Amynthas nametensis, 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 : 243

Amynthas nametensis sp. nov.

( Figure 2A,B )

Material. Holotype: clitellate ( BDNUL0038 ): Laos, Hoaphane Province , Nam Et-Phouley NBCA, Viengthong district, Thad Ang waterfall area, 792 m (20o 15.446'N, 103o 0 8.921' 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 ( BDNUL0039 , ( BDNUL0040 ), same data as for holotype . Other material: 3 clitellates, 6 aclitellates, same data as for holotype .

Etymology. The species is named for its type locality near Nam Et.

Diagnosis. Spermathecal pores paired in 7/8, 8/9 at 12th–13th setal lines; male pores superficial on thickened circular pads, surrounded by one white convex outer ring in XVIII at 10th setal line, 0.24–0.27 circumference ventrally apart, elevated genital papillae in line with male pores presetal in XVIII, XIX; first dorsal pore at 12/13, large typhlosole, intestinal origin in XVI, spermathecal diverticula coiled into dense irregular block.

Decription. Dimensions 78–100 mm, by 5.0–6.0 mm at segment X, 4.8–5.5 mm at segment XXX, 4.5–4.6 mm at clitellum; body cylindrical, segments 121–136. Setae evenly distributed around segmental equators, numbering 58–64 at VII, 63–70 at XX, 2–6 between male pores, setal formula AA:AB:ZZ:YZ= 4:2:4:1 at XIII. Female pore single at XIV on an oval porophore 0.5–0.6 mm in diameter. Prostomium epilobic with tongue open, unpigmented except I–VIII, clitellum light brown, formalin preservation. First dorsal pore at 12/13. Clitellum annular XIV–XVI; setae invisible externally. Male pores superficial on circular thickened areas, surrounded by one white outer ring at lateral margins of ventrum in XVIII at 10th setal lines, 0.24–0.27 circumference apart ventrally. Elevated genital papillae in line with male pores presetal in XVIII, XIX. Spermathecal pores paired in 7/8, 8/9 at 12th–13th setal lines, 0.29–0.37 circumference apart ventrally; conspicuous bumps below mid-lateral.

Septa 5/6–7/8 very thick, 8/9 thin, 9/10 muscular, 10/11 thin, 11/12 thick, 12/13 thin. Gizzard globular in VIII. Intestine enlarged from XVI, lymph glands not found. Typhlosole very deep fold from XXIV. Intestinal caeca simple originating in XXVII and extending anteriorly about to XXII, simple finger-shaped. Hearts esophageal X– XIII; X small. Male sexual system holandric, testes and funnels in annular sacs in X, XI; sacs enclose all other segmental organs. Seminal vesicles paired in XI, XII, small. Prostates in XVIII, and extending from XVII–XXIII; long stout ducts coiled, glandular portions consisted of 2 main lobes each divided into 2–3 small lobes. Ovaries in XIII. Spermathecae paired in VII, VIII; ampulla medium size globular-shaped, duct much shorter than ampulla, diverticulum tubular, iridescent, coiled into irregular ovate block like a large oval chamber, stalk much shorter than ampulla, no nephridia on spermathecal ducts.

Remarks. Amynthas nametensis sp. nov. is unusual in the present collection because it has annular testes sacs, first dorsal pore in the more typical Amynthas location of 12/13, an intestinal origin in XVI rather than XV, a very well-developed typhlosole which starts before the caeca, and septa 8/9/10 present and thickened to some degree. Amynthas choanus and A. uanus have dorsal pores in 12/13 and 10/11, respectively, but the former has genital markings in VII and VIII and the latter has C-shaped male porophores.

Figures

FIGURE 2. Amynthas nametensis sp. nov. (A,B), Amynthas somechanae sp. nov. (C,D), and Amynthas wiggeri sp. nov. (E,F). A,C,E: ventral view; B,D,F: spermatheca. Scale bars 2 mm.