Metapheretima tani ( Thai , 1996 )

Nguyen, Tung T., Tran, Binh T. T. & Nguyen, Anh D., 2014, Earthworms of the ' acaecate' Pheretima group in Vietnam (Oligochaeta: Megascolecidae), with description of a new species from the Mekong delta, Zootaxa 3866 (1), pp. 105-121 : 106-108

Metapheretima tani ( Thai, 1996) , comb. nov.

( Fig. 1 )

Pheretima tani Thai, 1996: 4 , Fig. 3 A.

Polypheretima tani — Nakamura 1999: 7; Blakemore 2007: 53.

Type material. Holotype: 1A (SORC-HV.227) Vietnam, Phu Yen province, Tuy Hoa city, Hoa Binh co-operative, 15 November 1989, coll. Nguyen Duc Tan. Paratype: 1A (SORC-HV.227) same date as holotype ( Thai 1996).

Description. Body cylindrical, unpigmented. Prostomium epilobous. First dorsal pore in 12/13. Setae numerous, regularly distributed on pre- and postclitellar segments, 104 in V, 110 in VIII, 104 in XIII, 66+ 18 in XVIII and 70 in XXV, aa=1.5ab, zz=zy. Numerous spermathecal pores in paired batteries in furrow 4/5. Crescentic genital markings associated with the porophores in XVIII. Genital markings paired, presetal on XIX–XXI, and presetal on VIII, IX and postsetal on VII, VIII. Spermathecae 15 pairs in 4/5. Ampulla somewhat enlarged distad, diverticula shorter. Holandric. Testes sacs ventral. Seminal vesicles developed in XI, less developed in XII. Ovisacs developing in XIII. Last hearts in XII. Intestine beginging at XV, and intestinal caeca absent. Typhlosole simple, lamelliform, T=0.21. Septa 8/9/10 absent, 5/6/7/8 thickened, 10/11/12 slightly thickened. Pharyngeal micronephridia in 7/8. (Data from Thai 1996: 4.)

Records from Vietnam. Phu Yen Province (Tuy Hoa).

Distribution. Only known from Vietnam.

Remarks. The species is fairly similar to Polypheretima elongata ( Perrier, 1872) , but it is polythecal (about 15 spermathecae in V), with external markings in front of the clitellum and two pairs of crescentic genital markings in the male region. The species was transferred to Polypheretima by Nakamura (1999) and Blakemore (2007), but with the presence of two pairs of crescentic genital markings in XVIII ( Thai 1996), the species fits better in Metapheretima . Blakemore (2007) considered it as " species inquirenda ", but did not give arguments. Types were rechecked for this study and the species diagnosis is confirmed here.

Metapheretima tiencanhensis (Pham, 1995) , comb. nov. ( Fig. 1 )

Pheretima tiencanhensis Pham, 1995b: 24 , Fig. 1 C. Polypheretima tiencanhensis — Nakamura 1999: 7.

Type material. Holotype: 1C (SORC-HV.228) Quang Nam province, Tien Phuoc, Tien Canh, village No.1, 27 January 1988, coll. Pham Thi Hong Ha; Paratype: 1C (SORC-PV.228.1) Quang Nam province, Tra My town, group No.3, garden, 4 March 1989, coll. Pham Thi Hong Ha (Pham 1995).

Description. Body length 197mm, diameter 6 mm, segments 190, weight 2.3 gr. Medium size, colour ash. Clitellum 1/2XIII-3/4XVI. Prostomium epilobous. First dorsal pore in 11/12. Setae numerous, regularly distributed on segments, 87(43) in IV, 110(44) in V, 126 in VIII, 118 in XIII, 87+ 23 in XVIII, 82 in XIX, aa>ab, zz>zy. Crescentic genital markings associated with male porophores. Two pairs of genital markings on XVII and XIX. Spermathecal pores paired in 4/5–6/7. A pair of genital markings round on VII. Ampulla subequal to ducts in length, diverticula shorter. Testes sacs ventral, not separated. Prostate glands in XVII–XIX, strongly lobuled. Last heart in XIII. Intestine beginning at XV, without coeca. Typhlosole lamelliform, T=0.24. Septa 8/9/10 absent. Pharyngeal micronephridia in 7/8. (Data from Pham 1995: 24.)

Records from Vietnam. Quang Nam Province (Tien Phuoc; Tra My).

Distribution. Only known from Vietnam.

Remarks. The species is particularly similar to Metapheretima vietnamensis Thai, 1984 , but differs in body size, position, number and morphology of spermathecal pores. The species was transferred to Polypheretima by Nakamura (1999) and Blakemore (2007), but with the presence of two pairs of crescentic genital markings in XVIII ( Thai 1996), the species fits better in Metapheretima . Blakemore (2007) considered it as " species inquirenda ", but did not give arguments. Types were rechecked for this study and the species diagnosis is confirmed here.

Figures

FIGURE 1. Distribution of species of the genus Metapheretima in Vietnam.

FIGURE 3. Distribution of species of the genus Polypheretima in Vietnam. The exotic Po. elongata with many records all over the country is omitted.