Pheretima nunezae, 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 : 414-415

Pheretima nunezae n. sp.

( Fig. 4 B, Table 2)

Material examined. Holotype: adult, amputee (NMA 4509), Brgy Sibucal, Oroquieta City, Misamis Occidental Province, Mt. Malindang Range (8º19'31"N, 123º38'02"E), 991 m asl., Mindanao Island, Philippines, coll. Nonillon Aspe, M. Lluch, and J. Adeva, Feb. 18–25, 2004. Paratype: one juvenile (NMA 4534), same data as for holotype.

Etymology. The species is named in honor of Dr. Olga Nuneza, one of our collaborators in the Malindang Biodiversity Research Program and a professor at Mindanao State University-Iligan Institute of Technology, Iligan, Philippines.

Diagnosis. Large worm, dark gray-brown dorsally, non-pigmented ventrally, clitellum gray; one pair of spermathecal pores at 7/8; septa from 4/5 to 13/14, except for 9/10; relatively small prostates extending from xvii to xix, copulatory bursae confined to xviii; 20–23 intestinal vessels.

Description. In living animals, dorsum dark gray-brown anteriorly, fading posteriorly; ventrum nonpigmented; equators non-pigmented; clitellum gray, darker than adjacent segments. Length of posteriorly incomplete worm 116 mm; diameter 8.5 mm at x; 9 mm at xx; body cylindrical in cross-section. First dorsal pore at 12/13; paired spermathecal pores at 7/8, 0.28 circumference apart ventrally; female pore single in xiv; openings of copulatory bursae paired in xviii, 0.22 circumference apart ventrally, 9 setae between openings. Clitellum annular, extending from xiv to xvi. Setae evenly distributed, 46 setae on vii, 51 setae on xx, dorsal gap present, ventral gap absent.

Septa 4/5/6/7/8 slightly muscular, 8/9 membranous, 9/10 absent, 10/11–15/16 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 ix to x; esophagus with wide-angled, chevron-shaped lamellae, extending from x to xiii; intestine originates in xv; caeca originate in xxvii, extend forward to xxiv, with pocketed ventral margin; typhlosole simple fold, about 1/8 lumen diameter, originating at 26/27. Intestinal wall with 20–23 longitudinal blood vessels.

Hearts in xi to xiii, esophageal commissural vessels in vi, vii, and ix lateral; those in viii extend to gizzard; extra-esophageal vessels join ventral esophageal wall in x, receive efferent parieto-esophageal vessels in xiv.

Ovaries and funnels free in xiii; spermathecae paired in vii, one preseptal and the other postseptal; spermathecae irregularly shaped, with nephridia on ducts; each spermatheca with angular, apically attached oval ampulla, short thick muscular duct with slight bulge for diverticulum attachment; single-stalked diverticulum attached to face of duct, terminating in thick, sausage-shaped receptacle, stalk shorter than receptacle. Each spermatheca contains 2 spermatophores. Male sexual system holandric; testes and funnels enclosed in paired sacs in x and xi; seminal vesicles in xi and xii, each with short, spherical dorsal lobe; vasa deferentia slender, free from body wall, passing around lateral face of copulatory bursae en route to ental end of prostatic ducts; each prostate racemose, with three lobes, extending from xvii to xix, wrapped around lateral margins of copulatory bursa; muscular duct attached to surface of copulatory bursa along entire length of latter and enters apex. Ductlets of lobes meet vasa deferentia at common junction with muscular prostatic duct. Copulatory bursae hemispherical in xviii; coelomic surface of bursa muscular, secretory diverticula lacking; bursal floor with 2 pads lateral to center; elongate fold with longitudinal groove extending across medial edges of each pad; opening composed of sphincter valve surrounded by narrow ring; bursal roof with pair of folds or pads medial to small, rounded quadrangular penial projection directed posteriorly; copulatory bursae lacking penial sheaths.

Remarks. Pheretima nunezae n. sp. belongs to the P. sangirensis group of Sims & Easton (1972). It differs from all subspecies of P. sangirensis in having a septum in 8/9, the gizzard originating in ix, hearts absent in x, and fewer intestinal vessels and setae in xx. It differs from P. ceramensis Cognetti, 1922 in the origin of the gizzard (viii in P. ceramensis ); the number of setae (60 setae per segment in P. ceramensis ; James 2004); the number of hearts and intestinal vessels (x–xiii and 36, respectively in P. ceramensis ); and the number of pads on the floor of the copulatory bursae. Pheretima nunezae n. sp. differs from most of the Malindang species in the sangirensis group in size, particularly in width (except that of P. maculodorsalis n. sp. and P. tigris n. sp.); in having wide spacing between the spermathecal pores and between male pores, especially in large worms; in the shape of the spermathecae and spermathecal diverticula; in the size and position of the prostate glands and copulatory bursae; in the number of intestinal vessels; and in the length of the caeca. No other species known in the Philippines resembles P. nunezae .

Occurrence. A few Pheretima nunezae were found in disturbed forest in Brgys Sibucal and Small Potongan at elevations of 902–1067 m asl; overall, it was one of the least common species, comprising 2.1% of all specimens collected (Table 1).

Figures

FIGURE 4. Schematic drawings of the internal morphology of Philippine Pheretima species, in dorsal view: (A) P. lago n. sp.; (B) P. nunezae n. sp.; (C) P. boniaoi n. sp. Abbreviations: s, spermatheca; h, heart; p, prostate gland; cb, copulatory bursa; c, caecum. Scale bars: 10 mm.