Pheretima libradoi, Aspe & James, 2017

Aspe, Nonillon M. & James, Samuel W., 2017, Pheretimoid earthworms (Clitellata: Megascolecidae) from Mt. Apo, Mindanao Island, Philippines with description of eight new species, Raffles Bulletin of Zoology 65, pp. 357-372 : 367-370

Pheretima libradoi , new species

( Fig. 2C )

Material examined. Holotype: adult ( NMP 4623 ), Brgy Baracatan , Davao City , Mt. Apo National Park (7°00′04″N, 125°21′55″E), 1,524 m asl, Mindanao Island, Philippines, coll. N. Aspe, 11–14 December 2003.

Etymology. The species is named after Randolph Librado, a relative of the first author, who assisted in the fieldwork.

Diagnosis. Purplish brown worm with body dimension 185 mm × 7.3–8 mm; one pair of spermathecal pores at 5/6; distance between spermathecal pores and male pores both 0.10 circumference apart ventrally; intestinal origin in xv; spermatheca with a large ovate ampulla and a slender duct; prostates extending from xv–xvii anterior to the copulatory bursae; penis lacking.

Description. Purplish brown dorsum, lighter ventrum, equators non-pigmented. Length 185 mm (n= 1 adult); diameter 7.3 mm at x, 8 mm at xx; body cylindrical in crosssection, tail tapering; 185 segments. First dorsal pore 12/13. One pair of spermathecal pores at 5/6, distance between spermathecal pores 2.3 mm (0.10 circumference ventrally apart). Female pore single in xiv. Openings of copulatory bursae depressed, paired in xviii, distance between openings 2.5 mm (0.10 circumference apart ventrally); no setae between openings. Clitellum annular, from xiv to xvi. Setae on ventrum more closely spaced compared with that of the dorsum, 30 setae on vii, 59 setae on xx, dorsal and ventral setal gaps present. Genital markings lacking.

Septa 4/5/6, 12/13/14 membranous, 6/7/8, 10/11/12 muscular, 8/9 thin, 9/10 lacking. 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 in viii–x, esophagus with low vertical lamellae x–xiii. Intestinal origin in xv, caeca simple originating in xxvii, extending forward to xxiv. Typhlosole originating in xxvii, simple fold, 1/3 lumen diameter. Intestinal wall with 32 longitudinal blood vessels. Hearts in x to xiii, esophageal; commissural vessels in vi, vii, and ix lateral; those in viii extending to gizzard.

Ovaries and funnels free in xiii. Spermathecae paired, postseptal in vi, with nephridia on ducts; each spermatheca with a large ovate ampulla and a slender duct, diverticulum attached to the ental portion of the right face of the right spermathecal duct, and to left face of the left spermathecal duct, stalks long, slender, terminating in sausage-shaped receptacles. Male sexual system holandric, testes and funnels enclosed in paired sacs in x, xi; seminal vesicles in xi, xii, each with a digitate dorsal lobe; vesicles of xi enclosed in testss sacs; vasa deferentia slender, free from body wall en route to ental end of prostatic ducts; prostates located anterior to copulatory bursae in xv to xvii; each prostate a single, dense, racemose mass, with two lobes; thick duct entering posterior margin of copulatory bursa. Copulatory bursae ovate in xvii–xix; coelomic surfaces muscular, secretory diverticula lacking; one pad present on roof, floor with folding; penis lacking.

Remarks. Pheretima libradoi , new species belongs to the P. urceolata species group of Sims & Easton (1972). The new species is relatively similar to P. aquila , new species, P. buhiensis and P. gorasi in body size. However, the latter three have significantly fewer body segmentations (94 in P. aquila and 117–119 in P. buhiensis and P. gorasi ). The distance between spermathecal pores in P. buhiensis (0.04–0.06 circumference apart) and P. gorasi (0.06–0.07 circumference apart) are closer while it is significantly wider in P. aquila (0.22 circumference apart). Likewise, the distance between male pores in P. aquila are significantly wider (0.22 circumference apart). In addition, P. buhiensis and P. gorasi have penes while the new species has none. No other species in the P. urceolata group closely resemble P. libradoi .

Figures

Fig. 2. Schematic drawings of the internal morphology in dorsal view. A, Pheretima aquila, new species; B, P. gamay, new species; C, P. libradoi, new species; D, P. davaoensis, new species. Abbreviations: s, spermatheca; h, heart; p, prostate gland; cb, copulatory bursa; c, caecum. Scale bars = 5 mm.