Metaphire trangensis Bantaowong & Panha

Bantaowong, Ueangfa, Chanabun, Ratmanee, James, Samuel W. & Panha, Somsak, 2016, Seven new species of the earthworm genus Metaphire Sims & Easton, 1972 from Thailand (Clitellata: Megascolecidae), Zootaxa 4117 (1), pp. 63-84 : 70-71

Metaphire trangensis Bantaowong & Panha , sp. n.

( Figure 5 )

Material examined. Holotype: clitellate ( CUMZ 3375), Thailand, Trang, Na Yong, Peninsular Botanical Garden, 7°32'57.1"N, 99°46'58.3"E, 9 m amsl, 16 January 2014, leg. U. Bantaowong, C. Sutcharit, P. Pimvichai & W. Siriwut. Paratypes: 21 adults ( CUMZ 3376), 2 adults ( ZMH), 2 adults ( NHMUK), same data as holotype.

Etymology. This species is named after the province where it was collected.

Diagnosis. Medium-sized; length 120–169 mm with 100–152 segments. Setae numbering 70–83 in VII, 78–92 in XX, 14–20 between male pores. Male pores paired, secondary openings round, wrinkled radially around margin in segment XVIII, genital markings absent. Spermathecal pores paired in 5/6–8/9. Ampulla oval, diverticulum ellipsoidal, knob-shaped in the terminal portion. No nephridia on the spermathecal duct. Holandric, intestinal caeca simple, first dorsal pore in 11/12. Prostate glands large, its duct C-shaped, with round copulatory sac.

Description of holotype. Dimensions 155 mm by 7.3 mm at segment VII, 7.3 mm at segment XX, 7.6 mm at clitellum; body cylindrical with 100 segments. Preserved specimen reddish-brown dorsally, light grayish brown ventrally. Setae regularly distributed around segmental equators, numbering 70 at VII, 88 at XX, 20 between male pores, setal formula AA:AB:ZZ:ZY=1:1:1:1 at XIII. Single female pore at XIV. Prostomium epilobic. First dorsal pore at 11/12. Clitellum annular XIV–XVI. Male pores on XVIII, secondary openings transversely oval, wrinkled radially around margins, 0.27 circumference apart ventrally, distance between openings of copulatory pouches 6 mm. Spermathecal pores four pairs, epidermis around each pore slightly wrinkled, in furrows 5/6–8/9, ventral, pores about 0.40 body circumference ventrally apart, distance between spermathecal pores 10 mm on body circumference. No genital markings in the spermathecal pores region.

Septa 5/6–7/8 thick, 8/9–9/10 absent, 10/11–11/12 thin. Gizzard large behind 7/8, intestinal origin in XV, intestinal caeca originating in XXVII, simple, extending to XXI, typhlosole rudimentary. Oesophageal hearts four pairs in X–XIII. Holandric; testes and funnels enclosed in paired sacs in X and XI. Seminal vesicles paired in XI– XII. Prostate glands large, extending anteriorly to XVII, posteriorly to XXI. Prostatic duct C-shaped, coiled around round copulatory sac in XVIII; coiled clockwise left side, anti-clockwise right side. Ovaries in XIII. Spermathecae four pairs in VI–IX. Ampulla large, oval with much shorter duct sharply marked off from the ampulla, diverticulum ellipsoidal with tubercle of circular outline, slightly dilated to form a small ovate knob.

Variation. The 25 paratypes are 120–169 mm long (142.53± 15.24 mm), with 100–113 segments. The prostate glands may begin in XVI and end in XXII, and the intestinal caeca may extend to XXIV only.

Distribution. Known only from the type locality. The species was found at about 10–15 cm soil depth.

Remarks. Metaphire trangensis sp. n. is octochaetal with spermathecal pores in 5/6–8/9, and it has no genital markings. This species keys out with the ignobilis species group, which contains six species ( Sims & Easton 1972): M. dalatana ( Michaelsen, 1934) and M. langbiangi ( Michaelsen, 1934) from Vietnam, M. ignobilis ( Gates, 1935) from China, M. feuerborni (Michaelsen, 1932) from southern Sumatra, M. riukiuensis ( Ohfuchi, 1957) and M. tosaensis ( Ohfuchi, 1938) from Japan. The first four species are smaller than M. trangensis sp. n., their body length and diameter not exceeding 100 mm and 2.5–3 mm, respectively. The two species from Japan are about as large as M. trangensis sp. n. The new species differs from them in the aspect of the male field. The secondary male openings of M. trangensis sp. n. have the shape of transverse slits invaginated into segment XVIII, while M. riukiuensis has seminal grooves from segment XVII to XIX, and M. tosaensis has male openings on slightly elevated oblong areas. Moreover, both M. riukuiensis and M. tosaensis have serrate intestinal caeca and elongate spermathecal diverticula.

Figures

FIGURE 5. External and internal morphology of Metaphire trangensis sp. n., holotype (CUMZ 3375). A. External ventral view. B. Internal dorsal view. C. Spermatheca; arrowhead: location of spermathecal pore.