Polypheretima cattienensis, 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 : 594-595

Polypheretima cattienensis sp. nov.

( Fig. 1 , Table 2 )

Examined material. Holotype: 1C (CTU-EW040-h01) natural forest (11º25' 30.9N; 107º25' 42.2E), 122 m asl, Cat Tien National Park, Tan Phu District, Dong Nai Province, Vietnam, 13/10/2013, coll. Le Van Nhan. Paratypes: 4C (CTU-EW040-p01) and 2C (HNUE-B240. CT1. Par.), same data as for holotype.

Diagnosis. Male pores deeply located inside copulatory pouches; copulatory pores crescentic. Genital markings absent in male and spermathecal regions. Spermathecae arranged in two pairs of pores in intersegments 5/6/7, seven spermathecae per porus. Ampulla slightly expanded distad; distal and basal parts of ampulla not clearly differentiated. Diverticula shorter than ampulla, attached to ampulla near base.

Etymology. Named after the Cat Tien National Park, a biosphere reserve in South Vietnam, where the type material was found.

Description. External characters: Body generally cylindrical, but slightly bigger in segments iv–vii. Large size, length 115–147 mm, diameter 6.41–8.63 mm, body weight 2.82–4.28 gr, 132–189 segments. Segments i-vii darkish green, other segments paler, rather uniformly colored. Prostomium epilobous (2/3). First dorsal pore in 12/ 13. A darkish blue line present mid-dorsally from post-clitellum to the end. Setae perichaetine, never excessively crowded ventrally, regularly arranged around each segment, 90–114 in viii, 95–129 in xxx, 3–8 between male porophores in xviii; setae distance aa=2ab, zz=2zy. Clitellum annular, xiv–xvi, smooth without setae and dorsal pores. Female pore single, mid-ventral in xiv. Spermathecal pores large, in two pairs, lateroventral in intersegments 5/6/7. Male porophores highly elevated; male pores located deeply inside copulatory pouches in xviii; copulatory pores crescentic. Ventral distance between male porophores about 0.25x body circumference. Genital markings absent in male and spermathecal regions.

Internal characters: Septa 4/5/6/7/8 thickened, 8/9/10 absent, 11/12/13 thinned. Oesophageal gizzard large, but short within ix–x. Intestinal origin at xv; caeca absent. Last hearts in xiii. Pharyngeal micronephridia poorly developed on septum 4/5, and more developed on septum 5/6. Lymph glands absent or poorly present only in xv–xx. Spermathecae arranged in two pairs of pores in 5/6/7; seven spermathecae per porus. Ampulla slightly expanded distally, distal and basal parts of ampulla not clearly differentiated. Diverticula shorter than ampulla, attached to ampulla near base. Accessory glands absent. Typhlosole simple, lamelliform. Holandric. Testis sacs not separated. Seminal vesicles well developed within xi–xii. Ovaries paired, poorly developed on septum 12/13. Oviduct on septum 12/13 ventrally. Prostate glands racemose, paired in xviii, two main branches extending from xvii–xix; prostatic ducts C-shaped, ending at elevated, large chambers in coelom. No accessory glands.

Remarks. The species belongs to the Po. polytheca species-group Easton, 1979 characterized by multiple spermathecae per pore, but differs from other members in having two pairs of pores in intersegments 5/6/7, seven spermathecae per pore, and copulatory pouches. The species is somewhat similar to Polypheretima parataprobanae ( Thai & Nguyen, 1993 in Nguyen 1993) in the morphology of the male region, first dorsal pore in 12/13 and in the presence of a copulatory pouch. However, Po. parataprobanae differs from the new species in smaller body size (length 60–71 mm, diameter 4.5–6 mm), spermathecal pores paired lateroventrally in only 7/8, genital. The new species is also similar to Po. aringeana (Beddard, 1990) from Malaya in first dorsal pore in 12/13, spermathecal pores paired in 5/6/7, and multiple spermathecae per porus. Po. aringanea differs from the new species in the presence of genital markings in both male and spermathecal regions, 7–10 spermathecae per porus in vi and vii, and shallow copulatory pouches.

Locality and habitat. Cat Tien National Park is located in Dong Nai province, about 170km north-east from Ho Chi Minh City. It is known as a biosphere reserve and the best conserved forest in Vietnam, with high diversity of animals, plants, and habitats. The species was found a depths of 5–10 cm under the soil surface in closed evergreen forests. Material was collected in October during dry season in southern Vietnam.

Figures

FIGURE 1. Polypheretima cattienensis 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 (amp = ampulla, dv = diverticula). E. Prostate gland. F. Copulatory pouch, transverse body section. Scales = 1 mm.