Pheretima viracensis, Hong, Yong & James, Samuel W., 2009

Hong, Yong & James, Samuel W., 2009, New earthworms of the Pheretima urceolata species group (Oligochaeta: Megascolecidae) from southern Luzon, Philippines, Zootaxa 2059, pp. 33-45 : 37-38

Pheretima viracensis sp. nov.

( Fig. 1 C–D)

Material. Holotype: Clitellate (NMA 004316): Philippines, Catanduanes province, Catanduanes Island, S. of Summit village on Virac-Viga Road, 21 May 2001, S. W. James coll. Other material: 1 clitellate, Same data as for holotype.

Etymology. The species is named for its type locality.

Diagnosis. One pair of spermathecal pores deep in 5/6 at 7th setal lines, openings of copulatory bursae 0.20 circumference apart.

Description. Solid dark violet brown dorsal pigment, light brown ventral pigment I–XIII. Dimensions 38–61 mm by 2.0–2.2 at segment X, 2.2–2.6 mm at XXX, 1.9–2.5 mm at clitellum, segments 83–96; body circular in cross-section. Setae numbering 37–38 at VII, 40–45 at XX; 7–10 between male pores, size and distance regular between dorsal and ventral, setal formula AA:AB:YZ:ZZ= 2.5:2.5:2.5:3 at XIII. Clitellum annular XIV–XVI; setae invisible externally.

First dorsal pores 11/12. One pair of spermathecal pores deep in 5/6 at 7th setal lines sub-laterally placed, 0.32–0.36 circumference apart, distance between spermathecal pores 2.0– 2.5 mm; 0.2–0.3 mm openings of copulatory bursae, paired in XVIII at 6th setal lines, lateral placed, 0.20 circumference apart, distance between opening 1.2–1.6 mm. Genital markings lacking.

Septa 5/6–7/8 thick 8/9/10 absent, 10/11–13/14 thin. Gizzard in VIII–X, intestine begins in XVI, small paired lymph glands from XXVII along dorsal vessel; intestinal caeca simple originating in XXVII, and extending anteriorly about to XXV, finger-shaped sac; typhlosole low simple fold from XXVII. Hearts XI–XIII esophageal, X absent.

Ovaries and funnels in XIII. Spermathecae paired in segments VI, with nephridia on ducts; spermatheca with small broad oval-shaped ampulla, flattened by gut, duct shorter than ampulla; diverticulum large eggshaped chamber, iridescent, with short stalk. Male sexual system holandric, testes and funnels in ventral paired sacs in X–XI. Seminal vesicles two pairs in XI–XII, elongate dorsal lobes in clefts; prostates in XVII–XIX, mainly lateral to copulatory bursae, with thin muscular straight ducts, entering center of copulatory bursae without stalked glands; copulatory bursae with large glandular anterior pad; penis wedge shaped on roof; narrow angular appendage parallel to penis on roof, lateral end free.

Remarks. Pheretima viracensis sp. nov. has widely spaced spermathecal pores (0.32–0.36 circumference) but only ordinary male opening spacing (0.2). Others in the species group with wide spermathecal pore spacing, hearts in XI–XIII and an intestinal origin in XVI are Pheretima doriae sp. nov., P. abiadai , and P. nagaensis (Table 1). Among these, Pheretima viracensis sp. nov. is the only one lacking ventral setal gaps, and the only one with a single copulatory bursal pad, the others having three or four.

Figures

FIGURE 1. Pheretima bicolensis sp. nov. A: ventral view; B: spermatheca. Pheretima viracensis sp. nov. C: ventral view; D: spermatheca. Pheretima camarinensis sp. nov. E: ventral view; F: spermatheca. Scale bars = 2.5 mm (ventral views), 1 mm (spermathecae).