Drawida cheni, Zhang & Li & Qiu, 2006

Zhang, Wei-Xin, Li, Jian-Xiong & Qiu, Jiang-Ping, 2006, New earthworms belonging to the genus of Amynthas Kinberg (Megascolecidae: Oligochaeta) and Drawida Michaelsen (Moniligastridae: Oligochaeta) from Guangdong, China, Journal of Natural History 40 (7 - 8), pp. 395-401 : 399-401

Drawida cheni sp. nov.

( Figure 3 )

Type material

Holotype: a mature specimen (dissected) collected 24 June 2004 from the ravine rain forest (elevation 290 m) in Mt. Dinghu , Guangdong, China, coll. Weixin Zhang (coll. no. 2004- 007 GDDH) . Paratype: a mature specimen (coll. no. 2003-017 GDDH) collected 27

November 2003, and an immature specimen (coll. no. 2004-027 GDDH) collected 7 September 2004 (same collection site as for holotype) .

External characters

Body large, smooth, with yellowish pigment, slightly sharp at head end and blunt at the caudal part. Dimensions 110–185 mm by 9–11 mm at segment X, segments number 165–174. Annulets are conspicuous in IV–XXIX segments. Prostomium prolobous. Clitellum not observed. Dorsal pores absent, and setae are also invisible externally.

Spermathecal pore: one pair in 7/8 intersegmental furrow, ventral, 0.4 body circumference apart from each other, each on the centre of a longitudinally orientated, flat elliptical whitish glandular membrane patch. Genital markings not present.

Male pore: one pair in 10/11 intersegmental furrow, 0.4 body circumference ventrally apart from each other, slightly swollen, each on the centre of a large, longitudinally orientated, flat elliptical whitish glandular membrane patch. Genital papillae not present.

Female pore: one pair in 12/13, 0.4 body circumference ventrally apart from each other. Segment XII is distinctly short ( Figure 3A ).

Internal characters

Septa 5/6–8/9 greatly thickened, muscular. Gizzards five in XII–XXII segments (in XII– XIV, XV–XVI, XVII–XVIII, XIX–XX, and XXI–XXII, respectively), same size, shining on the surface with whitish vertical fibres. Intestine enlarged distinctly at segments XXIV– XXVI, just behind the last gizzard. Oesophageal hearts greatly thickened, black in VI–IX. Meganephridia present, beginning at least from VI, about 20–30 mm long, pairs in each segment close to the anterior septum. There are a few brownish black dots on the surface of segments anterior to VII.

Testis sac: one pair, about 6 mm long, 3.5 mm wide, yellowish, each suspended in middle part of septum 9/10. Ovarian chambers are in XI–XII, about 3.5 mm, vertical long pouchshaped or palm-like.

Spermathecae one pair in VIII, ampulla oval-shaped, yellowish, about 2.5 mm long, 1.2 mm wide, narrowly attached to the surface of septum 7/8 with a short connective tissue; from its lower side a duct arising, gradually narrowing and making a number of great coils from its median part, about 23 mm in total length, spermathecal atrium inconspicuous or absent (not certain). No accessory glands are present ( Figure 3B ).

Remarks

In appearance Drawida cheni sp. nov. is somewhat similar to Drawida sulcata Zhong, 1986 from Yunnan, China. They share similar characters of external appearance, large body size, absent dorsal pore, absent clitellum, oval-shaped testis sac and ampulla, and convoluted duct. However, the new species is distinguished from D. sulcata and other species by the five gizzards which otherwise can only be found in D. syringa Chen, 1933 , the absent genital papillae, inconspicuous thumb-shaped spermathecal atrium, as in Drawida nemorus Kobayashi, 1936 whose spermathecal duct also terminates without any trace of atrial dilatation. Furthermore, Drawida cheni sp. nov is characterised by the smooth body without setae, the intestine origin immediately behind the last gizzard, the female pore in 12/13, and the superficial male pore covered by a glandular membrane patch, with no atrium or penis present.

The name cheni is given after Prof. Chen Y., who made great contributions to the earthworm systematics of China.

Figures

Figure 3. External views (ventral) showing spermathecal pores, male pores and female pores (A) and spermathecae (B) of Drawida cheni sp. nov. fp, female pores; mp, male pores; sep, septum; sp, spermathecal pores.