Pheretima monotheca, James, 2004

James, Samuel W., 2004, New Species Of Amynthas, Pheretima And Pleionogaster (Clitellata: Megascolecidae) Of The Mt. Kitanglad Range, Mindanao Island, Philippines, Raffles Bulletin of Zoology 52 (2), pp. 289-313 : 295

Pheretima monotheca , new species

( Figs. 1I, J )

Material examined. – Holotype - adult ( NMA 003977 ) Philippines, Mindanao Island, Bukidnon Province, Mt. Kitanglad Range , 18 km S, 17 km E of Baungon, 8 9' N, 124 45' E, 1800 m. elevation, coll. D. Balete, no date.

Etymology. – The species name refers to the single spermatheca present.

Description. – Medium brown dorsal pigment, body 62 x 2.9 mm (vii), 3.2 mm (x), 3.7 mm (xxv), 96 segments; body cylindrical in cross-section. First dorsal pore 12/13, spermathecal pore single, mid-ventral 5/6, female pore single in xiv, openings of copulatory bursae paired in xviii, 0.11 circumference apart in 4 th setal line, 3 setae between openings. Setae more crowded ventrally, 36 setae on vii, 32 setae on xx; in vii ZZ:YZ = 2.2, in xx ZZ:YZ = 2.5; no ventral gaps. Clitellum annular xiv-xvi; infolded slightly thickened epidermal area posterior to spermathecal pore on vi ( Fig. 1I ).

Septa 4/5-7/8 thin, 8/9, 9/10 absent, 10/11-12/13 slightly toughened but thin. Nephridia of post-clitellar segments pre- and post-septal on body wall; tufts of nephridia on anterior faces of septa 5/6, 6/7.

Large gizzard in viii, esophagus with chevron-patterned lamellae x-xv, pebble-grained xvi, valvular in xvii, intestinal origin xviii, simple caeca originating in xxvii, extending forward to xxiii; typhlosole xxvii-lxiii, simple fold one third lumen diameter; 26 longitudinal vessels in intestinal wall.

Hearts x-xiii esophageal, commissural vessels vi, vii, ix lateral; viii to gizzard. Supra-esophageal vessel x-xiv, extra esophageal vessel not traceable past x.

Ovaries and funnels free in xiii, spermatheca in vi with nephridia on spermathecal duct; single spermatheca with irregular sac-shaped ampulla, stout duct, two stalked diverticula terminating in sausage-shaped receptacles, stalks kinked, first kink closely adherent to spermathecal duct ( Fig. 1J ). Male sexual system holandric, testes and funnels enclosed in paired sacs in x, xi; sacs not connected; seminal vesicles xi, xii, with dorsal lobe; vasa deferentia slender, free from body wall en route to ental end of prostatic ducts; each prostate racemose with two major lobes, stout muscular duct entering center of muscular dome of copulatory bursa in xviii; glandular mass anterior to, communicating with copulatory bursa, elongate conical penis present, surrounded by sheath within bursae.

Remarks. – Pheretima monotheca keys to P. ambonensis ( Cognetti, 1913) in Sims & Easton (1972), but that species has its spermathecal pore in 7/8, is twice the body length, has twice the setae on the post-clitellar segments, the male openings are farther (0.2 circumference) apart, its intestinal origin is three segments more forward in xv, the spermatheca is in vii and its two diverticula have much shorter chambers and stalks ( Cognetti, 1913). By spermathecal pore location P. monotheca would belong to the urceolata species group, within which it would be the only monothecate member. Furthermore it has fewer setae than most of its group members. The male openings are very close together, corresponding to the single spermathecal pore, and the copulatory bursae have anterior glandular masses and penes. The single spermatheca in vi has two identical diverticula, probably the result of fusion of two spermathecae into one, as is likely the case in P. ambonensis . Monothecy is not known to be common among Pheretima (Pheretima) , where until now P. ambonensis was the only one recorded. However monothecate species are known from other genera of the Pheretima complex, including Pithemera (Sims & Easton, 1972; James, unpub.data).

Figures

Fig. 1. Spermathecae, and external views (ventral except as noted) showing spermathecal pores, female pores, male pores and if present, genital markings, of Pheretima kitangladensis (A, B), P. baletei (C, D), P. heaneyi (E, F), P. bukidnonensis (G. Lateral view of spermathecal pore, ventral view of female and male pores, H), and P. monotheca (I, J). Symbols: fp, female pore(s); mp, male pores; sp, spermathecal pores.