Pheretima bicolensis, 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 : 34-37

Pheretima bicolensis sp. nov.

( Fig. 1 A–B)

Material. Holotype: Clitellate (NMA 004315): Philippines, Catanduanes province, Catanduanes Island, near village of Summit, 275 m, lowland forest, 22 May 2001, S. W. James coll. Other material: 2 clitellates, 1 aclitellate, same data as for holotype.

Etymology. The species is named for the region of the type locality.

Diagnosis. One pair of narrowly separated spermathecal pores in 5/6, no typhlosole, interior bursal pads two on the floor and one on the roof.

Description. Medium brown to dark brown dorsal pigment, unpigmented ventrally except on I–III. Dimensions 71–98 mm by 3.8–4.6 at segment X, 4.0–4.1 or 4.0 mm at XXX, 3.5–4.2 mm at clitellum, segments 91–122; body circular in cross-section. Setae numbering 29–34 at VII, 49–55 at XX; 2–3 between male pores, size larger in anterior dorsal segments, dorsal spacing greater, setal formula AA:AB:YZ:ZZ= 3:2.5:5.5:5 at XIII. Clitellum annular XIV–XVI; setae invisible externally.

First dorsal pores 12/13. One pair of spermathecal pores in 5/6 at 3rd setal lines, near mid-ventral; spermathecal pores 0.05–0.06 circumference apart, distance between spermathecal pores around 0.6–0.9 mm; 0.3–0.4 mm openings of copulatory bursae paired in XVIII at 7th setal lines, ventrally placed, 0.14 circumference apart, distance between openings 1.7 mm. Genital markings lacking.

TABLE 1. Comparison of species of the urceolata group (modified from James 2004).

Pigment red brown violet- light brown red-brown red-brown light brown brown

brown

* Setal gaps presence: D (dorsal), V (ventral)

** Septum present: +, Septum absent: -

***F= floor R= roof, S= side of copulatory bursa interior.

Septa 5/6–7/8 thinly muscular; 8/9, 9/10 absent, 10/11–13/14 thick. 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 XXIV, finger-shaped sac; typhlosole vestigial from XXVII. Hearts in XI–XIII esophageal; X absent.

Ovaries and funnels in XIII, spermathecae in VI, with nephridia on ducts; spermatheca with large eggshaped ampulla, narrow non-muscular duct shorter than ampulla; diverticulum small oval chamber; iridescent, undulating slender stalk about half spermatheca length. Male sexual system holandric, testes and funnels in ventrally paired sacs in X–XI. Seminal vesicles two pairs in XI–XII, dorsal lobes large, pear-shaped or elongate, apically attached, prostates in XVII–XVIII, 4 main lobes lateral-anterior to copulatory bursae, thick slightly muscular short ducts, entering center of copulatory bursae without stalked glands; copulatory bursae openings flanked anterior, posterior by oval pads on floor; one smaller pad on roof medial to penis; glandular tissue in chamber, male pore on roughly ovate-conical penis from copulatory bursa roof.

Remarks. Pheretima bicolensis sp. nov. keys to the urceolata group in Sims & Easton (1972), which is composed of eight species, P. urceolata ( Horst, 1893) , P. b a w e a n e n s i s ( Michaelsen, 1924), P. baletei James, 2004 , P. bukidnonensis James, 2004 , P. h e a n e y i James, 2004, P. kitangladensis James, 2004 , P. monotheca James, 2004 , and P. s i m s i James & Hong, 2004 plus two more currently in press, P. abiadai and P. nagaensis ( Hong and James 2008b). All comparisons to previously published species are confined to the urceolata group. Morphological data on this group is summarized in Table 1. The reader should refer to this table for all the comparisons made below.

Pheretima bicolensis sp. nov. has narrowly spaced spermathecal pores, a condition it shares with Pheretima buhiensis sp. nov. and Pheretima gorasi sp. nov. (See Table 1). Compared to those species, its male pores are more widely spaced, it has only ventral setal gaps, has 2 or 3 rather than zero setae between the male openings, lacks a typhlosole, and lacks septa 8/9/10. Pads in the copulatory bursae are also different, with those of Pheretima bicolensis sp. nov. being 2 on the bursal floor and one on the roof. The arrangement is reversed in Pheretima buhiensis sp. nov. (one on the floor, two on the roof), and Pheretima gorasi sp. nov. has only two pads, one of which is on the side. Of these three species, Pheretima bicolensis sp. nov. is the smallest.

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).