Polypheretima zonadimidia, 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 : 775-776

Polypheretima zonadimidia sp. nov.

( Figure 16 )

Material examined

Holotype: adult ( MSUN-A013 ), Brgy. Pasadena, municipality of El Nido, (11.216°N, 119.450° E), 196 m asl, Palawan Province, Philippines, coll. S. James, 27 September 2005.

Etymology

The word ‘zonadimidia’ means half girdle or belt, referring to the clitellum that only partially encircles the body.

Diagnosis

Unpigmented worm with adult length 94 mm, diameter 3–3.2 mm; 120 segments; paired spermathecal battery pores at 7/8; 41 setae on vii, 50 setae on xx; 4 setae between male pores; male openings 0.10 circumference apart ventrally; clitellum brown, covering the dorsal and the laterals only but not the ventral side, from xiv to xvi; pairs of large discrete genital markings on xiv, xv, xvii and xix in line with male pores; two spermathecae in each battery in vii; spermathecal ampulla ovate, spermathecal duct short, slender; diverticulum short, attached ectally to duct, terminating in small, long receptacle; prostates in xvi–xix.

Description

Body unpigmented, equators unpigmented. Length 98 mm (n = 1 adult); diameter 3.2 mm at x, 3 mm at xx; body circular in cross section, tail blunt; 120 segments. First dorsal pore at 12/13, paired spermathecal battery pores at intersegment 7/8. Female pore single in xiv, openings of male pores paired in xviii, distance between pores 1 mm (0.10 circumference apart ventrally), 4 setae between pores. Clitellum brown, covering the dorsal and the laterals only but not the ventral side, from xiv to xvi. Setae unevenly distributed around equators in some segments; 41 setae on vii, 50 setae on xx, dorsal and ventral setal gaps present. Pairs of large, discrete genital markings on xiv, xv, xvii and xix, in line with male pores.

Septa 5/6–7/8 thick, 10/11–13/14 thin, 8/9/10 lacking. Dense tufts of nephridia on anterior faces of 4/5, 5/6 and 6/7; nephridia of intestinal segments located mainly on body near septum/body wall junction. Large gizzard in viii–x, oesophagus with low vertical lamellae x–xiii, intestinal origin in xiv, caeca lacking. Hearts in x–xiii, oesophageal; commissural vessels in vi, vii and ix lateral.

Ovaries and funnels free in xiii. Spermathecal battery paired in viii, with a total of 4 spermathecae, each battery with 2 spermathecae. Spermathecal ampulla ovate, spermathecal duct short, slender; diverticulum stalk short, attached ectally to duct, terminating in small, long 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 xi–xiii; pseudovesicles in xiii; vasa deferentia slender, free from body wall on way to ental end of prostatic ducts; prostates in xvi–xix, each prostate racemose, compact; muscular duct from lateral margin of prostate folds and is directed to the body wall; copulatory bursae lacking. Pairs of genital marking glands visible on xiv and xv.

Remarks

Polypheretima zonadimidia sp. nov. is unique among all Polypheretima species in having a saddle-shaped clitellum and in having a pair of genital markings on xiv and xv. The new species is most similar to Po. taprobanae Beddard, 1892 and Po. parataprobanae Thai and Nguyen, 1993 in Nguyen, 1993 in having a pair of spermathecal pores in 7/8 and in having a holandric male system. However, Po. trapobanae has pre- and post-clitellar genital markings, while Po. parataprobanae has genital markings on vii. In addition, the two species have only a pair of spermathecae in viii while the new species has two spermathecae in each battery in viii. The only other pheretimoid species that has a saddle-shaped clitellum is Metaphire setosa Nguyen et al. 2020a . However, Me. setosa has caeca on xxvii, has three pairs of spermathecal pores on 6/7/8/9, and has two setal rings in each segment that distinguish it from all other pheretimoid species.

Figures

Figure 16. Polypheretima zonadimidia sp. nov. (a) External ventral view. (b) Internal dorsal view. (c) Spermathecae. Abbreviations: c, clitellum; gm, genital markings; gmg, genital marking glands; mp, male pores; p, prostate gland s, spermathecae; sv, seminal vesicles.