Amynthas omodeoi Zhao and Qiu, 2009

Zhao, Qi, Sun, Jing & Qiu, Jiang-Ping, 2009, Three new species of the Amynthas hawayanus-group (Oligochaeta: Megascolecidae) from Hainan Island, China, Journal of Natural History 43 (17 - 18), pp. 1027-1041 : 1031-1038

publication ID	https://doi.org/ 10.1080/00222930902767433
persistent identifier	https://treatment.plazi.org/id/039EC87F-FFD8-FF81-FE17-FB54FC7CB354
treatment provided by	Felipe
scientific name	Amynthas omodeoi Zhao and Qiu
status	sp. nov.

Treatment

Amynthas omodeoi Zhao and Qiu sp. nov

( Figure 3 View Figure 3 )

Type material

Holotype: Clitellate specimen (C-HN006): 78 mm long, 2 mm wide, 123 segments. Setae numbers: 26/III, 26/ V, 36/XX, 36/XXV; 9( VI), 14( VII) between spermathecal, 8( XVIII) between male pores; collected in the brown soil under a dead and dying tree in Diaoluoshan National Forest Park , Southeast Hainan. (109 ° 519500 N, 18 ° 439450 E), at an altitude of 1008 m ( Figure 1 View Figure 1 ). Collected by Jiangping Qiu and Weixin Zhang.

Paratype: one clitellate (C-HN006): same data as for holotype.

Other material

Some data as for holotype, two aclitellate specimens.

Etymology

This species is named after Professor P. Omodeo, a famous oligochaetist who has contributed greatly to the taxonomy of earthworms.

Diagnosis

Spermathecal pores three pairs, ventral, in 5/6–7/8, about two-fifths of circumference apart. Male pores about one-third of circumference apart, ventrally placed, each on top of a round-headed porophore, surrounded by one to two indistinct wrinkles of skin. One pair of large oval papillae to the inner side of the male pores in 18/19.

Description

Worms non-pigmented ventrally. Olive brown dorsally. Brown on clitellum. Dimensions 78 mm by 2 mm, segments 123 (one specimen mutilated). Setae sparse, uniformly distributed, their numbers: 24–26 at III, 26–27 at V, 30–36 at XX, 34–36 at XXV; 7–9( VI), 14–15( VII) between spermathecae, 5–6( XVIII) between male pores; setal formula: AA51.8–2AB, ZZ51–1.3ZY. Female pore single in the centre of XIV ventrally, ovoid. First dorsal pore in 11/12. Prostomium one-half epilobous. Clitellum in XIV– XVI, markedly glandular, ring-shaped, smooth, setae and dorsal pore invisible .

Male pores about one-third of circumference apart, ventrally placed, each on top of a round-headed porophore in XVIII, surrounded by one or two indistinct wrinkles of skin. One pair of large oval papillae (diameter 0.6–0.8 mm) to the inner side of the male pores in 18/19. The distance is about one-quarter of the circumference apart. Spermathecal pores three pairs, ventral, in 5/6–7/8, about two-fifths of circumference apart.

Septa 8/9, 9/10 absent; 6/7, 7/8 comparatively thick; 10/11–12/13 a little thicker than those following. Gizzard long barrel-shaped, in IX–X. Intestine swelling in XVI. Intestinal caeca simple, originating in XXVII and extending anteriorly to XXIV, with a distinct ventral lobation, smooth dorsally. Hearts three pairs, in XI– XIII, conjoint with supraoesophageal vessel; the last the biggest. A pair of circular vessels in X, slender, conjoint with ventral vessel.

Spermathecae three pairs, in VI–VIII, ampulla ovoid, a little peaked at the top, duct thin, about two-thirds of ampulla, diverticulum about three-fifths of main pouch, ectal one-third straight, ental two-thirds twisted in zigzag fashion, forming seminal chamber. Testis sacs two pairs, in X, XI, the first is stouter. Seminal vesicles two pairs, in XI, XII, the first pair more developed. Prostate gland well developed, in XVII–XXIII, finger-shaped diverticulum, with a U-shaped duct, its ectal limb stouter. Accessory glands in XVIII–XIX, well developed, about 0.1–0.3 mm long, lobed, with a long restiform duct.

Remarks

This new species closely resembles Amynthas oculatus ( Chen 1938) in the characteristics of the male pores, genital papillae and septa. Both also have simple intestinal caeca and well-developed prostate gland and accessory glands. Furthermore, the diverticulum is in the same zigzag fashion. However, they are easily separated on the basis of spermathecal pores. Amynthas omodeoi sp. nov. has three pairs in 5/6–7/8, but A. oculatus has two pairs in 5/6–6/7. Moreover, the first pair of seminal vesicles is not enclosed in the second pair of testis sacs in A. omodeoi sp. nov. and A. omodeoi sp. nov., whose body length is 78 mm, is more than twice the size of A. oculatus . Finally, the position of the first dorsal pore is different. In A. omodeoi sp. nov. it is in 11/12, while in A. oculatus it is in 12/13.

This new species differs greatly from A. brevicingulus , A. limpidus and A. muticus because of the characteristics in the male pore region. It differs from Amynthas sinuosus by having three spermathecal pores. Comparisons with Amynthas species with spermathecal pores in 5/6–7/8 from China are shown in Table 1.