Pheretima bontocensis, Hong & James, 2021

Hong, Yong & James, Samuel W., 2021, Two new earthworms of the Pheretima sangirensis species group (Clitellata Megascolecidae) from Mountain Province, Philippines, Zootaxa 4995 (2), pp. 357-366 : 359-365

Pheretima bontocensis sp. nov.

( Fig. 2 , Table 1)

urn:lsid:zoobank.org:act:C774ADA2-4780-4000-B1E2-6F44BC7A7527

Material examined. Holotype: Clitellate ( NMA 4630 ): Philippines, Mountain Province, 1200 m asl, arboreal, 5 April, 2001, S. W. James coll.

Paratypes: 2 clitellates ( NMA 4638 , NMA 4639): same data as for holotype .

Non-types: 3 semiclitellates, same data as for holotype.

Etymology. The species is named for its type locality.

Diagnosis. Dimensions 68–83 mm by 3.4–4.5 mm. Setal numbers 38–43 at VII, 56–67 at XX, 4–6 between male pores. One pair of spermathecal pores in 7/8. Copulatory bursae openings 0.10 circumference ventrally apart. Genital markings lacking.

Description. Violet-brown pigment dorsally, setal zones and ventral surface unpigmented. Dimensions 68–83 mm by 4–4.5 at segment X, 4.2–4.5 mm at XXX, 2.9–4 mm at clitellum, segments 75–106. Setae numbering 38–43 at VII, 56–67 at XX, 4–6 between male pores, ventral setae slightly more crowded; setal formula AA: AB: YZ: ZZ = 3: 2: 4: 5 at XIII. Clitellum annular XIV–XVI, setae invisible externally. First dorsal pores in 12/13. One pair of spermathecal pores in 7/8 at 6th setal lines, deep in furrow, ventrally placed, 0.09 circumference apart. Female pore single in XIV. Openings of copulatory bursae 0.4–0.5 mm in width, paired in XVIII at 7th setal lines, ventrally placed, distance between openings 1.5 mm, 0.10 circumference apart. Genital markings lacking.

Septa 5/6, 6/7, 7/8 thinly muscular, 8/9, 9/10 incomplete, reduced to a few muscular fibers or absent, 10/11– 13/14 slightly muscular. Gizzard in VIII–X; intestine enlarged from XVI; small paired lymph glands from XXVIII along dorsal vessel; intestinal caeca simple, originating in XXVII and extending anteriorly to about XXIV, with finger-shaped sac; typhlosole 1/3 lumen diameter; 28–30 intestinal blood vessels. Hearts in X–XIII esophageal, X very small, commissural vessels of VII lateral, VIII to gizzard. Ovaries and funnels in XIII. Spermathecae in VII, with nephridia on ducts; spermatheca with a transversely ovate ampulla and a short, broad muscular duct shorter than ampulla; diverticulum with an iridescent, elongated oval-shaped seminal chamber and a kinked stalk. Male sexual system holandric, testes and funnels in ventrally paired sacs in X–XI. Seminal vesicles two pairs in XI–XII, dorsal lobes not distinct; prostates in XVII–XVIII, small, 2 main lobes, with short muscular ducts entering posterior face of the copulatory bursae; bursae without stalked glands, openings internally surrounded by four wedge-shaped pads; short angular penis from bursal roof, about half depth of the bursa; possibly glandular tissue on roof medial to penis.

Remarks. Pheretima bontocensis sp. nov. is also in the P. sangirensis group, and is distinguished from other species of the group by the combination of its character states for the pigmentation pattern (violet brown with equatorial pale stripes), the origin of the intestine (XVI), the location of the spermathecae (VII) and the forms of spermathecae, diverticula, and copulatory bursae. Pheretima bontocensis sp. nov. follows the same set of comparisons as P. riparianensis (see above) and is most similar to that new species.

Pheretima bontocensis sp. nov. differs from P. riparianensis sp. nov. in having fewer setae per segment in XX, and slightly closer spacing of the openings of copulatory bursae (0.10 vs. 0.11 or 0.12). Pads in the copulatory bursae are also different, with P. riparianensis sp. nov. having a ring of small wedge-shaped pads, where P. bontocensis sp. nov. has but four wedge shaped pads. P. riparianensis sp. nov. is a slightly larger worm than P. bontocensis sp. nov. (75–105 vs. 68–83 mm).

Like P. riparianensis sp. nov., the new species is most similar to P. floresi , P. baracatanensis and P. solisi . However, P. bontocensis sp. nov. has penes, but P. floresi , P. baracatanensis and P. solisi has no penes. Also the number of bursal pads are different (2 pads in P. floresi , 3 pads in P. baracatanensis , and 2 pads in P. solisi ).

Table 1 summarizes the characteristics and differences of the species in the Pheretima sangirensis group.

Figures

FIGURE 2. Pheretima bontocensis sp. nov. (A, B). A: ventral view; B: spermatheca. Scale bars = 2.5 mm (A), 2 mm (B).