Polypheretima irawanensis, Aspe & Manasan & Manlavi & Patiluna & Sebido & Obusan & Simbahan & James, 2021

Aspe, Nonillon M., Manasan, Rafael Ethan, Manlavi, Albert B., Patiluna, Ma. Lotus E., Sebido, Maria Asela B., Obusan, Marie Christine M., Simbahan, Jessica F. & James, Samuel W., 2021, The earthworm fauna of Palawan, Philippines with description of nineteen new pheretimoid species (Clitellata: Megascolecidae), Journal of Natural History 55 (11 - 12), pp. 733-797 : 762-764

Polypheretima irawanensis sp. nov.

( Figure 11 )

Material examined

Holotype: adult ( WPU-A016 ), Brgy. Irawan, Puerto Princesa City, (9.783°N, 118.650°E), 200 m asl, Palawan Province, Philippines, coll. E. Manasan, A. Manlavi, 5 October 2018 . Paratypes: one juvenile ( WPU-A 017), same collection data as for holotype.

Etymology

The species is named after Brgy. Irawan in Puerto Princesa City, Palawan, where the species was collected.

Diagnosis

Brown worm with adult length 174 mm, diameter 6.5–7 mm; 178 segments; first dorsal pore at 11/12; two pairs of spermathecal battery pores at 5/6/7; 94 setae on vii, 79 setae on xx; 11 setae between male pores; male openings 0.22 circumference apart ventrally; paired genital markings widely spaced on xix–xxii, in line with male pores; six spermathecae closely aligned on either side of vi; 12 spermathecae closely aligned on either side of vii; spermathecae small, ampulla ovate, spermathecal duct short, slender; diverticulum short, attached ectally to duct, terminating in ovate receptacle; small prostates in xvii–xviii.

Description

Light brown, equators unpigmented. Length 174 mm (n = 1 adult); diameter 6.5 mm at x, 7 mm at xx; body circular in cross section, tail tapering; 178 segments. First dorsal pore at 11/12. Clitellum annular, from xiv to xvi. Setae unevenly distributed around equators in some segments; 94 setae on vii, 79 setae on xx, dorsal and ventral setal gaps present. Two pairs of spermathecal battery pores at intersegments 5/6/7, female pore single in xiv, male porophores elevated; male pores located deeply inside copulatory pouches in xviii; copulatory pores crescentic; distance between openings 4.9 mm (0.22 circumference apart ventrally), 11 setae between openings. Paired genital markings widely spaced on xix–xxii, in line with male pores; one individual lacks genital marking on the left of xxii.

Septa 4/5/6 muscular and 13/14 thin, 8/9/10 lacking. Dense tufts of nephridia on anterior faces of 5/6 and 6/7; nephridia in intestinal segments located mainly on body near septum/body wall junction. Large gizzard in viii–ix, oesophagus with low vertical lamellae x–xiii, intestinal origin in xv; caeca lacking. Hearts in x–xiii, oesophageal; commissural vessels in vi, vii and ix lateral.

Ovaries and funnels free in xiii. Spermathecal batteries paired, postseptal in vi and vii. A total of 12 spermathecae on vi, with 6 spermathecae closely aligned I each battery; a total of 24 on vii, with 12 spermathecae closely aligned in each battery. Spermathecae small, ampulla ovate, spermathecal duct short, slender; diverticulum short, attached ectally to duct, terminating in ovate receptacle; no nephridia on spermathecal ducts. Male sexual system holandric, testes and funnels enclosed in paired ventral sacs in x and xi; seminal vesicles in x–xii; the seminal vesicles in x extend forward to viii or ix; pseudovesicles in xiii; vasa deferentia slender, free from body wall on way to ental end of prostatic ducts; small prostates in xvii–xviii, each prostate racemose, compact; muscular duct from lateral margin of prostate widens towards body wall, then narrows slightly just before body wall; copulatory bursae shallow.

Remarks

Polypheretima irawanensis sp. nov. belongs to the Po. elongata species group of Easton (1979). Among the members of the Po. elongata group, Po. irawanensis sp. nov. is most similar to Po. victoriaensis sp. nov. in many features including pigmentation, size, number of segments, number of setae, genital markings and number of spermathecae in each battery in vi ( Table 2). However, the new species has its first dorsal pore at 11/12 (vs at 12/ 13 in Po. victoriaensis sp. nov.), has less space between male pores (0.22 circumference apart ventrally vs 0.25–0.26 circumference apart ventrally in Po. victoriaensis sp. nov.), has more spermathecae in each battery in vii (12 vs 9 in Po. victoriaensis sp. nov.), and has ovate spermathecal ampulla and ovate receptacle (vs pyriform ampulla and round receptacle in Po. victoriaensis sp. nov.). Polypheretima irawanensis sp. nov. is similar to Po. bukidnonensis and Po. mindanaoensis in the distance between male pores but the new species is larger (174 mm × 6.5–7 mm vs 90–131 mm × 5–7 mm), has more segments (178 vs 140–147), has its first dorsal pore in 11/12 (vs 12/ 13 in the two latter species) and has more setae on vii and xx (94 and 79, respectively, vs 39–53 and 44–58, respectively, in the two latter species), among other differences.

Figures

Figure 11. Polypheretima irawanensis sp. nov. (a) External ventral view. (b) Internal dorsal view. (c) Spermathecae. Abbreviations: fp, female pores; gm, genital markings; mp, male pores; p, prostate gland; s, spermathecae; sp, spermathecal pores; sv, seminal vesicles.