Amynthas antethecus, Hong & Inkhavilay & James, 2018

Hong, Yong, Inkhavilay, Khamla & James, Samuel W., 2018, Nine new species of the " aeruginosus " - group in Amynthas (Clitellata: Megascolecidae) from Nam Et-Phouley National protected Area, Laos, Zootaxa 4496 (1), pp. 238-250 : 247-249

Amynthas antethecus sp. nov.

( Figure 3C,D )

Material. Holotype: clitellate ( BDNUL0050 ): Laos, Hoaphane Province , Nam Et-Phouley NPA, Viengthong district, Thad Ang waterfall area, 792 m (20o 15. 446' N, 103o 08– 921' E), good condition mossy forest with big trees, dark soil and thick litter layer, 21 July 2005, Phimphet, Xay, Ammaline, Phoang sone, and K. Inkhavilay colls . Paratypes: 2 clitellates ( BDNUL0051 , BDNUL0052 ), same data as for holotype . Other material: 25 clitellates, same data as for holotype .

Etymology. The species is named for the anteriorly shifted spermathecae, being in segments VII and VIII rather than VIII and IX as is usual for earthworms with spermathecal pores in 7/8/9.

Diagnosis. Secondary male pores near lateral margins of ventrum in XVIII at 10th setal lines, 0.31 circumference apart ventrally, sphincter-like; primary male pore on small penis within shallow parietal invagination; paired circular papillae within invaginations on 17/18, 18/19, medial to level of secondary male pores; spermathecal pores paired in 7/8/9 at 9th setal lines, pores large, 0.21 circumference apart ventrally; first dorsal pore in 5/6; very large fusiform muscular prostatic ducts in single loop bound together with tough fibers.

Description. Dimensions 88–122mm, by 4.0– 4.1 mm at segment X, 3.2–3.8 mm at segment XXX, 3.0– 3.8 mm at clitellum; body cylindrical, segments 82–109. Setae slightly more crowded ventrally, numbering 59–63 at VII, 56–61 at XX, 12–14 between male pores, setal formula AA:AB:ZZ:YZ= 1:1:3:2.5 at XIII. Female pore single in XIV, on a circular porophore 0.5–0.6 mm in diameter. Prostomium epilobic with tongue open, clitellum light brown, anterior dorsal brown pigment, formalin preservation. First dorsal pore at 5/6. Clitellum annular XIV–XVI, setae invisible externally. Secondary male pores near lateral margins of ventrum in XVIII at 10th setal lines, 0.31 circumference apart ventrally, opening surrounded by tubercular wrinkled epidermal ring; primary male pores on small cylindrical penis within shallow parietal invaginations. Paired circular papillae on 17/18, 18/19, medial to level of secondary male pores. Spermathecal pores paired in 7/8/9 at 9th setal lines, pores large, 0.21 circumference apart ventrally.

Septa 5/6/7/8 thinly muscular, 8/9/10 absent, 10/11 thin, 11/12/13 /14 thinly muscular. Gizzard globular in VIII–X. Intestine enlarged from XV, lymph glands not found. Typhlosole vestigial from XXVII. Intestinal caeca originating in XXVII extending anteriorly about to XXIII, simple elongate triangle. Hearts esophageal X–XIII, X smaller. Male sexual system holandric, testes and funnels in ventrally joined sacs in X, XI. Seminal vesicles paired, well-developed in XI, XII; dorsal lobes lacking. Prostates in XVIII, extending from XVII–XX; stout fusiform muscular ducts bent in one loop tightly bound together by tough fibers; glandular portions consisted of 10–14 small digitate lobes. Dense sessile genital papilla glands corresponding to papillae of 17/18, 18/19. Ovaries in XIII. Spermathecae paired in VII, VIII; ampulla irregular, bent down and attached to side of duct, muscular ducts shorter than ampulla, iridescent seminal chamber ovate, with slender stalk shorter than ampulla; stalk joined duct near ampulla base, no nephridia on ducts.

Remarks. This species is in the aeruginosus -group Laotian section, generally characterized by long prostatic ducts often in mirror-image coils, first dorsal pores in 5/6 or nearby, and lack of pre-clitellar genital markings. Amynthas antethecus sp. nov. has been compared to Amynthas fleischmani sp. nov. under the remarks for that species. The two are closely sympatric, found on the same site, with no intermediate forms. Our placement of it in Amynthas rather than in Metaphire is justified in the remarks on the previous species.

Figures

FIGURE 3. Amynthas fleischmani sp. nov. (A,B), Amynthas antethecus sp. nov. (C,D), and Amynthas elenabondae sp. nov. (E,F). A,C,E: ventral view; B,D,F: spermatheca. Scale bars 2 mm.