Amynthas hoauykanangensis, 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 : 241-242

Amynthas hoauykanangensis sp. nov.

( Figure 1C,D )

Material. Holotype: clitellate ( BDNUL0033 ): Laos, Hoaphane Province , Nam Et-Phouley NPA, Viengthong district, summit of Phouley Mountain, 2273 m (20o16.323'N, 103o11.772'E), in wet, thick organic surface layers, 23 July 2005, Boutong, Phimphet, Son and K. Inkhavilay colls . Paratype: 1 clitellate ( BDNUL0034 ), same data as for holotype .

Etymology. The species is named for its type locality near Hoauy Kanang Mountain.

Diagnosis. Male pores superficial at lateral margins of ventrum in XVIII at 7th setal lines, 0.19–0.25 circumference apart ventrally; pores medial to centers of approximately circular thickened pads; spermathecal pores two pairs in 7/8–8/9 at 11th setal lines; paired round genital papillae postsetal on XVII and presetal on XIX in line with male pores, two genital papillae lateral to each male porophore, one presetal and the other postsetal; first dorsal pore 4/5 or 5/6, prostatic ducts coiled clockwise (L) and anticlockwise (R).

Description. Dimensions 63–77 mm, by 4.0 mm at segment X, 3.0 mm at segment XXX, 3.7–3.8 mm at clitellum; segments 87–102. Setae regularly distributed around segmental equators, numbering 51–52 at VII, 46– 51 at XX, 11–12 between male pores, setal formula AA:AB:ZZ:YZ= 1:1:1:1 at XIII. Female pore single in XIV, on an oval porophore 0.4 mm in diameter. Prostomium epilobic with tongue open, clitellum coffee color, red-brown pigment on segments I–XIII dorsal, ventral; formalin preservation. First dorsal pore at 5/6 (1), or 4/5 (1). Clitellum annular XIV–XVI; setae invisible externally. Male pores superficial at lateral margins of ventrum in XVIII at 7th setal lines, 0.19–0.25 circumference apart ventrally; pores medial to centers of approximately circular thickened pads. Paired round genital papillae postsetal on XVII and presetal on XIX in line with male pores, two genital papillae lateral to each male porophore, one presetal and the other postsetal. Spermathecal pores paired in 7/8–8/9 at 11th setal lines, inside segmental furrow at lateral margins of ventrum within white area, 0.27–0.34 circumference apart ventrally. Genital markings lacking in preclitellar segments.

Septa 5/6–7/8 thinly muscular, 8/9, 9/10 absent, 10/11–12/13 thinly muscular. Gizzard globular in VIII–X. Intestine enlarged from XV, lymph glands not found. Typhlosole small from XXVII. Intestinal caeca originating in XXVII and extending anteriorly about to XXIV, simple elongate triangle. Hearts esophageal in X–XIII. Male sexual system holandric, testes and funnels in ventrally joined sacs in X, XI. Seminal vesicles paired, welldeveloped with no dorsal lobes in XI, XII. Prostates in XVIII, extending through XVII–XIX; glandular portions divided into 3 main lobes; muscular ducts in clockwise (L) and anticlockwise (R) spirals. Genital papilla glands not found. Ovaries in XIII. Spermathecae two pairs in VIII, IX; ampulla globular, almost flattened by gizzard, very muscular ducts shorter than ampulla, seminal chamber ovate, iridescent, slightly curved stalks shorter than ampulla, bound to body wall, no nephridia on spermathecal ducts. Genital marking glands not found.

Remarks. See the previous species remarks for distinctions between the new species and A. aeruginosus . Amynthas hoauykanangensis sp. nov. is similar to A. phimpheti sp. nov. (see below) but it differs in the locations and numbers of genital papillae and the structure of the male field. Amynthas hoauykanangensis sp. nov. has two small round genital papillae just lateral to each porophore and paired papillae post-setal in XVII and presetal in XIX, but A. phimpheti sp. nov. has one pair of genital papillae on 17/18, and one pair pre-setal in segment XIX. The male pores of A. hoauykanangensis sp. nov. are superficial at the 7th setal lines on small round porophores, but A. phimpheti sp. nov. has large circular male pads surrounded by outer rings, with pores at the 8th setal lines. Amynthas hoauykanangensis sp. nov. has spermathecae in VIII and IX, but A. phimpheti sp. nov. has spermathecae in VII and VIII, even though the pores are in 7/8/9.

Figures

FIGURE 1. Amynthas bouatongi sp. nov. (A,B), Amynthas hoauykanangensis sp. nov. (C,D), and Amynthas phimpheti sp. nov. (E,F). A,C,E: ventral view; B,D,F: spermatheca. Scale bars 2 mm.