Amynthas konkakinh Nguyen, Lam & Nguyen, 2022

Grzelak, Katarzyna & Sørensen, Martin V., 2022, Echinoderes blazeji Grzelak & amp; Sørensen 2022, sp. nov., Zoological Studies 55 (52), pp. 1-13 : 10-12

Amynthas konkakinh Nguyen, Lam & Nguyen

sp. nov. lsid:zoobank.org:act: 833AA0A9-E3EF-4AE4-9F87- 9C75E84696A7 ( Fig. 6 , Table 1)

Material examined: Holotype: One mature ( CTU-EW038 -p01) primary forest, southwestern part of Kon Ka Kinh National Park, Gia Lai province, Vietnam, 20/10/2010, coll. Pham Thi Mai.

Diagnosis: Large-size worm, length ca. 670 mm, diameter ca. 16.5 mm. First dorsal pore in 12/13. Prostomium epilobous. Spermathecal pores round and small, ventrally paired in intersegmental furrows 5/6/7/8/9. Male pores located in xviii, without copulatory pouches. Genital makings present on both spermathecal and male regions (on viii and xviii). Holandric. Spermathecal ampulla cylindrical-shaped, duct short; diverticula coiled. Testis sacs separated. Intestinal caeca simple. Septa 8/9/10 absent.

Etymology: “ konkakinh ” is a noun in apposition to emphasize the type locality.

Description: External characters: Body cylindrial, length 670 mm, diameter 16.5 mm (20 mm /viii, 15 mm /xvi, 16 mm /xviii, 15 mm /xxx), segments 204, weight 119.68 g. Dorsa blackish grey, but ventra paler. Prostomium epilobous. First dorsal pore large, in 12/13. Setae perichaetine, short; pre-clitellar setae stouter and sparser than post-clitellar setae, 131 in v, 144 in viii, 187 in x, 219 in xx, 226 in xxv, 208 in xxx, 50 between male porophores in xviii; setal distance aa = ab, zz = 1.0-2.0zy. Clitellum annular, xiv-1/2xvii, blackish brown, smooth and without setae and dorsal pores. Female pore single, mid-ventral in xiv. Spermathecal pores very small, ventrally paired in intersegmental furrows 5/6/7/8/9, hardly visible externally. A genital marking ventrally present on viii. Male pores directly opened in xviii; ventral distance between male porophores about 0.35x body circumference. A pair of genital markings present in front of setal ring of xviii, slightly medial to male pores.

Internal characters: Septa 4/5/6/7/8 very thickened, 8/9/10 absent, 10/11/12/13 thin. Oesophageal gizzard within viii-x. Intestinal origin at xv; caeca simple, originating at xxvii and extending anteriorly to xxii. Last hearts in xiii. Pharyngeal micronephridia developed in 5/6/7. Lymph glands present from 32/33. Typhlosole simple, lamelliform, poorly developed. Spermathecae paired ventrally in vi- ix. Spermathecal ampulla cylindrical-shaped; duct short, about 1/3 ampulla length. Diverticula very shorter than ampulla, opalescent, coiled, directly attached to base of ampulla. Accessory glands absent. Holandric. Testis sacs separated, in x and xi. Seminal vesicles whitish yellow, poorly developed within xi-xii. Oviduct poorly developed on septum 12/13 posteriorly; ovaries developed in 13/14. Prostate glands racemose, paired within xviii; prostatic ducts strong, slightly getting smaller distally. A pair of accessory glands present.

Habitat: The species was collected from soil surface or litter layer in the rich forest. It can be epigeic species.

Remarks: The new species can be classified into the diffringens species group characterised by holandric and four pairs of spermathecal pores in intersegments 5/6/7/8/9 ( Sims and Easton 1972). However, it can be distinguished by its large size and pattern of genital markings in spermathecal and male regions.

Amynthas konkakinh sp. nov. is especially similar to A. antoanensis sp. nov. by having large size, first dorsal pore in 12/13, four pairs of spermathecal pores in 5/6/7/8/9, intestinal caeca simple, septa 8/9/10 absent, and prostomium epilobous ( Table 1). However, A. antoanensis sp. nov. can be recognized from A. konkakinh sp. nov. by having four pairs of genital markings in viii and ix, and two pairs of genital markings in mid-ventral xviii.

The new species is also fairly similar to the other large Amynthas earthworms from Vietnam, Amynthas dangi ( Thai, 1984) and A. munglonganus ( Thai & Tran, 1986) , by its very large size, holandric, prostomium epilobous, septa 8/9/10 absent, last hearts in xiii, and copulatory pouches absent. However, A. dangi differs from the new species in having two pairs of spermathecal pores in 7/8/9, a genital marking closed to the male pore and an additional three pairs of genital markings on ventral xviii and xix. A. munglonganus is distinguished from the new species by the first dorsal pore in 12/13, three pairs of small genital markings located closely to spermathecal pores in 5/6/7/8, a medium genital marking next to the male pore, and different shape of spermathecal ampulla.

Key to large earthworms in Vietnam

1. Four pairs of spermathecal pores in 5/6/7/8/9 .................. 2

- Only two or three pairs of spermathecal pores ................. 3

2. Genital markings paired in viii, ix, and mid-ventral xviii. Spermathecal ampulla oval-shaped ........... A. antoanensis

- Genital markings single in viii, and paired in front of male pores in xviii. Spermathecal ampulla cylindrical .................. ............................. ........................................... A. konkakinh

3. Two pairs of spermathecal pores in 7/8/9 ............. A. dangi

- Three pairs of spermathecal pores in 5/6/7/8 or 6/7/8/9 ..... ........................................................................................... 4

4. Spermathecal pores in 6/7/8/9 .......................... A. ghilarovi

- Spermathecal pores in 5/6/7/8 .......................................... 5

5. Genital markings absent in both spermathecal and male pore regions ............................................ A. munglonganus

- Genital markings present in both spermathecal and male pore regions ........................................... A. munglongoides

Figures

Fig. 6. Amynthas konkakinh sp. nov., holotype. A, F: Male pore region, ventral view (mp = male pore; gm = gential markings); H: Spermathecal region (sp = spermathecal pore; gm = gential markings); C, E: Spermathecae (amp = ampulla; dv = diverticula); D, G: Intestinal caeca; B: Prostatic gland (ag = accessory gland). Scale bar = 1 mm.