Amynthas majia, Wang & Shih, 2017

Wang, Yu-Hsi & Shih, Hsi-Te, 2017, Figs. 17 - 21. 17 - 20 in Taxonomic Review of Zavreliella Kieffer from East Asia, Zoological Studies 56 (18), pp. 1-12 : 8-11

Amynthas majia n. sp.

( Fig. 4 )

urn:lsid:zoobank.org:act:831BFDE1-BD35-450A-A14A-0DF7CEB891D9

Material examined: Holotype: 1 clitellate (NCHUZOOL 14492), Liangshan Waterfall , Majia, Pingtung, Taiwan, 22°40'58.1"N, 120°38'38.7"E, 95 m, 18 August 2010, collected by Y.-H. Wang et al . Paratypes: 2 clitellates and 2 aclitellates (NCHUZOOL 13548) same collection data as for holotype.

Etymology: This species is named for it type locality, Maja, a village inhabited by the aboriginal Paiwan Tribe in southern Taiwan. The name is used as a noun in apposition.

Diagnosis: Size 180.7-186.1 mm. Segments 103-124. Setae regularly distributed around segmental equators; 22 setae between male pores. Prostomium, epolibic. First dorsal pore at 12/13. Clitellum annular, xiv-xvi, with setae ventrally on xiv, xvi. Female pore single on xiv. Male pores on xviii with wrinkled edges, with large V-shaped genital marking close to male pore. Spermathecal pores 3 pairs laterally at 6/7-8/9, pore eye-shaped, without genital markings. Spermathecae three pairs in vii-ix. Seminal vesicles large in xi and xii. Prostates large in xvii-xviii, ducts thick, muscular; without copulatory pouch.

Description: External: Dimensions 180.7- 186.1 mm by 5.0- 5.2 mm in x, 5.7-5.9 mm in xxx, 5.3-5.5 mm in clitellum; body cylindrical throughout, segments 103-124. Setae regularly distributed around segmental equators; 22 setae between male pores; setal formula AA: AB: YZ: YZ = 1.6: 1: 1: 1.6 on xxv. Prostomium, epilobic. First dorsal pore at 12/13. Clitellum annular, xiv-xvi, with setae ventrally on xiv, xvi. Female pore single on xiv, 1 paratype with a pair of female pores. Male pores on xviii ( Fig. 4A ).

Male pores enlarged, with wrinkled edges, with large V-shaped genital marking close to male pore ( Fig. 4A ). Three pairs of spermathecal pores laterally at 6/7-8/9, pore eye-shaped, without genital markings, each pore with a slightly swollen edge between segments ( Fig. 4A ).

Septa, 5/6-7/8 thin, 8/9/10 absent, 10/11 thin, 11/12/13 thick, 13/14-15/16 thin; gizzard in x. Intestinal origin from xv; lymph glands in xxvixxix; typhlosole simple from xxii, extending forward as a small ridge to xv. Intestinal caeca with small incisions on ventral margin, originating in xxvii, extending anteriorly to xxii ( Fig. 4D ). Hearts in xi-xiii.

Male sexual system holandric, testes connected at ventral side, funnels ventrally joined to sacs in x and xi. Seminal vesicles large in xi and xii, with large dorsal lobe. Prostates in xviii, 4 main lobes, ducts thick, muscular; without copulatory pouch; joining vasa deferentia distal to glandular portion; vasa deferentia non-muscular ( Fig. 4C ).

Ovaries in xiii. Spermathecae paired in vii-ix, ampulla large, heart-shaped in vii-ix; diverticulum axis longer than ampulla axis, variously irregularly looped; with sessile accessory glands close to spermatheca in vi-viii, corresponding to each external swollen edge ( Fig. 4B ).

Ecology: The habitat was humid, covered with a thick layer of fallen leaves.

Remarks: This species is similar to Amynthas binoculatus , A. fusing n. sp., and A. lioujia n. sp., but with some different characters. Amynthas binoculatus and A. lioujia have large round genital markings on viii, A. binoculatus has 3 large genital markings with the male pore ( Tsai et al. 1999: fig. 4A), and A. lioujia has 2 large round genital markings closely adjacent to the male pore ( Fig. 3A ). Amynthas fusing has a large C-shape genital marking close to the male pore ( Fig. 2A ). Amynthas majia n. sp. has a large V-shaped genital marking close to the male pore and no genital markings on viii ( Fig. 4A ). A comparison of characters is given in table 1.

DNA analyses and discussion

A total of ten specimens of the four new species were used for molecular study. A 535-bp segment of COI was amplified, resulting in nine different haplotypes ( Table 2). The studied segment of the COI sequences was AT-rich (60.2%) ( T, 31.0%; A, 29.2%; G, 17.6%; C, 22.2%). According to the analysis of DNA barcoding, A. lalashan n. sp., A. micronarius ( Goto and Hatai, 1898) (from main islands of Japan) and A. mutabilitas Shen, 2012 (from Taiwan) form a monophyletic clade (NJ tree data not show), which A. lalashan and A. mutabilitas are as sister species. The pairwise nucleotide divergences for COI with K2P distance are shown in table 3. The mean interspecific K2P distance of A. lalashan is 14.6% with the closest A. mutabilitas , which is 4.7 times greater than the mean intraspecific distance of A. lalashan , 3.1% ( Table 3). In addition, the lowest interspecific K2P distance of A. lalashan is 13.7% with A. mutabilitas and the largest intraspecific distance of A. lalashan is 0.0%. From table 3, A. lalashan is close to A. micronarius and A. mutabilitas , but morphological characters (including number and position of spermathecal pores) are different. Amynthas micronarius has 4 pairs spermathecal pores at 5/6- 8/9 and 2 pairs of genital markings between 17/18 and 18/19 segments ( Goto and Hatai 1898: 74), but which is small-sized earthworm and distributed in Miyagi, main islands of Japan. Amynthas mutabilitas has 2 pairs spermathecal pores at 5/6/7 and the genital markings are variation close around to male pore and found in Taitung from Taiwan ( Shen 2012: fig. 2A-E). Amynthas lalashan has 4 pairs spermathecal pores at 5/6-8/9 and 2 pairs GMs on 18 and 19 segments ( Fig. 1A ) and is medium size worm which was collected in Taoyuan from Taiwan that was different to A. micronarius and A. mutabilitas .

The genetic analysis of DNA barcoding, A. binoculatus , A. fusing n. sp., A. lioujia n. sp. and A. majia n. sp. form a monophyletic clade (NJ tree data not show), with the front two as sister species. The mean interspecific K2P distance of A. binoculatus is 4.3% with the closest A. fusing , which is greater than the mean intraspecific distance of A. binoculatus , 0.0% ( Table 3). In addition, the lowest interspecific K2P distance of A. binoculatus is 4.1% with A. fusing , which is greater than the mean intraspecific distance of A. binoculatus , 0.0%. The mean interspecific genetic distance of other earthworm DNA barcoding studies were variations: 15.4% ( Huang et al. 2007); 18.7% ( Chang et al. 2009b); 19.8% ( James et al. 2010); 13.7% ( Jiang et al. 2015), which could support genetic distance of A. lalashan and A. mutabilitas . However, the mean interspecific genetic distance of Amynthas binoculatus and A. fusing is smaller than above values, but NJ tree (not show) and morphological characters are enough to support that are different species. In conclusion, morphological characters and COI sequences analysis support four species are different species.

Acknowledgments: This work and the new species name have been registered with ZooBank under urn:lsid:zoobank.org:pub:C60B3332-6686-47B0-BED3-29E30815C156 . This study was supported by a grant from the Ministry of Science and Technology ( MOST 105-2621-B-005-002- MY3), Executive Yuan, Taiwan to HTS. We wish to thank Guan-Cyun Guo, Yu-Ching Lai, Wei-Chin Li and Yu-Chia Chang for specimen collection in Taiwan.

Figures

Fig. 4. Amynthas majia n. sp. holotype, NCHUZOOL 13548: (A) ventral view of male pores with large V-shaped genital markings on xviii; (B) left spermathecae; (C) left prostate; (D) right intestinal caeca. ag, accessory gland; amp, ampulla; dv, diverticulum; fp, female pore; gm, genital marking; mp, male pore; sp, spermathecal pore. All scale bars = 1 mm.

Fig. 3. Amynthas lioujia n. sp. holotype, NCHUZOOL 13547: (A) ventral view of male pores with two large genital markings on xviii; (B) lateral views of left spermathecal pores from two specimens (left, NCHUZOOL 13547; right, NCHUZOOL 13547 (no. 4)); (C) right spermathecae and accessory glands; (D) right prostate; (E) right intestinal caeca. ag, accessory gland; amp, ampulla; dv, diverticulum; fp, female pore; gm, genital marking; mp, male pore; sp, spermathecal pore. All scale bars = 1 mm.

Fig. 2. Amynthas fusing n. sp. holotype, NCHUZOOL 13542: (A) ventral view of male pores with large C-shaped genital markings on xviii; (B) left lateral view of spermathecal pores at intersegmental furrows with genital markings; (C) right spermathecae and accessory glands; (D) right prostate; (E) right intestinal caeca with vasa. ag, accessory gland; amp, ampulla; dv, diverticulum; fp, female pore; gm, genital marking; mp, male pore; sp, spermathecal pore. All scale bars =1 mm.

Fig. 1. Amynthas lalashan n. sp. holotype, NCHUZOOL 13541: (A) ventral view of spermathecal pores at intersegmental furrows; male pores with genital markings presetal on xviii and xix; (B) right spermathecae; (C) right prostate and small accessory glands; (D) right intestinal caeca. ag, accessory gland; amp, ampulla; dv, diverticulum; fp, female pore; gm, genital marking; mp, male pore; sp, spermathecal pore. All scale bars = 1 mm.