Pheretima nolani, Aspe, Nonillon M. & James, Samuel W., 2014

Aspe, Nonillon M. & James, Samuel W., 2014, New species of Pheretima (Oligochaeta: Megascolecidae) from the Mt. Malindang Range, Mindanao Island, Philippines, Zootaxa 3881 (5), pp. 401-439 : 422-423

Pheretima nolani n. sp.

( Fig. 6 B, Table 2)

Material examined. Holotype: adult (NMA 4520) Brgy Sibucal, Oroquieta City, Misamis Occidental Province, Mt. Malindang Range (8º19'31"N, 123º38'02"E), 900 m asl., Mindanao Island, Philippines, coll. Nonillon Aspe, M. Lluch, and J. Adeva, Feb. 18–25, 2004. Paratypes: two adults ( ZRC.ANN.0028), Brgy Lake Duminagat, municipality of Don Victoriano, Misamis Occidental Province, Mt. Malindang Range (8º17'55"N, 123º37'01"E), 1500 m asl., coll. Nonillon Aspe, Nolan Aspe and J. Adeva, Oct. 9–15, 2003.

Etymology. The species is named after Nolan Aspe, who assisted in the fieldwork.

Diagnosis. Worm reaching 89–97 mm in adult length; body purplish brown; one pair of spermathecal pores at 7/8; spermathecae small, irregular, knobby, with short, thick duct; single-stalked diverticula terminating in sausageshaped receptacle; intestinal origin in xv; prostate glands from xv to xx; caeca extending from xxvii to xxii; 42–44 intestinal vessels.

Description. In living animals, dorsum purplish black anteriorly, fading to medium brown posteriorly; narrow equators non-pigmented; ventral side non-pigmented. Length 89–97 mm (n= 2 adults); diameter 5 mm at x; 4.5 mm at xx; body cylindrical in cross-section, tail narrowing gradually to sharp point; 111 segments. First dorsal pore at 12/13; paired spermathecal pores at 7/8, 0.14 circumference apart ventrally; female pore single on xiv; openings of copulatory bursae paired on xviii, 0.12 circumference apart ventrally, 2 setae between openings. Clitellum annular, extending from xiv to xvi. Setae on ventrum more closely spaced compared with that of the dorsum, 33–48 setae on vii, 42 setae on xx, dorsal gap present, ventral gap absent.

Septa 5/6/7/8 thinly muscled, 8/9 membranous, 9/10 absent, 10/11–13/14 slightly muscular. Dense tufts of nephridia on anterior faces of 5/6 and 6/7; nephridia of intestinal segments located mainly on body wall at anterior and posterior faces of septa, at septum/body wall junction. Large gizzard extending from viii to x; esophagus with lamellae extending from xi to xiii; intestine originates in xv; caeca originates in xxvii, extends forward to xxii, with serrate ventral margins; typhlosole a simple fold of about 1/6 lumen diameter, originating at 26/27; intestinal wall with 42–44 longitudinal blood vessels.

Hearts in x to xiii, esophageal; commissural vessels in vi, vii, and ix, lateral; supra-esophageal vessel extends from x to xiii; extra-esophageal vessels join ventral esophageal wall in x, receive efferent parieto-esophageal vessels in xiv.

Ovaries and funnels free in xiii; paired spermathecae pre-septal in vii, with nephridia on ducts. Spermatophores spherical, with small appendage. Male sexual system holandric; testes and funnels enclosed in paired sacs in x and xi; seminal vesicles in xi and xii, each with short dorsal lobe; vasa deferentia slender, free from body wall, passing around anterior face of copulatory bursae en route to ental end of prostatic ducts; prostates in xv to xx, each racemose, 4 lobes, wrapped around lateral margin of copulatory bursa, muscular duct attached over most of its length to lateral face of copulatory bursa, running along surface and entering dorsal face. Two or 3 ductlets from anterior prostatic lobe join vas deferens; 2 or 3 posterior ductlets join at common junction with muscular prostatic duct. Copulatory bursae hemispherical extending from xvii to xix; coelomic surface of each bursa muscular, secretory diverticula lacking. Floors of bursae with some folds adjacent to opening but lacking pads; roofs with small posterior pad, large penis attached to anterior internal wall of bursa, only the tip free; copulatory bursae lack penial sheaths.

Remarks. This species belongs to the P. sangirensis group of Sims & Easton (1972). It differs from all subspecies of P. sangirensis in having the spermathecal pores and male pores more closely spaced, in having fewer setae in the post-clitellar region, in having a septum in 8/9, and in having more extensive prostate glands. Among the Malindang sangirensis species, Pheretima nolani n. sp. is similar to P. wati n. sp. in having setal gaps and in the relative spacing between the spermathecal pores and between tne male pores, in the origins of the gizzard and intestine, and in the number of hearts. However, P. wati is smaller, has more setae around the equatorial segments, has fewer intestinal vessels, lacks penes, and lacks a septum at 8/9, whereas P. nolani lacks a septum at 9/10. The prostate of P. n ol a ni extends for 6 segments from xv to xx, whereas that in P. wati extends 8 segments from xv to xxii. The shape of the spermathecae also differs, and the copulatory bursae in P. nolani are shorter than in P. wati . Compared with Pheretima species from Mt. Kitanglad and Luzon Island, P. nolani is most similar to P. baungonensis James, 2004 in terms of the size, number, and location of spermathecae, but the latter is dark brown in color; lacks dorsal setal gaps; has the spermathecal pores and male pores spacings 0.32 circumference apart and 0.19 circumference apart, respectively; has the first dorsal pore is in 13/14; has smaller prostate glands and copulatory bursae; has fewer longitudinal intestinal vessels; and has penes.

Occurrence. Pheretima nolani was common than other species, especially in primary forest in Brgy Lake Duminagat; it was most abundant in the highest elevation range (1845–2027 m), but was not observed in Brgys Small Potongan and Toliyok, at lower elevations (Table 1).

Figures

FIGURE 6. Schematic drawings of the internal morphology of Philippine Pheretima species, in dorsal view: (A) P. longiprostata n. sp.; (B) P. nolani n. sp.; (C) P. longigula n. sp.; Abbreviations: s, spermatheca; h, heart; p, prostate gland; cb, copulatory bursa; c, caecum. Scale bars: 5 mm.