Amynthas nanganensis nanganensis Shen & Chang

Shen, Huei-Ping, Chang, Chih-Han & Chih, Wen-Jay, 2015, Earthworms from Matsu, Taiwan with descriptions of new species of the genera Amynthas (Oligochaeta: Megascolecidae) and Drawida (Oligochaeta: Moniligastridae), Zootaxa 3973 (3), pp. 425-450 : 427-429

Amynthas nanganensis nanganensis Shen & Chang , sp. nov. et ssp. nov.

( Figure 1 )

Holotype: Clitellate (mature) specimen (137 mm in total length, dissected), Nangan, Shengtien Reservoir, 26°09'13.9''N, 119°54'59.7''E, 70 m asl, 28 May 2012, H.P. Chen & T.L. Ai (TESRI-O-H-43; MTS 12).

Paratype: 1 clitellate, Nangan, from Motianling Path, 26°09'41.2''N, 119°57'15.1''E, 142 m asl, 28 August 2012, H.P. Chen & H.H. Huang (TESRI-O-P-38; MTS 138).

Other material. 13 specimens altogether. 2 clitellates, Nangan, Hanlinjiao, from roadside ditches, 26°10'28.9''N, 119°55'01.7''E, 39 m asl, 25 June 2012, H.P. Chen & W.J. Chih (TESRI-O- 2012-58 -2; MTS 84); 5 clitellates, Nangan, Stronghold No. 12, 26°10'02.5''N, 119°57'06.2''E, 59 m asl, 25 June 2012, H.P. Chen & W.J. Chih (TESRI-O- 2012-60 -2); 3 clitellates, Nangan, from a roadside ditch in Nioubei Ridge, 26°09'44.5''N, 119°56'53.1''E, 138 m asl, 28 August 2012, H.P. Chen & H.H. Huang (TESRI-O-2012-116-1; MTS 139); 3 clitellates, Nangan, Shengtien Reservoir, 26°09'13.9''N, 119°54'59.7''E, 70 m asl, 28 August 2012, H.P. Chen & H.H. Huang (TESRI-O-2012-117-1; MTS 140).

Diagnosis. Small to medium; length (clitellates) 81–145 mm. Segments numbering 101–129. Setae 54–70 in VII, 56–84 in XX, and 18–25 between male pores. First dorsal pore in 12/13. Spermathecal pores dorso-lateral, two pairs in 7/8/9, 0.35–0.42 body circumference dorsally apart, with 2–16 tiny papillae arranging transversely or irregularly anterior to each pore. Male pores 0.3–0.35 body circumference ventrally apart in XVIII, each on a small, round porophore surrounded by 6–17 papillae. Genital papillae absent in the mid-ventral region. Spermathecae two pairs in VII and IX, or in VIII and IX. Diverticulum coiled. Seminal vesicles large, two pairs in XI and XII. Prostate glands large in XVI–XX. Prostatic duct U-shaped in XVIII. Accessory glands stalked, mushroom-like, corresponding to external genital papillae.

Description. External: Total length (clitellates) 81–145 mm. Weight 0.63–1.89 g. Segments numbering 101– 129. Clitellum XIV–XVI, setae 0–20 in XIV, 0–21 in XV, and 0–22 in XVI, dorsal pores absent, length 3.42–5.63 mm and width 3.5–4.2 mm. Prostomium epilobous. Setae 54–70 in VII, 56–84 in XX, and 18–25 between male pores in XVIII. First dorsal pore in 12/13. Spermathecal pores dorso-lateral, two pairs in intersegmental furrows of 7/8/9; distance between paired pores 0.35–0.42 body circumference dorsally apart, with 2–16 tiny papillae arranging transversely or irregularly anterior to each pore ( Fig. 1 A), rarely 1–2 papillae posterior to the pore. Female pore single, mid-ventral in XIV. Male pores inconspicuous, paired in XVIII, 0.3–0.35 body circumference ventrally apart, each situated on a small, round porophore surrounded by 6–17 papillae, enclosed laterally by one to three shallow skin folds ( Fig. 1 B). Genital papillae absent in the mid-ventral region. Preserved specimens dark brown or dark blackish brown on dorsum, brown to grayish brown on ventrum, and dark brown to grayish brown on clitellum.

Internal: Septa 5/6–7/8 thick, 10/11–13/14 muscular, 8/9/10 absent. Nephridial tufts on anterior faces of 5/6/7. Gizzard large in VIII–X. Intestine enlarged from XV. Intestinal caeca paired in XXVII, extending anteriorly to XXIV, each simple, wrinkled, distal end either straight or bent. Esophageal hearts in X–XIII. Spermathecae two pairs in VIII and IX ( Fig. 1 C), or in VII and IX, ampulla peach-shaped or elongated oval-shaped, surface wrinkled, 1.86–1.9 mm long and 1.1–1.31 mm wide, spermathecal stalk short, stout, 0.45–0.6 mm in length. Diverticulum coiled with a slender and straight proximal part. Accessory glands stalked, mushroom-like, 0.6–0.95 mm in total length, each corresponding to external genital papilla ( Fig. 1 C). Holandric, testes small, two pairs in ventrally joined sacs in X and XI. Seminal vesicles large, smooth, two pairs in XI and XII, anterior pair rectangular-shaped, extending anteriorly to the posterior half or the entire compartment of segment X, posterior pair elongated ovalshaped, with a round dorsal lobe at the dorso-anterior end. Prostate glands large in XVI–XX ( Fig. 1 D), wrinkled and lobed. Prostatic duct long, stout, U-shaped in XVIII. Accessory glands stalked, mushroom-like, about 0.6 mm in total length, corresponding to external genital papillae ( Fig. 1 D).

DNA barcodes. GenBank accession numbers KJ782568 (MTS 12, holotype), KJ782573 (MTS 138, paratype), KJ782567 , KJ782574 , and KJ782575 (MTS 84, 139 and 140, respectively).

Etymology. The name nanganensis is given to this species with reference to its type locality of the island of Nangan.

Figures

FIGURE 1. Amynthas nanganensis nanganensis sp. nov. et ssp. nov. Holotype (TESRI-O-H- 43). A. Right-lateral view of right spermathecal pore region (gp, genital papilla; sp, spermathecal pore). B. Ventral view of male pore region (mp, male porophore). C. Dorsal view of right spermathecae (shaded area) (amp, ampulla; dv, diverticulum; ag, accessory gland). D. Dorsal view of right prostate gland (pd, prostatic duct). Scale bars = 1 mm.