Pheretima solisi, 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 : 362-363

Pheretima solisi , new species

( Fig. 1E )

Material examined. Holotype: adult ( NMP 4619 ), 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, A. Solis, D. Flores, 11–14 December 2003 . Paratypes: two adults ( ZRC. ANN 0072 ), same collection data as for holotype .

Etymology. The species is named after Armando Solis, a friend of the first author, who assisted in the fieldwork.

Diagnosis. Small, brown worm with adult length 68–86 mm; segmental equator pigmented; one pair of spermathecal pores at 7/8; distance between spermathecal pores and male pores 0.18 and 0.15 circumference apart ventrally, respectively; a round spermathecal ampulla with a very large, bulbous muscular duct, diverticulum with a long, convoluted stalk terminating in a small, ovate receptacle; racemose prostates extending from xvi–xx; penis lacking.

Description. Brown dorsum, lighter ventrum, equators pigmented. Length 68–86 mm (n= 3 adults); diameter 2.8–3 mm at x, 3.5 mm at xx; body cylindrical in cross-section, tail tapering; 91–98 segments. First dorsal pore 12/13. Spermathecal pores at 7/8, distance between spermathecal pores 1.7 mm (0.18 circumference ventrally apart). Female pore single in xiv. Openings of copulatory bursae paired in xviii, distance between openings 1.7 mm (0.15 circumference apart ventrally); 3–5 setae between openings. Clitellum annular, from xiv to xvi. Setae unevenly distributed around equators in some segments; 35 setae on vii, 32–35 setae on xx, dorsal setal gaps present, no ventral gaps. Genital markings lacking.

Septa 4/5/6 membranous, 8/9, 10/11 thin, 11/12–13/14 muscular, 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, about 1/3 lumen diameter. Intestinal wall with 29 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 viii, with nephridia on ducts; each spermatheca with a round ampulla and a very large bulbous, muscular duct, diverticulum attached to the ental portion of the left face of the right spermathecal duct, and to right face of the left spermathecal duct, stalks long, convoluted, terminating in small, ovate 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 testis sacs; vasa deferentia slender, free from body wall en route to ental end of prostatic ducts; prostates in xvi to xx; each prostate a single, dense, racemose mass, with three lobes; muscular duct entering posterior margin of copulatory bursa. Copulatory bursae ovate in xvii–xix; coelomic surfaces muscular, secretory diverticula lacking; two pads present on roof, one pad present floor; penis lacking.

Remarks. Pheretima solisi , new species belongs to the P. sangirensis species group of Sims & Easton (1972). It is similar to P.s. chica, P. misamisensis , P. wati , P. longiprostata , P. asurgo ( Blakemore, 2006; James, 2004), and P. floresi , new species in relative size and in having pigmentation all over the dorsum, including the segmental equators. However, P. s. chica (0.25 circumference apart), P. misamisensis (0.3 circumference apart), P. asurgo (0.20 circumference apart), and P. floresi (0.21 circumference apart) have wider distance between the spermathecal pores and that of P. longiprostata is closer (0.16 circumference apart). With regards to the spacing between male pores, it is wide in P. s. chica ’s (0.20 circumference apart), P. misamisensis ’ (0.23 circumference apart), and P. floresi ’s (0.20 circumference apart) while that in P. wati is closer (0.08 circumference apart). Pheretima wati and P. misamisensis have more setae in general (52–71 and 42–51, respectively) while P. s. chica, P. longiprostata , and P. floresi have more post-clitellar setae (>60, 37–47, 45, respectively) and P. asurgo (24) has fewer pre-clitellar setae. Pheretima solisi also differs in the form of the spermathecae: P. s. chica and P. misamisensis both have reniform spermathecae, with P. s. chica ’s diverticulum with long stalk originating ectally and P. misamisensis ’ diverticulum terminating in blunt ovate receptacle; P. wati has pyriform spermathecal ampulla with diverticulum with short duct terminating in small ovate receptacle; P. longiprostata has transversely place oval spermathecal ampulla, with short thick muscular duct, and with diverticulum terminating in small ovate receptacle; P. asurgo has round spermathecal ampulla, with diverticulum terminating in sausage-shaped receptacle; and P. floresi has ovate spermathecal ampulla, with diverticulum terminating in elongated receptacle expanding terminally. In addition, P. s. chica, P. misamisensis , P. longiprostata , and P. asurgo have penes while the new species has none. No other species in the P. sangirensis group closely resemble the new species.

Figures

Fig. 1. A, Diagrammatic ventral view of Amynthas apongensis, new species showing the spermathecal pores (sp), clitellum (cl), male pores (m), and the pattern of the genital markings (gm). Schematic drawings of the internal morphology in dorsal view: B, A. apongensis, new species; C, Pheretima floresi, new species; D, P. baracatanensis, new species; E, P. solisi, new species. Abbreviations: s, spermatheca; h, heart; p, prostate gland; cb, copulatory bursa; c, caecum. Scale bars = 5 mm.