Pheretima thaii, new, 2011

Hong, Yong & James, Samuel W., 2011, New Species Of Pheretima, Pithemera, And Polypheretima (Clitellata: Megascolecidae) From Kalbaryo, Luzon Island, Philippines, Raffles Bulletin of Zoology 59 (1), pp. 19-28 : 22

Pheretima thaii, new species

( Figs. 3 A–B)

ovate ampulla, duct shorter than ampulla, diverticulum seminal chamber egg-shaped, iridescent, as long as ampulla, stalks long. Male sexual system holandric, testes and funnels in ventrally paired sacs in x, xi. Seminal vesicles two pairs in xi, xii with dorsal lobes, vas deferens slender, not muscular. Prostates in xvii–xix, with short muscular duct entering center of the copulatory bursae without coelomic glands; copulatory bursa openings flanked by anterior and posterior circular pads, penis long with vertical slit pore on medial face.

Remarks. – Pheretima thaii, new species, has the same number of spermathecae as the previous two new species, Material examined. – Holotype: One clitellate (NMA 4387), Philippines, Ilocos Norte Province, Pagudpud, Kalbaryo (18°30.94'N 120°54.52'E), 408 m, litter layers in the forest, coll. Y. Hong, A. Castillo & M. Levi, 3 Jun.2001.

Diagnosis. – Four pairs of spermathecal pores in 5/6–8/9; spermathecal pores and male pores 0.5 and 0.2 circumference ventrally apart, respectively.

Etymology. – The species is named for Dr. Thai Tran Bai, a Vietnamese biologist who made many good contributions to the taxonomy of earthworms.

Description. – Dark brown dorsal and brown ventral pigment, intersegmental furrows and large circles around each seta unpigmented, these circles fuse where setae are closely spaced. Dimensions 60 mm by 2.1 mm at segment x, 2.3 mm at xxx, 2.5 mm at clitellum, segments 81; body cylindrical in cross-section. Setae more crowded ventrally in anterior segments, almost evenly distributed in posterior half, numbering 16 at vii, 24 at xx; 3 between male pores, size, distance irregular; setal formula AA:AB:YZ:ZZ = 1.5:1.5:4:7 at xiii. Clitellum annular in xiv–xvi; setae invisible externally.

First dorsal pore in 9/10, four pairs of spermathecal pores in 5/6–8/9, conspicuous, lateral (0.5 circumference). Female pore single in xiv, on 0.4 mm oval, 0.3 mm openings of copulatory bursae paired in xviii, 1.4 mm between male pores (0.2 circumference ventrally apart). Genital markings absent.

Septa 5/6–7/8 thin, 8/9, 9/10 absent, 10/11–13/14 thin. Gizzard in viii–x, intestine enlarged from xv, medium paired lymph glands from xxviii along dorsal vessel; intestinal caeca simple, originating in xxvi, and extending anteriorly about to xxiii, each consisting of a finger-shaped sac; typhlosole almost none. Hearts x–xiii esophageal; ix lateral.

Ovaries and funnels in xiii, spermathecae in vi–ix with nephridia on spermathecal ducts; spermatheca with small but it differs from them and P. darnleiensis in the much more widely spaced spermathecal pores, much smaller body size and presence of ventral pigment. Its spermathecal ampulla is as long as the diverticulum, unlike Pheretima kalbaryoensis, new species. The diverticulum shape is similar to that of Pheretima margaritata , new species, but other characters are different.

Figures

Fig.3. Pheretima thaii, new species:A, ventral view;B, spermathecae and diverticulum. Scale bars = 5 mm (A), 1 mm (B).