Amynthas shanghangensis Sun & Qiu, 2018

Sun, Jing, Jiang, Ji-Bao, Bartlam, Scott, Qiu, Jiang-Ping & Hu, Feng, 2018, Four new Amynthas and Metaphire earthworm species from nine provinces in southern China, Zootaxa 4496 (1), pp. 287-301 : 291-292

Amynthas shanghangensis Sun & Qiu , sp. nov.

( Figure 3 )

Type material. Holotype: One clitellate (C-GX201601-05), China, Guangxi Province, Maoershan National Natural Reserve (25°51'25"N, 110°29'36"E), 813 m asl, topsoil below arbor, shrub and fern in Mid-subtropical evergreen broad-leaved forest, yellow soil, 4 Jun. 2016, J. Sun, Y. Zheng and X. Gong coll. Paratypes: A total of 18 specimens, as follows: Four clitellates (C-GX 201210 -02) , China, Guangxi Province, Huaping National Natural Reserve (25°35'50"N, 109°56'06"E), 1536 m asl, topsoil below arbor and shrubs in Mid-subtropical evergreen broad-leaved forest, yellow soil, 12 Jun. 2012, J. B. Jiang, X. Sun and C. Zhao coll. Two clitellates (C-GX201321- 07) , China, Guangxi Province, Jiuwanshan National Natural Reserve (25°11'57"N, 108°47'44"E), 404 m asl, in Mid-subtropical evergreen broad-leaved forest, sandy yellow soil, 18 May 2013, J. P. Qiu, J. B. Jiang, L. L. Zhang and Y. Dong coll. Two clitellates (C-HU201308-04) , China, Hunan Province, Bamianshan National Natural Reserve (26°00'28"N, 113°53'12"E), 793 m asl, in Mid-subtropical evergreen broad-leaved forest, yellow soil, 22 Jun. 2013, J. B. Jiang, L. L. Zhang, Y. Dong and S. Lei coll. One clitellate (C-GX201602-07) , China, Guangxi Province, Maoershan National Natural Reserve (25°49'57"N, 110°27'43"E), 531 m asl, topsoil below arbor, shrub, fern and bamboo in Mid-subtropical evergreen broad-leaved forest, yellow soil, 4 Jun. 2016, J. Sun, Y. Zheng and X. Gong coll. One clitellate (C-FJ 201110 -02) specimen , China, Fujian Province, Meihuashan National Natural Reserve (25°20'15"N, 116°51'01"E), 1205 m asl, topsoil below fern in subtropical evergreen broad-leaved forest, sandy yellow-red soil, 13 Jul. 2011, J. B. Jiang, J. Sun, H. W. Feng and X. D. Lei coll. Six clitellates (C-GZ201614- 02) , China, Guizhou Province, Leigongshan National Natural Reserve (26°20'60"N, 108°16'50"E), 957 m asl, topsoil below fern, pine, and cotonier in Mid-subtropical evergreen broad-leaved forest, yellow soil, 2 Jun. 2016, J. Sun, Y. Zheng and X. Gong coll. One clitellate (C-HU201611-01) , China, Hunan, Shunhuangshan National Natural Reserve (26°24'00"N, 111°00'11"E), 771 m asl, abandoned paddy field of yellow soil, 4 May 2016, J. Sun, J. B. Jiang, Y. Dong and Y. Zheng coll. One clitellate (C-HU201608-10) , China, Hunan, Shunhuangshan National Natural Reserve (26°23'35"N, 111°03'52"E), 333 m asl, topsoil below moss, fern, and shrubs in Mid-subtropical evergreen broad-leaved forest, yellow soil, 4 May 2016, J. Sun, J. B. Jiang, Y. Dong and Y. Zheng coll.

Etymology. The name shanghangensis is given to this species with respect to the first specimen of this species, which was collected in Shanghang county, Fujian Province, China.

Diagnosis. Large-sized species; spermathecal pores four pairs in 5/6–8/9; male porophores surrounded by three papillae; genital papillae present in male pore region but not in spermathecal pore region; each prostate gland well-developed and accompanied by an accessory gland; spermathecal diverticulum about as long as main spermathecal axis, and distal half to third dilated into rod-shaped seminal chamber.

Description. External characters. Preserved specimens dark brown on dorsum, lacking pigment on ventrum, and whitish around segmental equator. Mid-dorsal line pigmented posterior to clitellum. Dimensions 210–241 mm by 6–8 mm at clitellum, segments number 104–111. Secondary annulations conspicuous in segments V–VIII. Prostomium ½ epilobous. First dorsal pore in 11/12, 12/13, or 13/14. Clitellum annular in XIV–XVI, smooth, swollen, no setae on ventral side of XVI, dorsal pores absent on clitellum. Setae uniformly distributed, thick and long in III–IX, 18–26 at III, 26–32 at V, 36–45 at VIII, 52–60 at XX, 54–64 at XXV; 8– 9/VI, 8– 10/VII, 10–14/VIII between spermathecal pores, 15–18 between male pores, setal formula AA=1.1–1.2AB, ZZ=1.2–1.5ZY. Spermathecal pores four pairs, in 5/6–8/9, intersegmental, about 0.4 of circumference ventrally apart; conspicuous, with a tubercle-like skin extension to anterior of intersegmental furrow ( Fig. 3A ). No genital papillae in this region in holotype specimen, but a small round papilla present at posterior of seta D on one side (right) only on VIII in paratype C-GX201602-07. Male pores in XVIII, 0.4 of circumference ventrally apart, each one glandular and a little depressed with a flat top, surrounded by a skin fold, and three papillae always surround the male pores, one in close proximity and lateral to the pore, one in close proximity and posterior to the pore, and one anterior and medial to the pore, the male porophores raised slightly ( Fig. 3 B ). No other male pore papillae present in holotype, but one or two transversely placed, small, flat-topped papilla anterior to setae AA in XVIII always present in paratypes. Female pore is single, mid-ventral in XIV, milk-white, elliptical, a little swollen.

Internal characters. Septa 8/9–9/10 absent, 4/5–6/7 and 10/11–12/13 thickened and muscular, 13/14–15/16 thicker than those following. Dorsal blood vessel single, continuous onto pharynx; esophageal hearts four pairs in X–XIII, the first pair less developed than the others. Gizzard bucket-shaped, in VIII–X; intestine swelling in XVI; intestinal caeca simple, originating in XXVII and extending forward to XXII, finger-shaped sac, smooth on dorsal and ventral margins. Male organs: Testis-sacs in X and XI; both pairs oval and separated ventro-medially. Seminal vesicles in XI, XII, more developed, both ventro-medially connected with a tube. Prostate glands well-developed, coarsely lobate, in XVI–XX, its duct inverted U-shaped, small, in XVIII ( Fig. 3C ). One accessory gland medial to each prostate gland duct, sessile, closely attached to the body wall on XVIII. Female organs: Spermathecae four pairs in VI–IX, about 3 mm long; ampulla heart-shaped and distinctly marked off from its duct, duct as long as ampulla; diverticulum about as long as main spermathecal axis, slender, distal ½–¼ dilated into rod-shaped seminal chamber; no nephridia on spermathecal ducts ( Fig. 3D ).

DNA barcodes. GenBank accession numbers KF205429 (C-FJ 201110 -02, holotype), KY774376 (C- GX201602-07, paratype), KY774377 (C-GX201601-05, paratype), KY774378 (C-GZ201614-02, paratype).

Remarks. Amynthas shanghangensis sp. nov. was collected from four provinces (Fujian, Hunan, Guangxi, and Guizhou) in nine locations. It keys to the Amynthas corticis group ( Sims & Easton 1972). The new species looks somewhat like the widely distributed species Amynthas carnosus ( Goto & Hatai, 1899) in the following characteristics: (1) dimensions; (2) dark-brown pigment on dorsum, lightly pigmented on ventrum, and near white around segmental equators; (3) first dorsal pore variable in 11/12 or 12/13; (4) spermathecal pores four pairs in 5/ 6–8/9; (5) intestinal caeca simple; (6) prostate gland well-developed; (7) accessory glands present in prostate glands region; (8) diverticulum seminal chamber elongated or rod-shaped ( Blakemore 2009; Chang et al. 2009). However, the new species has no genital markings in the spermathecal pore region, whereas A. carnosus has one or two papillae near each spermathecal pore. Secondly, the male porophore is surrounded by three papillae in the new species, but two papillae in different positions in A. carnosus . Thirdly, there are no accessory glands in the spermathecal pore region in the new species, but sessile or stalked accessory glands are present, corresponding to external genital papillae, in A. carnosus .

Superficially the new species resembles Amynthas cruxus Tsai & Shen, 2007 , which was initially collected from Taiwan Island ( Tsai et al. 2007). A. cruxus has four pairs of spermathecal pores in 5/6–8/9, a pair of slightly depressed male porophores, each surrounded by several papillae, a pair of simple intestinal caeca and welldeveloped prostate glands. However, A. cruxus can clearly be distinguished by the following: (1) adults of the new species are significantly larger than A. cruxus ; (2) the pigment of the new species is darker than that of A. cruxus ; (3) three papillae surround the male porophore in the new species, but four papillae surround the male porophore in A. cruxus ; (4) the diverticulum seminal chamber in the new species is rod-like, but round or oval in A. cruxus .

The new species is also similar to the South Korean species Amynthas youngtai Hong & James, 2001 . A. youngtai has similar dimensions, dark-brown dorsal pigment, four pairs of spermathecal pores, simple intestinal caeca, sessile accessory glands in their prostate glands, and rod- or club-shaped diverticulum seminal chamber ( Hong & James 2001). However, the new species differs from A. youngtai in several characteristics: (1) Genital markings are rarely present in the spermathecal pore region, with only an occasional single marking on VIII in the new species; on A. youngtai genital markings are paired in IX, with one genital marking occasionally absent. (2) Three genital papillae surround each male pore in the new species, but only one posterior genital papilla is associated with each male pore in A. youngtai . (3) The prostate glands are well developed in the new species, but much less developed in A. youngtai . Lastly, the diverticulum is about as long as the main spermathecal axis in the new species, but it is shorter than the main axis in A. youngtai .

Figures

FIGURE 3. Amynthas shanghangensis sp. nov. A. Spermathecal pores (sp). B. Male pores (mp) and genital papillae (gp). C. Prostate gland. D. Spermatheca.