Metaphire peguana peguana ( Rosa, 1890 )

Nguyen, Tung T., Lam, Dang H. & Nguyen, Anh D., 2023, A revision of the Metaphire peguana species-group (Oligochaeta: Megascolecidae) from Vietnam, Zootaxa 5255 (1), pp. 113-135 : 121-123

Metaphire peguana peguana ( Rosa, 1890)

( Figure 4 , Table 3 )

Perichaeta peguana Rosa 1890: 113 , figs. 6–8; Beddard 1895: 403.

Amynthas (Pheretima) peguanus – Michaelsen 1899: 7.

Pheretima peguana – Michaelsen 1900: 292; Gates 1939: 102, 1972: 207; Omodeo 1956: 325; Thai 1983: 124; Thai 1987: 7, 2000: 309; Thai & Do 1989: 77; Nguyen & Tran 2008: 185; Thai et al. 2004: 759; Huynh 2005: 88; Nguyen et al. 2010: 114, 2011: 1025; 2012: 146; Nguyen & Nguyen 2010: 123; Nguyen 2014: 109.

Amyntas peguanus Beddard 1900: 628 .

Pheretima peguanna (sic!) – Huynh & Nguyen 2004: 116.

Metaphire peguana – Sims & Easton 1972: 239; Easton 1981: 58; Blakemore 2002: 207, 2008: 78, 2016: 7; Shen & Yeo 2005: 14; Sarkar et al. 2012: 178; Nguyen et al. 2016: 63 ; 2020: 8 .

Metaphire peguana peguana – Nguyen et al. 2017a: 98, 2021a: 17, 2021c: 105; Lam et al. 2021: 17701.

Type locality. Myanmar (Rangoon) ( Rosa 1890)

Type material. Natural History Museum Giacomo Doria (44037), Italy .

Diagnosis. Body cylindrical, length 81–143 mm, diameter 3.7–6.3 mm, segments 60–157. Prostomium epilobous. First dorsal pore at 12/13 or 13/14. Three pairs of spermathecal pores in ventrolateral intersegments 6/7/8/9, bithecate. Two pairs of disc–shaped genital markings on intersegments 17/18 and 18/19, each with a small opening at the center. Male pores located inside copulatory pouches in xviii. Septum 10/11 only present ventrally. Intestinal caeca simple. Holandric, testis sacs separated. Accessory glands coelomic, strongly covered by muscularwalled bursae in 17/18 and 18/19.

Habitat. The species is found in leaf litter in various types of habitats in Southern Vietnam .

Distribution. French Guiana ( Csuzdi & Pavlíček 2010), India, Thailand ( Blakemore et al. 2006; Prasankok et al. 2013), Myanmar, Malaysia, Indonesia, Japan ( Gates 1972; Ishizuka 1999; Ng et al. 2017), Singapore ( Shen & Yeo 2005), Cambodia, Laos (Thai & Samphon 1989), Bangladesh (Sarkar et al. 2012), Australia ( Easton 1982), and commonly found in Vietnam ( Nguyen et al. 2016, 2021a, 2021c; Lam et al. 2021) ( Fig. 3 ).

Remarks. Metaphire peguana peguana is the typical form and the one found outside of Southeast Asia along with M. bahli . Although this subspecies has a relatively stable morphology with genital markings paired in 17/18 and 18/19, there was still a slight difference throughout populations in Vietnam. Vietnamese specimens have a greater ventral distance between spermathecal pores than other populations (0.33–0.50 vs. 0.28–0.29 body circumference) ( Rosa 1890; Gates 1972; Bantaowong et al. 2011). In addition, the genetic distance among Vietnamese specimens was from 3% ( Table 4 ) while that from Thailand and Malaysia is about 4.8% ( Prasankok et al. 2013; Jeratthitikul et al. 2017; Ng et al. 2017). The genetic distance between M. peguana peguana and other Metaphire species from 15.1%±1.6% (with M. bahli (type II)) to 23.5%±2.1% (with M. grandiverticulata ) ( Table 4 ).

Figures

FIGURE 3. Distribution of Metaphire peguana species-group recorded all over the word (A) and in the South of Vietnam (B). 1. Metaphire bahli, 2. M. doiphamon, 3. M. dorsomultitheca, 4. Metaphire kiengiangensis, 5. Metaphire nhuongi, 6. Metaphire peguana laisonensis, 7. M. peguana peguana.

FIGURE 4. Metaphire peguana peguana (Rosa, 1890). A. Ventral view of the male pore region, B. Right spermathecae, C. Right prostatic gland, D. Caecum, E. Ventral view of spermathecal region, F. Transverse body section of the male copulatory pouch, G. Transverse body section of accessory gland. Scale bar=1 mm.