Amynthas chandyi, Hong, Yong, 2008

Hong, Yong, 2008, Two new bithecal earthworms of the genus Amynthas (Oligochaeta: Megascolecidae) from Laos, Zootaxa 1914, pp. 57-61 : 59-61

Amynthas chandyi sp. nov.

(Fig. 2A–B)

Material. Holotype: clitellate ( BDNUL 0002): Laos, Xayabouli Province, Nam Phouin NBCA, Phou vang Phan (18o 29.878’N, 101o 28.870’E), 495 m, 5 km from village in old forest, black soil with sand, in soil and litter layers, 30 August 2005, K. Inkhavilay and Chandy colls. 4 paratypes: 2 clitellates ( BDNUL 0 0 0 5, 0006) and 2 clitellates ( NIBR), same data as for holotype. Other material: 10 clitellates, same data as for holotype. Etymology. The species is named after its type collector.

FIGURE 2. Amynthas chandyi sp. nov. A: ventral view; B: spermathecae. Scale bars = 2.5 mm (A), 1 mm (B).

Diagnosis. Spermathecal pores one pair in 7/8 at 6th seta within conspicuous ventral round spots; male pores superficial at 4th–6th seta on circular porophores, 0.14–0.32 circumference apart ventrally; genital papillae paired on XVIII and 18/19 posterior to the male porophore, single mid-ventral at some of the following locations: postsetal XVI–XIX, presetal XVIII, XX. holandric, first dorsal pore at 5/6.

Description. Dimensions 29–58 mm by 2.0–3.0 mm at segment X, 2.3–3.2 mm at segment XXX, 2.0–3.0 mm at clitellum; ventrum slightly flat, segments 48–52. Setae more crowded ventrally, numbering 44–54 at VII, 44–57 at XX, 0–7 between male pores, setal formula AA:AB:ZZ:YZ= 1:1:4:2 at XIII. Female pore single in XIV, on an oval area 0.2–0.3 mm in width. Prostomium epilobic with tongue open, clitellum coffee color, dorsal dark purple-brown pigment, fading posteriorly, formalin preservation. First dorsal pore at 5/6. Clitellum annular XIV–XVI; setae invisible externally.

Male pores superficial at 4th–6th setae on circular, presetal porophores anterior to dark equatorial genital papillae in slightly sunken area, 0.14–0.32 circumference apart ventrally; distance between male pores 1.5– 2.4 mm. Number and location of genital papillae irregular, usually paired on XVIII and 18/19 posterior to the male porophore, single mid-ventral at some of the following locations: postsetal XVI–XIX, presetal XVIII, XX. Spermathecal pores one pair in 7/8 at 6th seta within conspicuous round spots, 0.13–0.23 circumference apart ventrally; distance between spermathecal pores 1.2–1.5 mm. Genital markings circular in various locations, paired or single mid-ventral in VII, VIII; usually 3 or 4 in total number.

Septa 5/6–7/8 thin, 8/9, 9/10 absent, 10/11–13/14 very thin. Gizzard globular in VIII–X. Intestinal origin in XV, lymph glands not found. Typhlosole low fold from XXVII. Intestinal caeca originating in XXVII, extending anteriorly about to XXIV, simple finger-shaped. Hearts esophageal in X–XIII. Holandric; testes and funnels in ventrally joined sacs in X–XI. Seminal vesicles paired in XI–XII with small dorsal lobes in clefts. Prostates in XVIII, extending between XVII–XXI; glands consisting of 2 main lobes each divided again into 2–4 small lobes; prostatic ducts slender, muscular in one loop. Genital marking glands not found.

Ovaries in XIII. Spermathecae one pair in VIII; ampulla irregularly flattened, wrinkled by gizzard, stout ducts shorter than ampulla with thick muscular proximal section, thinning and narrowing in the distal section toward body wall, diverticulum chamber flattened, iridescent, with slender stalk shorter than ampulla, attached to thick section of the spermathecal duct, no nephridia on ducts. Genital marking glands not found.

Remarks. Amynthas chandyi sp. nov. appears to be closely related to Amynthas namphouinensis sp. nov., but A. namphouinensis has no genital markings near the spermathecal pores. By having genital markings near the spermathecal pores, A. chandyi is more like the larger A. xuongmontis (90 mm x 3.5 mm). On the other hand, A. chandyi has mid-ventral genital papillae in several locations between XVI and XX, while A. xuongmontis only has a single mid-ventral papilla in XVIII. Other differences from A. xuongmontis include the much smaller number of segments in A. chandyi .