Polypheretima cordata, Nguyen, Tung T., Tran, Binh T. T. & Nguyen, Anh D., 2015

Nguyen, Tung T., Tran, Binh T. T. & Nguyen, Anh D., 2015, Three new earthworm species of the genus Polypheretima Michaelsen, 1934 (Oligochaeta: Megascolecidae) from Vietnam, Zootaxa 3905 (4), pp. 593-600 : 597-599

Polypheretima cordata sp. nov.

( Fig. 3 , Table 2 )

Examined material. Holotype: 1C (CTU. EW042–h01) natural forest (11º06' 89.5N; 107º03' 10.3E), about 100 m asl, Ma Da commune, Vinh Cuu District, Dong Nai Province, 13/10/2013; coll. Duong Chi Trong. Paratypes: 5C (CTU. EW042–p01) and 2C ( HNUE –B242. CT1. Par.), same data as for holotype.

Further material. 4C (CTU. EW042–k01) natural forest (11º25' 42.0N; 107º25' 38.1E), 122 m asl, Cat Tien National Park, Tan Phu District, Dong Nai Province, Vietnam, 13/10/2013, coll. Le Van Nhan.

Diagnosis. Male pores located inside copulatory pouches; copulatory pores O-shaped. Genital markings absent in spermathecal and male regions. Three pairs of spermathecal pores, lateroventral in intersegments 5/6/7: one in 5/ 6 and two in 6/7; one spermatheca per pore. Ampulla characteristically heart-shaped; ducts as long as ampulla. Diverticula shorter than ampulla, more or less waved in the middle, attached to ampulla at base.

Etymology. The new species is named after the specific shape of the ampulla.

Description. External characters: Medium size, body cylindrical, length 98–168 mm, diameter 3.17–3.99 mm, weight 0.76–1.63 gr, 110–154 segments. Body uniformly whitish-brown. Clitellum darkish-brown. Prostomium prolobous. First dorsal pore in 12/13. Setae perichaetine, regularly arranged around segment, 61–90 in viii, 60–84 in xxx, 7–9 between porophores in xviii; setae distance aa=ab, zz=zy. Clitellum annular, xiv–3/4xvi, without setae and dorsal pores. Female pore single, mid-ventral in xiv. Three pairs of spermathecal pores lateroventral in intersegments 5/6/7: one pair in 5/6 and two in 6/7. Male porophores elevated; male pores located inside copulatory pouches in xviii; copulatory pores O-shaped. Ventral distance between male porophores about 0.3x body circumference. Genital markings absent in spermathecal and male regions.

Internal characters: Septa 4/5/6/7 thickened, 8/9/10 absent, 10/11/12 thinned. Oesophageal gizzard within viii–x. Intestinal origin at xv; caeca absent. Last hearts in xiii. Pharyngeal micronephridia well developed on septa 4/5/6. Lymph glands absent. A pair of spermathecae in 5/6 and two pairs of spermathecae in 6/7, one spermatheca per pore. Ampulla characteristically heart-shaped; ducts as long as ampulla. Diverticula shorter than ampulla, more or less waved in the middle, attached to ampulla at base. Two accessory glands before spermathecae in 5/6/7. Typhlosole lamelliform, but poorly developed. Holandric. Testis sacs separated. Seminal vesicles well developed in xi–xii. Oviduct well developed in 12/13. A pair of ovaries developed in xiii. Prostatic glands racemose in xvii–xix, rarely extending to xx; prostatic ducts small, slightly getting bigger distally. Accessory glands absent.

Remarks. Polypheretima cordata sp. nov. belongs to the Po. polytheca species-group Easton, 1979 characterized by multiple spermathecae per pore or per segment, but differs from other members in having three pairs of spermathecal pores in intersegments 5/6/7 (one in 5/6 and two in 6/7), and copulatory pouches. The species is similar to Po. grandisetosa ( Thai, 1996) in the following characters: prostomium prolobous; genital markings absent in spermathecal and male regions; spermathecal pores in 5/6/7; last hearts in xiii; septa 8/9/10 absent; diverticula shorter than ampulla in length; a pair of ovaries in xiii. However, Po. grandisetosa differs from the new species in being metandric, lacks of copulatory pouches, spermathecal pores two pairs in 5/6/7 and having 4-5 macrosetae dorsally on vi.

Locality and habitats. The species was found a depths of 5–10 cm under the soil surface in closed evergreen forests in Vinh Cuu Natural Reserve and Cat Tien National Park. Material was collected in October during dry season in southern Vietnam.

Figures

FIGURE 3. Polypheretima cordata sp. nov., paratype. A-B. Male pore region, ventral view (A), lateral view (B) (mp = male pore). C. Spermathecal region, lateral view (sp = spermathecal pore). D. Spermathecae in left pore in 5 / 6 / 7 (amp = ampulla, dv = diverticula, ag = accessory glands). E. Prostate gland. F. Copulatory pouch, transverse body section. Scales = 1 mm.