Amynthas qiongzhongensis Jiang and Zhao, 2014

Jiang, Jibao, Sun, Jing, Zhao, Qi & Qiu, Jiangping, 2014, Four new earthworm species of the genus Amynthas Kinberg (Oligochaeta: Megascolecidae) from the island of Hainan and Guangdong Province, China, Journal of Natural History 49 (1), pp. 1-17 : 13-16

Amynthas qiongzhongensis Jiang and Zhao sp. nov.

( Figure 4)

Material

Holotype. 1 clitellate (C-HN022-02A): China, Hainan Island, Diaoluoshan National Nature Reserve (18°43 ′ 30 ″ N, 109°52 ′ 07 ″ E), 920 m elevation, brown sandy soil under shrubbery, 6 July 2006, J.P. Qiu, M.B. Bouché, J.X. Li and X.L. Zhang colls.

Paratypes. 9 clitellates (C-HN022-02B) with the same data as for holotype. 2 clitellates (C-HN201008-01), 2 clitellates (C-HN201008-02): China, Hainan Island, Diaoluoshan National Nature Reserve (18°43 ′ 35 ″ N, 109°52 ′ 02 ″ E), 934 m elevation, black soil under palm trees, 24 July 2010, J.B. Jiang and Y.Z. Guo coll. 1 clitellate (C-HN201012-02): China, Hainan Island, Diaoluoshan National Nature Reserve (18°43 ′ 15 ″ N, 109°52 ′ 18 ″ E), 933 m elevation, black soil under scrubs, 24 July 2010, J.B. Jiang and Y.Z. Guo coll. 1 clitellate (C-HN201114-02): China, Hainan Island, Limushan Nature Reserve, Quling Mountain (19°13 ′ 40 ″ N, 109°44 ′ 15 ″ E), 739 m elevation, 27 May 2011, J.P. Qiu, J.B. Jiang, Q. Zhao, D. Cluzeau and W.K. Zhang coll.

Six individuals were dissected and 10 individuals were characterized externally only.

Etymology

The species is named after its type locality ( Li-Miao Autonomous County of Qiongzhong , Hainan) .

Diagnosis

Dimensions 81 – 161 mm by 3.4 – 4.6 mm at clitellum, segments 127 – 159. Setae numbering 42 – 46 at III, 48 – 64 at V, 50 – 62 at VIII, 40 – 54 at XX, 40 – 80 at XXV; 4 – 8 between male pores; 21 – 26 between spermathecal pores. Spermathecal pores in 5/6 – 6/7, 0.40 body circumference ventrally apart. Male pores in XVIII, 0.33 body circumference ventrally apart, each on the top of a slightly raised, oval porophore in a pulvinate pad with three to five circular folds. Spermathecae two pairs in VI – VII, ampulla heart-shaped, duct slightly shorter than ampulla. Diverticulum is longer than the main pouch by one-fifth, terminal two-sevenths dilated into a swollen chamber.

External characters

Grey dorsal pigment present in the pre-clitellum segments of preserved specimens; light brown pigment on dorsum of the post-clitellum segments; no pigment on ventrum. Dimensions 81 – 161 mm by 3.4 – 4.6 mm at clitellum, segments 127 – 159; the average values of examined individuals: dimensions 125 mm by 3.9 mm at clitellum, segments 147. Secondary annulations conspicuous in pre-clitellum segments. Prostomium combined prolobous and ½ epilobous. First dorsal pore in 11/ 12. Setae numbering 42 – 46 at III, 48 – 64 at V, 50 – 62 at VIII, 40 – 54 at XX, 40 – 80 at XXV; 4 – 8 between male pores; 21 – 26 between spermathecal pores; setal formula: AA = 1.0 – 1.5AB, ZZ = 1.0 – 2.0ZY. Clitellum annular, purple or light brown colour, in XIV – XVI, setae invisible externally.

Spermathecal pores two pairs in 5/6 – 6/7, ventral, 0.40 circumference apart from each other. A couple of antrorse genital papillae surround each spermathecal pore. A pair of tiny, collapse-topped, presetal genital papillae present on anterior border of segments VII.

Male pores one pair in XVIII, 0.33 circumference ventrally apart from each other, each on the top of a slightly raised, oval porophore in a pulvinate pad with three to five circular folds. Four or five genital papillae tiny, collapse-topped, surrounding each male pore, present on the porophore ( Figure 4A).

Female pore single in XIV, rounded, milky white.

Internal characters

Septa 5/6 – 7/8 thick and muscular, 10/11 – 12/13 slightly thickened, 8/9 – 9/10 absent. Gizzard short bucket-shaped, in 1/2VIII – IX. Intestine enlarged distinctly from XVI. Intestinal caeca paired in XXVII, simple, smooth, extending anteriorly to XXIV. Oesophageal hearts in X – XIII.

Ovaries in XIII. Spermathecae two pairs in VI – VII, ampulla heart-shaped, about 2.8 mm long in holotype; stout duct slightly shorter than ampulla. Diverticulum is longer than the main pouch by one-fifth, slender, terminal twosevenths dilated into a swollen chamber ( Figure 4B), milky white. No accessory glands observed.

Male sexual system holandric, testis sacs two pairs, in X – XI. Seminal vesicles two pairs, extending in XI – XII, the anterior pair well developed. Prostate glands well developed, inserting in XVIII and extending to 1/2XV and XXIII, coarsely lobate composed of several major lobes. Prostatic duct U-shaped, slender, conspicuously curved at the distal part ( Figure 4C). No accessory glands observed.

Remarks

The new species is similar to A. tripunctus in having similar body length, body width, prostate glands and ampulla shape, but it has a shorter seminal chamber, while the terminal half of the diverticulum of A. tripunctus is dilated into a cucumber-shaped chamber.

Amynthas qiongzhongensis sp. nov. differs greatly from A. incongruus by the characteristics of the accessory glands and spermathecae.

Amynthas qiongzhongensis sp. nov. differs from A. instabilis sp. nov. in the features of spermathecae, prostate glands and other characters.