Pheretima wati, 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 : 419-420

Pheretima wati n. sp.

( Fig. 5 C, Table 2)

Material examined. Holotype: adult (NMA 4517) Brgy Sibucal, Oroquieta City, Misamis Oriental Province, Mt. Malindang Range (8º19'31"N, 123º38'02"E), 991 m asl., Mindanao Island, Philippines, coll. Nonillon Aspe, Nolan Aspe, M. Lluch, and J. Adeva, Feb. 18–25, 2004. Paratypes: five adults (NMA 4538), same collection data as for holotype. Other material: three adults ( ZRC.ANN.0022), 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 and J. Adeva, Oct. 9–15, 2003.

Etymology. The species name 'wati' is the word for small earthworm in Cebuano dialect.

Diagnosis. Small, purplish-brown worm reaching 67–75 mm in adult length; one pair of spermathecal pores at 7/8; male pores very closely spaced; relatively large, elongate spermathecae; intestinal origin in xv; caeca extending from xxvii to xxii; long prostate extending from xv to xxii, copulatory bursae elongate extending from xvii to xxi.

Description. Living animals purplish-brown dorsally, fading to yellow brown ventrally; equators pigmented. Length 67–75 mm (n= 9 adults); diameter 3.5–4.0 mm at x; 4.0 mm at xx; body cylindrical in cross-section, tail narrowing gradually to sharp point; 90–104 segments. First dorsal pore at 12/13; spermathecal pores paired at 7/8, 0.17 circumference apart ventrally; female pore single in xiv; depressed region where the copulatory bursae open in in xviii; copulatory bursae paired, 0.08 circumference apart ventrally, no setae between openings. Clitellum annular, extending from xiv to xvi. Setae more closely spaced on ventrum than on dorsum, 59–71 setae on vii, 52–60 setae on xx, dorsal gap present, ventral gap absent.

Septa 5/6–7/8 and 9/10–13/14 thin, 8/9 absent. 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. Gizzard large in viii to x; esophagus with low, vertical lamellae from x to xiii; intestinal origin in xv; caeca originate in xxvii, extend forward to xxii; typhlosole a simple fold about 1/3 lumen diameter, originating at 27/28; intestinal wall with 34–38 longitudinal blood vessels.

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

Ovaries and funnels free in xiii, spermathecae post-septal in viii, with nephridia on ducts; large glandular mass on interior ventral surface of viii, partially obscuring spermathecal ducts and diverticula; spermatheca with ovate to pyriform ampulla, slender muscular duct, stalked diverticulum attached ectally to duct, terminating in ovate receptacle; stalk shorter than spermathecal duct. One spermatophore present in each ampulla. Male sexual system holandric; testes and funnels enclosed in paired sacs in x and xi; seminal vesicles in xi and xii, each with short, round, knobby dorsal lobe; vasa deferentia slender, free from body wall en route to ental end of prostatic ducts; prostates in xv to xxii, each racemose with 5 or 6 separate lobes, distributed around dorsal-lateral margin of copulatory bursa; muscular duct enters posterior dorsal surface of copulatory bursa. Ductlets from anterior prostatic lobes join vas deferens and posterior ductlets at common junction with muscular prostatic duct. Copulatory bursae elongately bean-shaped extending from xvii to xxi. Coelomic surface of copulatory bursa muscular, secretory diverticula lacking; floors of bursae with medial longitudinal ridge, roofs with posterior glandular pad and penial platform with small, central peak; anterior half of bursa occupied by glandular mass.

Remarks. A member of the P. sangirensis group of Sims & Easton (1972), P. wati n. sp. is similar to all subspecies of P. sangirensis ; to P. nunezae n. sp., P. misamisensis n. sp., and P. longiprostata n. sp. From Mt. Malindang; and to P. baungonensis from Mt. Kitanglad (James 2004) in having the intestinal origin in xv. However, it has more setae on vii than the other species, and its male pores are much more closely spaced. Moreover, it differs from the others in the shape and length of the spermathecae, the septal arrangement (absent in 9/ 10 in P. baungonensis ), and the extent and shape of prostates and copulatory bursae (xvii–xix and xviii, respectively in P. baungonensis ), and the caeca are much shorter in P. baungonensis . The new species is similar to P. vicinipora from Mt. Kitanglad (James, 2004) in having very closely spaced male pores, but the new species has its first dorsal pore in 12/13 (13/ 14 in P. vicinipora ), its spermathecal pores are more distant than in P. vicinipora (0.08), and its caeca and prostates are more extensive (xxvii–xxv and xvi–xix, respectively, in P. vicinopora ). Among the Malindang species, P. w a t i has the second most extensive prostate glands relative to body length after P. longiprostata ; the prostates extend across 8 segments from xv to xxii. Like P. tigris n. sp. and P. immanis n. sp., P. wati lacks penes, but unlike them, the male pores are very close together, though not joined as one. The glandular mass in viii is also unique.

Occurrence. Pheretima wati was found at all sites, at 238–2027 m asl, and was most common at 915–1024 m in Brgy Small Potongan. It occurred both in soil and above ground in substrates such as rotting logs. It was one of the more common species, comprising 11.8% of all worms collected (Table 1).

Figures

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