Pithemera donvictorianoi, Aspe & James, 2015

Aspe, Nonillon M. & James, Samuel W., 2015, New Polypheretima and Pithemera (Oligochaeta: Megascolecidae) species from the Mt. Malindang Range, Mindanao Island, Philippines, Journal of Natural History 49 (37), pp. 2233-2255 : 2249-2250

Pithemera donvictorianoi sp. nov.

( Figure 2D and 3D )

Diagnosis

White worm; adult length 41–58 mm; clitellum annular from xiv to xv; four pairs of spermathecal pores, 5/6–8/9; male pores closely spaced; intestinal origin in xiv; prostate glands from xvi–xix.

Material examined

Holotype: adult (NMA 4530), Mt. Malindang Range (8.2986°N, 123.6169°E), Barangay Lake Duminagat , municipality of Don Victoriano, Misamis Occidental Province, Mindanao Island, Philippines; 1357 m a.s.l; coll. Aspe et al., 9–15 October 2003 . Paratypes: two adults (NMA 4549 and ZRC.ANN.0015); both same collection data as for holotype .

Etymology

The species is named for the municipality of Don Victoriano, the type locality.

Description

White; clitellum dark brown. Length 41–58 mm (n = 3 adults); diameter 2.5–3.0 mm. at x; 2.5–3.0 mm at xx; body cylindrical in cross-section, tail blunt; 85–100 segments. First dorsal pore at 12/13; paired spermathecal pores in 5/6/7/8/9, inconspicuous; female pores paired in xiv; male pores on lateral faces of slightly elevated cones in xviii, 0.11 circumference apart, eight setae between openings. Clitellum annular, extending from xiv to xv. Setae evenly distributed around segmental equators, 42–48 setae on vii, 41–57 setae on xx; no dorsal or ventral gaps. Genital markings lacking.

Septa 5/6/7/8 slightly muscular, 8/9 absent, 9/10–12/13 thinly muscular. Dense tufts of nephridia on anterior faces of 5/6/7/8; nephridia of intestinal segments located at septum/body wall junction, mainly on body wall near anterior and posterior faces of septa. Gizzard large, from viii to ix; oesophagus with lamellar sections from xi to xiii; intestinal origin in xiv; caeca from xxii to xxi; typhlosole a simple fold of about one-sixth lumen diameter, originating in xxii, maximum diameter in xxiv; intestinal wall without longitudinal blood vessels.

Hearts in x–xii, oesophageal; commissural vessel in vi, vii and ix, lateral; viii extending to gizzard; supra-oesophageal vessel extending from x to xii; extra-oesophageal vessels joining ventral oesophageal wall in x, receiving efferent parietooesophageal vessels in xiv.

Ovaries and funnels free in xiii; ovisacs lacking; spermathecae four pairs in vi to ix; duct short, slender; ampulla small, narrow ovate; diverticulum stalk short, attached ectally to duct, terminating in short, ovate receptacle. Male sexual system holandric; testes and funnels enclosed in annular sacs in x and xi; with sacs enclosing hearts; seminal vesicles in xi–xii; vasa deferentia slender, free from body wall, joining ental end of prostatic ducts; prostates in xvi to xix; each prostate racemose, broad, 4-lobed, lobes deeply incised; ectal half of duct expands to form muscular spindle; ducts in hairpin loop. Ental portion of duct with three lumens. Copulatory bursae lacking.

Remarks

Pithemera donvictorianoi sp. nov. belongs to the Pi. pacifica group of Sims and Easton (1972) and is the only member of this species group so far reported from the Philippines. This group is characterised by having four spermathecae, with the first spermathecal pore in 5/6, in contrast to the Pi. bicincta group, members of which have the first pair of spermathecal pores in 4/5. Like the other Pithemera species on Malindang, it is white and lacks genital markings, and the caeca extend from xvii to xxi. Like Pi. duminagati sp. nov., it has smaller average body size than Pi. malindangensis sp. nov., and it has three pairs of dense tufts of nephridia, on 5/6/7/8, whereas Pi. malindangensis has only two pairs, on 5/6/7. Pithemera donvictorianoi differs from all other Philippine Pithemera species in that the clitellum extends from xiv through xv, rather than from xiv through half of xiv ( Table 2).

Occurrence

Pithemera donvictorianoi sp. nov. was rare, with only one individual collected inside a plot in disturbed forest in Barangay Toliyok, though we also detected it in disturbed forest in Barangay Lake Duminagat. The soil it inhabited was covered with thick leaf litter and roots, bryophytes and lichens. We did not observe it on rotten logs.

Figures

Figure 2. Schematic drawings of the external anterio-ventral area of (A) Polypheretima mindanaoensis sp. nov., (B) Pithemera malindangensis sp. nov., (C) Pithemera duminagati sp. nov. and (D) Pithemera donvictorianoi sp. nov. Abbreviations: fp, female pore; cl, clitellum; mp, male pore; gm, genital markings. Scale bars: 5 mm.

Figure 3. Schematic drawings of the internal morphology of (A) Polypheretima mindanaoensis sp. nov., (B) Pithemera malindangensis sp. nov., (C) Pithemera duminagati sp. nov. and (D) Pithemera donvictorianoi sp. nov. Abbreviations: s, spermatheca; n, dense tufts of nephridia; h, heart; p, prostate gland; c, caecum. Scale bars: 5 mm.