mm vs. 80–144 mm) ( Table 5 ). The new subspecies has a thicker body (5.32–6.5) compared with E. n. jilinensis and E. n. chinensis (3.57–5.1) ( Table 5 ). The entire dorsal side of E. n. shenzi is dark-purple except the clitellum, which is gray, whereas, the ventro-anterior side up to segment xv is purple, of which after, the rest is pale ( Fig. 1 ). On the other hand, the dorso-anterior side of E. n. jilinensis to segment xv is pinkish and gradually changes to pale throughout the rest of the ventral side. Meanwhile, both the entire dorsal and ventral sides of E. n. chinensis have pale pigmentation. The clitellum of E. n. shenzi starts from segment xxv while the clitellum of the rest of the consubspecifics start from either xxiv, ½xxv, ½xxvi, or xxvi. Similar to E. n. polypapillata and some specimens of E. n. chinensis, the TP starts at ½ of segment xxviii. The TP of the other subspecies begins at segment xxvii, xxviii or xxix. The setae ratio in segment viii, xxviii and xli in E. n. shenzi are significantly wider than that of E. n. jilinensis and E. n. chinensis. In addition, specimens of E. n. shenzi have the gizzard from xvii to xix, but the other two subspecies from xvii–xviii.

Figures

FIGURE 1. Body color characteristics of the three subspecies of Eisenia nordenskioldi. the dorsal and ventral coloration of (a and d) E. n. shenzi ssp. nov., (b and e) E. n. jilinensis ssp. nov. and (c and f) E. n. chinensis ssp. nov., respectively.