Pheretima globosa, Hong & James, 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 : 23

Pheretima globosa , new species

( Figs. 4 A–B)

Material examined. – Holotype: One clitellate ( NMA 4388 ), Philippines, Ilocos Norte Province, Pagudpud, Kalbaryo (18°33.59'N 120°57.50'E), 175 m, litter layers in the forest, coll. Y. Hong, A. Castillo & M. Levi, 3 Jun.2001 . Paratypes: 1 clitellate ( NMA 4394 ), 1 clitellate ( KUNHM), 1 clitellate ( NIBR), 1 clitellate ( ZRC): same data as for holotype .

Other material: 15 clitellates and 5 aclitellates, same data as for holotype ( NMA) .

bursae without coelomic glands; copulatory bursa openings flanked by anterior and posterior circular pads, penis only small bump on copulatory bursa roof.

Remarks. – Pheretima globosa , new species, keys to the dubia group in Sims and Easton (1972), which is composed of five species, P. philippina (Rosa, 1891) , P. callosa Gates, 1937 , P. dubia ( Horst, 1893) , P. korinchiana Cognetti, 1922 , and P. poiana Michaelsen, 1913 . The present species is small, with body length 35–42 mm, and 71–80 segments, but P. poiana and P. philippina are large worms, greater than 180 mm in length with more than 110 segments. Pheretima callosa is large bodied (330 by 16 mm), has at least twice as many setae per segment as Pheretima globosa , new species, pseudovesicles in xiii and xiv, and thickly conical penes with deep cleft on the tips. Pheretima callosa is from the Diagnosis. – Three pairs of spermathecal pores in 6/7– 8/9; spermathecal pores and male pores 0.32 and 0.22 circumference ventrally apart, respectively.

Etymology. – The name globosa is Latin for spherical, here referring to the shape of the spermathecal diverticula seminal chamber.

Description. – Light brown dorsal pigment. Dimensions 35–42 mm by 2.3–2.5 mm at segment x, 2.5–2.7 mm at xxx, 2.5–2.6 mm at clitellum, segments 71–80; body cylindrical in cross-section. Setae regularly distributed around segmental equators, numbering 29 at vii, 52 at xx; 9 between male pores; size, distance irregular; setal formula AA:AB:YZ: ZZ = 1:1:1:2 at xiii. Clitellum annular in xiv–xvi; setae invisible externally.

First dorsal pore in 11/12, three pairs of spermathecal pores in 6/7–8/9, very small, distance between spermathecal pores 2.4 mm (0.32 circumference ventrally apart). Female pore single in xiv, on 0.3 mm oval, 0.3 mm openings of copulatory bursae paired in xviii, distance between male pores 1.7 mm (0.22 circumference ventrally apart). Genital markings absent.

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

Ovaries and funnels in xiii, spermatheca in vii–ix with nephridia on spermathecal ducts; spermatheca with spherical ampulla, duct shorter than ampulla, diverticulum seminal chamber egg-shaped. Male sexual system holandric, testes and funnels in ventrally paired sacs in x, xi. Seminal vesicles two pairs in xi, xii with dorsal lobes. Prostates in xvii–xviii, with short muscular duct entering center of the copulatory Philippines, Luzon Island, Benguet Province at 2,130 m asl in oak forest, so is geographically the nearest neighbor among the dubia group. Pheretima philippina is from Mindoro, a more southerly island in the Philippines. Pheretima dubia is only twice the length of Pheretima globosa , new species, and has spirally twisted spermathecal diverticula. Pheretima korinchiana is also much larger (90–180mm), has violetbrown dorsal pigment, 12 setae between the male pores, laterally placed spermathecal pores, and a club-shaped diverticulum on an undulating or spiral stalk. Ignoring for the moment the numbers and locations of spermathecae that define the dubia -group, the present species is otherwise very close to the overall morphological pattern of the three species described here for the darnleiensis -group. It seems reasonable to hypothesize that Pheretima globosa , new species is derived from a darnleiensis -group ancestor, by loss of the anterior pair of spermathecae. James (2005) presents preliminary molecular evidence that similar reductions from the darnleiensis -group spermathecal battery have taken place in other Philippine Pheretima species.

Figures

Fig. 4. Pheretima globosa, new species: A, ventral view; B, spermathecae and diverticulum. Scale bars = 3 mm (A), 1 mm (B).