Amynthas tertiadamae
Creators: name: Nguyen, Tung T.
name: Trinh, Kim-Binh T.
name: Nguyen, Hong-Lan T.
name: Nguyen, Anh D.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Clitellata
Opisthopora
Megascolecidae
Amynthas
Amynthas tertiadamae

description: <i>Amynthas tertiadamae</i> (Michaelsen, 1934) (Figure 6) <i>Pheretima tertiadamae</i> Michaelsen, 1934: 535, figs XXIII–XXV. <i>Amynthas tertiadamae –</i> Sims &amp; Easton 1972: 235, 246. <i>Material examined</i> 40 matures (CTU-EW 095.01) An Son Island (09°41 <i>ʹ</i> 11.1 <i>ʹʹ</i> N, 104°21 <i>ʹ</i> 10.8 <i>ʹʹ</i> E), Kien Hai District, Kien Giang Province, 17 November 2013, coll. Kim-Binh T. Trinh; 39 matures (CTU-EW 095.02) same locality, but 13 October 2014. <i>Diagnosis</i> Small size, length 68–92 mm, diameter 2.2–3.0 mm, 87–122 segments. Prostomium 1/2 epilobous. First dorsal pore in 12/13. Setal number 32–47 in viii, 43–53 in xxx, 6–10 between male porophores in xviii; setal distance aa&gt; ab, zz&gt; zy. Four pairs of spermathecal pores in lateroventral intersegments 5/6/7/8/9. Male pores located in xviii, without copulatory pouches. Genital marking absent in the spermathecal region, but two pairs in 17/18 and 18/ 19 in front of and behind the male pores, respectively. Testis sacs separated. Holandric. Intestinal caeca simple, xxvii–xxiv. Septa 8/9/10 absent. <i>Re-description</i> <i>External characters.</i> Body cylindrical, small size; length 68–92 mm, diameter 2.2– 3.0 mm, weight 0.29–0.54 g; 87–122 segments. Dorsum darkish brown, but ventrum paler. Prostomium 1/2 epilobous (open) First dorsal pore in 12/13. Setae perichaetine, short; pre-clitellar setae stouter and sparser than post-clitellar setae, 32–47 in viii, 43–53 in xxx, 6–10 between male porophores in xviii; setal distance aa&gt; ab, zz&gt; zy. Clitellum annular, xiv–xvi, greyish brown, smooth and without setae and dorsal pores. Female pore single, mid-ventral in xiv. Spermathecal pores four pairs, in lateroventral intersegments 5/6/7/8/9. Genital markings absent in the spermathecal region. Male pores directly opened in xviii, without copulatory pouches; ventral distance between male porophores about 0.4× body circumference. Porophores slightly elevated from body wall. Two pairs of small, bean-shaped genital markings in front of and behind porophores in xviii. <i>Internal characters.</i> Septa 5/6/7/8 thickened, 8/9/10 absent, 10/11/12/13 thin. Oesophageal gizzard after viii. Intestinal origin at xv; caeca simple, within xxvii–xxiv, enlarged basally. Last hearts in xiii. Pharyngeal micronephridia poorly developed in 5/6/ 7. Lymph glands from 16/17, small, lobuled. Typhlosole simple, lamelliform (segments 24–41). Spemathecae paired in vi–ix. Spermathecal ampulla large, egg-shaped, whitish yellow; duct stout, about one-quarter ampulla length. Diverticula directly attached to base of ampulla duct, strongly coiled and folded, shorter than ampulla; distal part enlarged to be a seminal chamber. No accessory glands. Holandric. Testis sacs separated in x, xi. Seminal vesicles well developed within xi–xii. Ovaries invisible; oviduct after septum 12/13. Prostate glands deeply lobuled, paired in xvi–xxi; prostatic ducts U-shaped, slightly bigger distally. Accessory glands invisible. <i>Habitats</i> All specimens were found in clay soils in natural forest and plantation. <i>Remarks</i> New material was collected in An Son Island, about 60 km southeastward from the type locality, Phu Quoc Island. New material totally agrees with Michaelsen (1934) ’s description. The species is fairly close to <i>Amynthas juliani</i> (Perrier 1875) by having first dorsal pore in 12/13, four pairs of spermathecal pores in intersegments 5/6/7/8/9, no copulatory pouches, simple intestinal caeca, deeply lobuled prostatic glands and genital markings in male region. However, <i>A. juliani</i> has larger size (260–389 mm in length) and more segments (126–260 segments), prolobous prostomium, three pairs of genital markings on setal rings of xvii, xix and xx, thickened septa 8/9, mushroom-shaped spermathecal ampulla, and diverticula being not coiled (Perrier 1875).
description: Published as part of <i>Nguyen, Tung T., Trinh, Kim-Binh T., Nguyen, Hong-Lan T. &amp; Nguyen, Anh D., 2017, Earthworms (Annelida: Oligochaeta) from islands of Kien Hai District, Kien Giang Province, Vietnam, with descriptions of two new species and one subspecies, pp. 883-915 in Journal of Natural History 51 (15 - 16)</i> on pages 890-892, DOI: 10.1080/00222933.2017.1294213, http://zenodo.org/record/5180885
description: {"references": ["Michaelsen W. 1934. Oligochaten von Franzosisch-Indochina. Archive de Zoologie Experimentale et Generale. 76: 493 - 546.", "Sims RW, Easton EG. 1972. A numerical revision of the earthworm genus Pheretima auct. (Megascolecidae: Oligochaeta) with the recognition of new genera and an appendix on the earthworms collected by the Royal Society North Borneo Expedition. Biol J Linnean Soc. 4: 169 - 268.", "Perrier E. 1875. Sur les vers de terre desiles de Philippines et de la Cochinchine. Les Comptes Rendus de l' Academie des Sciences. 81: 1043 - 1046."]}