Metaphire saxicalcis 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 : 78-79

Metaphire saxicalcis Bantaowong & Panha , sp. n.

( Figure10 )

Material examined. Holotype: clitellate ( CUMZ 3392), Thailand, Chonburi, Bo Thong, Khao Cha Ang On, 13°12'0.7"N, 101°34'43.6"E, 82 m amsl, 24 September 2012, leg. S. Panha, U. Bantaowong, R. Chanabun & W. Siriwut. Paratypes: 6 adults ( CUMZ 3393), 1 adult ( ZMH), 1 adult ( NHMUK), same data as holotype.

Other material examined. 4 adults ( CUMZ 3394), Thailand, Chonburi, Bo Thong, Khao Ha Yod, 13°9'46.5"N, 101°35'52.3"E, 93 m amsl, 24 September 2012.

Diagnosis. Large Metaphire worms; length 254–377 mm with 147–157 segments. Setae numbering 80–89 in VII, 89–98 in XX, 13–20 between male pores. Male pores paired, secondary apertures transversely slit-like with puckered margin on segment XVIII, no genital markings. Spermathecal pores paired in segments 6/7–7/8. Spermathecae with large paddle-shaped ampulla, duct thin, and with large saccular body at its base. Diverticulum slender, longer than ampulla, with enlarged spindle-like seminal chamber. No nephridia on the spermathecal duct. Holandric, intestinal caeca simple, first dorsal pore in 12/13. Prostate glands large, its elongate spindle-shaped duct connected to center of the large circular copulatory sac.

Etymology. The specific epithet is from the Latin "saxi calcis" = limestone. The habitat of the new species is a limestone forest.

Description of holotype. Dimensions 377 mm length by 9.6 mm width at segment VII, 9.5 mm at segment XX, 9.6 mm at clitellum; body cylindrical with 151 segments. Preserved specimen dark-brown dorsally, lightbrown ventrally; clitellum brown to dark-brown. Setae regularly distributed around segmental equators, numbering 89 at VII, 96 at XX, 20 setae 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 12/13. Clitellum annular XIV–XVI.

Male pores in copulatory pouches, these with very conspicuous, transversely slit-like apertures with puckered margins on ventro-lateral sides of segment XVIII, about 0.28 circumference apart ventrally, distance between apertures 8 mm on body circumference. Spermathecal pores two pairs, latero-ventral, each pore with transverse slits on somewhat raised glandular areas in furrows 6/7–7/8, about 0.34 body circumference apart ventrally, distance between spermathecal pores 10 mm on body circumference.

Septa 5/6–7/8 thick, 8/9–9/10 absent, 10/11–11/12 thin. Gizzard large behind 7/8, intestinal origin XV; intestinal caeca originating in XXVII, simple and extending to XXII. Typhlosole rudimentary. Oesophageal hearts four pairs in X–XIII. Holandric; testes small, two pairs in ventrally joined sacs in X and XI. Seminal vesicles paired in XI–XII. Prostate glands in XVI–XXI, expanded into a fan-shaped outline wrapped around copulatory sacs. Duct large and long, looped in a hairpin-shape with enlarged spindle-shaped ectal half, entering into the large round cushion-like copulatory sac. Ovaries in XIII. Spermathecae large, in VII and VIII; ampulla large, paddleshaped, with saccular body at the base of spermathecal ducts, duct thin and not sharply marked off from the ampulla. Diverticulum slender, very long, length as long as main part of spermathecae, seminal chamber enlarged, spindle-like with pebbly outer texture.

Variation. The eight paratypes are 254–285 mm long (271.6± 21.9 mm) and with 147–157 segments. Setae between male pores vary from 11 to 18. Prostate glands may extend to XXII, and intestinal caeca to XXIII only.

Distribution. Known only from the type locality and one further site from Khao Ha Yod, Chonburi, which is located approximately 15 km south-west of the type locality.

Remarks. Metaphire saxicalcis sp. n. keys out with the planata species group in Sims and Easton (1972). This group consists of six species, M. dunckeri ( Michaelsen, 1902) , M. parvula ( Ohfuchi, 1956) , M. sintangi ( Michaelsen, 1922) , M. ferdinandi ( Michaelsen, 1891) , M. planata ( Gates, 1926) , and M. decipiens ( Beddard, 1912) , the latter placed in synonymy with Pheretima darnleiensis ( Fletcher, 1886) by Blakemore et al. (2007). Metaphire saxicalcis sp. n. is easily distinguished from these species by the greater body length of 254–377 mm, while all of these five species members have body length less than 200 mm. Furthermore, none of the species have the saccular body at the spermathecal ducts that we observed in M. saxicalcis .

Figures

FIGURE 10. External and internal morphology of Metaphire saxicalcis sp. n., holotype (CUMZ 3392). A. External ventral view. B. Internal dorsal view. C. Spermatheca; arrowhead: location of spermathecal pore.