Pheretima naawanensis sp. nov.

Fig. 3

Material examined.

Holotype • adult (PNM 4683), Brgy. Poblacion, Naawan, Misamis Oriental (8°26'24.5"N, 124°17'22.4"E), 164 m asl., Mindanao Island, Philippines, collectors: E. Castañares, 10 February 2020. Paratypes • adults (MSUN-A - 0003), same collection data as for holotype.

Etymology.

The species is named after the municipality of Naawan, Misamis Oriental, where it was collected.

Diagnosis.

Brown worm with adult length 82–100 mm, diameter 6–9 mm; equators pigmented; 67–120 segments; three pairs of spermathecal pores at 6 / 7 / 8 / 9. Spermathecae large with ovate ampulla, stalked diverticulum terminating in sausage-shaped receptacles; paired small copulatory bursae in xvii-xviii; genital markings lacking; caeca simple originating in xxvii, extending forward to xxiii; prostates large in xvii to xix; penis present.

Description.

In live animals, dorsal brown, ventral pale, equators pigmented; Length 82–100 mm (n = 2 adults); diameter 6–9 mm at x, 7–8 mm at xx; body cylindrical in cross-section, tail blunt; 67–120 segments. First dorsal pore at 13 / 14; spermathecal pore three pairs at 6 / 7 / 8 / 9, inconspicuous, distance between spermathecal pores 5.2 mm (0.18 circumference apart ventrally). Female pore single in xiv, openings of copulatory bursae paired in xviii, extending to xxi, distance between openings 4.2 mm (0.17 circumference apart ventrally), 4–5 setae between openings. Clitellum annular, from xiv to xvi. Setae evenly distributed around segmental equators; 29–33 setae on vii, 69–71 setae on xx, dorsal and ventral setal gaps absent. Genital marking lacking.

Septa 4 / 5–8 / 9 muscular, and 9 / 10–10 / 11 thin, 11 / 12–13 / 14 muscular. Dense tufts of nephridia on anterior faces of 5 / 6 and 6 / 7; nephridia of intestinal segments located mainly on body near septum / body wall junction. Large gizzard extending from ix to xi, esophagus with low vertical lamellae x – xiii, intestinal origin xv, caeca simple originating in xxvii, extending forward to xxiii; Hearts in x to xiii, esophageal; commissural vessels in vi, vii, and ix, lateral.

Ovaries and funnels free in xiii. Three pairs of spermathecae in vii, viii, ix with nephridia on ducts; each spermatheca large with ovate ampulla, short muscular duct, stalked diverticulum attached to duct near ampulla, terminating in sausage-shaped receptacle, stalk thin. Male sexual system holandric, testes and funnels enclosed in paired sacs in x, xi; seminal vesicles xi, xii, each with digitate dorsal lobe; vesicles of xi enclosed in testes sac; vasa deferentia slender, free from body wall to ental end of prostatic ducts; prostates large in xvii to xix, each a single, dense, racemose mass; short muscular duct entering on lateral margin of copulatory bursa; copulatory bursae small in xvii – xviii; tapering penis present.

Remarks.

Pheretima naawanensis sp. nov., belongs to the Ph. dubia group of Sims and Easton (1972), characterized by having three pairs of spermathecal pores in 6 / 7–8 / 9. Members of the group include Ph. callosa Gates, 1937, Ph. poiana Michaelsen, 1913, Ph. philippina Rosa, 1981, Ph. losbanosensis Aspe & Obusan, 2023, Ph. korinchiana Cognetti, 1922, Ph. vungtauensis Nguyen et al., 2018, Ph. dubia Horst, 1893, Ph. julkai Hong & James, 2011, Ph. banaoi Hong & James, 2010, Ph. lamaganensis Hong & James, 2011, Ph. balbalanensis Hong & James, 2010, Ph. globosa Hong & James, 2011, and Ph. naawanensis sp. nov. In terms of the distance between spermathecal pores, the new species is similar to Ph. losbanosensis, a significantly larger worm, while the other members of the species group have a wider distance between male pores (0.19–0.4) (Table 3). Similar to Ph. dubia (0.17), the new species has a wider distance between male pores than that of Ph. losbanosensis (0.15) but has a narrower distance between male pores than that of the other members of the species group (0.18–0.29). In terms of length, Ph. naawanensis sp. nov. is relatively similar to Ph. korinchiana Cognetti, 1922, and Ph. dubia Horst, 1893. However, the new species has fewer preclitellar setae (29–33) and more postclitellar setae than the two species (38, 43, and 52, respectively). It also has fewer setae between male pores (4–5) than the two species (12 and 10, respectively). In addition, the new species has a narrower distance between spermathecal pores and between male pores (0.18 and 0.17, respectively) than Ph. korinchiana (0.19–0.22) and has a significantly narrower distance between spermathecal pores than Ph. dubia (0.38). Pheretima naawanensis sp. nov., is so far the only species belonging to the Ph. dubia group to be recorded from Mindanao Island, geographically isolated from any member of the species group.

Similar to Po. andresi sp. nov., Pheretima naawanensis sp. nov. has shown to have potential for vermiculture and has been explored in the College of Agriculture, Forestry, and Environmental Science of the Mindanao State University at Naawan for various applications such as in agriculture and aquaculture.