Nine new species of the "aeruginosus"-group in Amynthas (Clitellata: Megascolecidae) from Nam Et-Phouley National protected Area, Laos

Abstract

Nine new species of Amynthas (Clitellata: Megascolecidae) from Mt. Phouleoi, Lao PDR: Earthworm specimens were collected on the top of Mt. Phouleoi, Viengthong District, Houaphanh province, Lao PDR. The new species belonged to pheretimoid earthworms. They have spermathecal pores in 7/8 and 8/9, corresponding to the aeruginosus-group as characterized by Sims and Easton (1972). Their names are: Amynthas bouatongi sp. nov., Amynthas hoauykanangensis sp. nov., Amynthas phimpheti sp. nov., Amynthas nametensis sp. nov., Amynthas somechanae sp. nov., Amynthas wiggeri sp. nov., Amynthas fleischmani sp. nov., Amynthas antethecus sp. nov., and Amynthas elenabondae sp. nov. With the exception of A. nametensis sp. nov., all have the first dorsal pore in an unusually anterior location close to 5/6 and very large, often coiled, prostatic ducts. Several species have slight intraparietal invaginations of the primary male pores, but the similarity of other characters leads us to include them in Amynthas rather than in a polyphyletic Metaphire. Amynthas bouatongi sp. nov. has male pores 0.20–0.24 circumference apart on reniform male pads, pair genital papillae medial and lateral to male pores in XVIII. Amynthas hoauykanangensis sp. nov. has openings of copulatory pouches 0.19–0.25 circumference apart, and paired round genital papillae on postsetal XVII and presetal XIX in line with the male pores. Amynthas phimpheti sp. nov. has male pores 0.21–0.24 circumference apart, round thickened genital papillae paired on 17/18 and 18/19 in line with male pores. Amynthas nametensis sp. nov. has male pores superficial on thickened circular pads, 0.24–0.27 circumference apart. Amynthas somechanae sp. nov. has male pores 0.20–0.33 circumference apart, and paired equatorial papillae in XVIII. Amynthas wiggeri sp. nov. has male pores 0.22–0.30 circumference apart, paired genital papillae equatorial on XVIII medial to male pores and paired papillae equatorial in XVII and XIX. Amynthas fleischmani sp. nov. has openings of copulatory pouches 0.24 circumference apart, paired conical genital papillae equatorial on XVII and XIX; paired circular papillae in intersegmental furrows of 17/18 and 18/19. Amynthas antethecus sp. nov. has openings of copulatory pouches 0.31 circumference apart, paired circular papillae in intersegmental furrow of 17/18 and equatorial on XIX, slightly medial to secondary male pores. Amynthas elenabondae sp. nov. has openings of copulatory pouches 0.19 circumference apart, crescent, convex medially; primary male pore on tubercle on lateral wall of shallow parietal invagination.

Two new earthworm species of the genus Amynthas (Oligochaeta: Megascolecidae) from central Taiwan, with comments on some recent species assignments in Amynthas and Metaphire

“…Nevertheless, what mentioned in the last part of the discussion section in James et al (2005), "Two newly discovered Amynthas from the Philippines...have a different and unique structure of the prostatic duct, which is modified to form a sheath over a small penis visible through the outer secondary male pores", is obviously in contradiction to Sims and Easton (1972) since secondary male pore is the opening of copulatory pouch, not to mention penis! Although James et al (2005), James (2009, 2013) and Hong et al (2018) cited Sims and Easton (1972) in their papers and compared their species with species listed in certain species groups classified by Sims and Easton (1972), they actually followed James et al's (2005) concept, which is more restricted than the one in Sims and Easton (1972). This is corroborated by the fact that among all the new earthworm species published by these authors from Korea to Laos during 2001-2018, no Metaphire species was reported.…”

“…The genital papilla arrangement in the male pore region of A. luridus is also similar to that of Amynthas oyamai (Ohfuchi, 1937) from northern Japan, Amynthas morii (Kobayashi, 1938) from Korea, Amynthas dangi (Thai, 1984) from Vietnam, and Amynthas nametensis Hong et al, 2018 from Laos. A. oyamai has a papilla antero-medial to each male porophore (Ohfuchi 1937); A. morii has a papilla anterior to each male porophore (Kobayashi 1938b); A. dangi has papillae widely paired in line with male porophore in presetal XVIII-XIX and a papilla medial to each male pore (Thai 1984;Nguyen et al 2016a); A. nametensis has papillae widely paired in line with male porophore in presetal XVIII-XIX (Hong et al 2018). Like A. luridus, A. oyamai and A. morii are also octothecal and have small or little developed seminal vesicles and small, short prostatic duct (Ohfuchi 1937;Kobayashi 1938a, b).…”

“…luridus, but A. nametensis is quadrithecal with two pairs of spermathecal pores in 7/8/9. Furthermore, A. nametensis has globular ampulla, diverticulum coiled into irregular ovate block, and prostate glands extending from XVII to XXIII with long, stout, coiled ducts (Hong et al 2018), whereas A. luridus has elongated oval-shaped ampulla, diverticulum with a slender stalk and a seminal chamber rudimentary or absent, and prostate glands in XVII-XIX with short, small, C-shaped prostatic ducts. Diagnosis.…”

“…However, Hong et al (2018), in their most recent descriptions of nine new Amynthas species from Laos, described "copulatory pouches" for the following species: Amynthas hoauykanangensis, Amynthas fleischmani, Amynthas antethecus and Amynthas elenabondae. Also, the term "secondary male pores" was mentioned for A. fleischmani, A. antethecus and A. elenabondae in the text, and the "transverse sphincter-like slit" of A. fleischmani, "opening surrounded by tubercular wrinkled epidermal ring" of A. antethecus and "crescent openings" of A. elenabondae described by the authors actually are openings of copulatory pouches (= secondary male pores).…”

Study on the Amynthas (Kinberg, 1867) earthworm (Megascolecidae: Oligochaeta) diversity through DNA barcoding from Northeast India

“…Due to proliferation of taxonomic descriptions of new species, distinctive morphological characteristics are not apparent at the species level and many cryptic species have been noted. For instance, recently a considerable number of redescription of earthworm species have been recorded for several taxa (Zhao et al, 2017;Azama and Ishizuka, 2018;Hong et al, 2018;Bozorgi et al, 2019;Csuzdi et al, 2019). Therefore, molecular intervention can serve as the only key to solve species validation (Blakemore, 2013).…”