Pheretima davaoensis, 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 : 370-371

Pheretima davaoensis , new species

( Fig. 2D )

Material examined. Holotype: adult ( NMP 4625 ), 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, R. Librado, 11–14 December 2003 . Paratype: one adult ( ZRC. ANN 0076 ), same collection data as for holotype .

Etymology. The species is named after Davao City, its type locality.

Diagnosis. Brown worm with body dimension 86–98 mm × 3.5–4.5; one pair of spermathecal pores at 5/6; distance between spermathecal pores and male pores 0.28 and 0.27 circumference apart ventrally, respectively; intestinal origin in xvii; spermatheca with an ovate ampulla and a large bulbous, muscular duct expanding ectally; racemose prostates extending from xvii–xxi; penis present.

Description. Brown dorsum, lighter ventrum, equators pigmented. Length 86–98 mm (n= 2 adults); diameter 3.5–4.5 mm at x, 3.5–4.2 mm at xx; body cylindrical in cross-section, tail tapering; 93–95 segments. First dorsal pore 12/13. One pair of spermathecal pores at 5/6, distance between spermathecal pores 4 mm (0.28 circumference ventrally apart). Female pore single in xiv. Openings of copulatory bursae paired in xviii, distance between openings 3.6 mm (0.27 circumference apart ventrally); 10 setae between openings. Clitellum annular, from xiv to xvi. Setae unevenly distributed around equators in some segments; 44 setae on vii, 43–49 setae on xx, dorsal setal gaps present, no ventral gaps. Genital markings lacking.

Septa 5/6–8/9 thin, 10/11–13/14 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 xvii, intestine thinner before the origin of caeca; caeca simple originating in xxvii, extending forward to xx. Typhlosole originating in xxvii, low simple fold. Intestinal wall with 36 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 an ovate ampulla and a large bulbous, muscular duct expanding ectally, diverticulum attached to the ental portion of the right face of the right spermathecal duct, and to the left face of the left spermathecal duct, stalks short, 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 xvii to xxi; each prostate a single, dense, racemose mass; thick, muscular duct entering the central area of copulatory bursa from the posterior part of the prostate. Copulatory bursae ovate in xvii–xix; coelomic surfaces muscular, secretory diverticula lacking; roof with two pads; large conical penis present within the bursa.

Remarks. Pheretima davaoensis , new species belongs to the P. urceolata group of Sims & Easton (1972). It is relatively similar to P. urceolata , P. bukidnonensis (James, 2004) , P. baletei , P. heaneyi , P. kitangladensis (James, 2004) , P. simsi ( James & Hong, 2004) , and P. bicolensis ( Hong & James, 2009) in body size. However, P. urceolata (0.16 circumference apart), P. baletei (0.25 circumference apart), P. heaneyi (0.19–0.23 circumference apart), P. kitangladensis (0.13 circumference apart) and P. bicolensis (0.05–0.06 cicumference apart) have closer spacing between the spermathecal pores while that of P. bukidnonensis , is significantly wider (0.38 circumference apart). The distance between the male pores in these species is also shorter (0.11–0.24 circumference apart). There was no information on the distance between spermathecal pores and the distance between male pores in P. simsi . Pheretima simsi and P. baletei have have fewer pre-clitellar setae (31–33 and 24, respectively) and fewer setae between male pores (6–8) compared to the new species. In addition, P. baletei has faint pink colouration while P. simsi has significantly shorter caeca (xxvii–xxvi) and smaller prostates (xvii–xix). No other species in the P. urceolata group closely resemble P. davaoensis .

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.