Metaphire songkhlaensis 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 : 65-66

Metaphire songkhlaensis Bantaowong & Panha , sp. n.

( Figure 2 , Table 1 )

Material examined. Holotype: clitellate ( CUMZ 3373), Thailand, Songkhla, Hat Yai, Literary Botanical Garden, 07°01'11.1"N, 100°17'34.1"E, 89 m above mean sea level (amsl), 17 January 2014, leg. U. Bantaowong, C. Sutcharit, J. Tubtimon & W. Siriwut. Paratypes: 2 adults ( CUMZ 3374), 1 adult ( NHMUK), same data as holotype.

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

Diagnosis. Medium to large worms; length> 165–300 mm,>89–116 segments. Setae numbering 60–71 in VII, 74–89 in XX, 20–27 between male pores. Male pores paired, prominent in XVIII, genital markings as papillae in transverse rows on VIII–IX, XIX–XXII, 3–9 papillae per row. Spermathecal pores paired at 5/6–8/9, spermathecal ampulla elongated, sac-shaped, diverticulum rod-shaped. No nephridia on the spermathecal ducts. Holandric, intestinal caeca simple, first dorsal pore in 12/13. Prostate glands large, genital marking glands sessile.

Description of holotype. Dimensions: 300 mm by 9.0 mm at VII, 9.0 mm at XX, 10.0 mm at clitellum. Body cylindrical with 116 segments. Preserved specimen reddish-brown dorsally, grayish-brown ventrally. Setae regularly distributed around segmental equators, numbering 71 at VII, 74 at XX, 20 between male pores; setal formula AA:AB:ZZ:ZY=2:1:1:1 at XIII. Single female pore at XIV. Prostomium epilobic. First dorsal pore at 12/13. Clitellum annular XIV–XVI. Male apertures prominent on ventro-lateral sides in XVIII, 0.22 circumference apart ventrally, distance between apertures 6 mm, penes within small copulatory pouches or everted. Genital markings arranged in transverse rows, pre-setal in XIX–XXII, post-setal in XXI, XXII, each row consisting of 5–7 papillae. Four pairs of spermathecal pores, each marked by a whitish spot in furrows 5/6–8/9, ventral, distance between each pair about 0.37 circumference apart ventrally, distance between spermathecal pores 11 mm on body circumference. Genital papillae arranged in transverse rows centered on mid-ventral line, pre-and post-setal in VIII, IX; four per row in VIII, five per row in IX.

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; the intestinal caeca originating in XXVII, simple, extending to XXIV. Typhlosole rudimentary. Oesophageal hearts four pairs in X–XIII. Holandric; testes and funnels enclosed in paired sacs in X and XI, sacs not connected. Seminal vesicles paired in XI–XII, large, well-developed. Prostate glands well-developed, large, occupying segments XVII to XIX. Prostatic duct c-shaped, copulatory pouch located within the body wall with conical penis extending outwards to opening. Genital marking glands sessile, corresponding to external genital papillae. Ovaries and funnels in XIII. Four pairs of spermathecae in VI–IX. Ampulla as an elongate sac with short duct; diverticulum rod-shaped in terminal portion, stalk irregular.

Variation. The holotype is the only complete specimen, with 300 mm body length and 116 segments; all three paratypes are incomplete, longer than 165 mm and with more than 89 segments. There is variation in the number of genital papillae per row: 3–9 papillae on pre-clitellum and 6–8 papillae on post-clitellum. One paratype specimen has an additional papilla in VII and three in XXIII.

Distribution. This species lives in the top soil at about 10–15 cm depth, in the watercourse where it contributed to sedimentary organic matter accumulation, in the Literary Botanical Garden.

Remarks. Metaphire songkhlaensis sp. n. is octothecal with spermathecal pores in 5/6–8/9, keying out with the pulauensis species group in Sims and Easton (1972), which consists of two species, M. pulauensis ( Beddard, 1900) and M. baruana ( Stephenson, 1932) from Malaysia. Metaphire songkhlaensis sp. n. is easily distinguished from the two known species of this group by the higher setal number ( Table 1 ). Further important differences are number, shape and position of the genital markings. Metaphire songkhlaensis sp. n. has transverse rows of papillae situated in segments VIII, IX, XIX–XXII; each papilla is associated with an internal glandular mass. M. baruana has only one field of papillae near the male pore area, on segment XVIII. M. pulauensis has numerous genital markings in sieve-like fields on VII, VIII, IX, XVII and XVIII; each of the 40-50 glands per field correspond to an internal granular mass, but these masses are much less developed than in M. songkhlaensis . A further difference is the distance between the openings of the copulatory pouches and number of setae in between: Metaphire songkhlaensis has 20 setae between the openings; these are 0.22 body circumference apart (holotype). M. baruana and M. pulauensis have 10–17 setae between the openings; these are 0.25 body circumference apart. Table 1 summarizes information on the characters that separate the members of the pulauensis species group.

Figures

FIGURE 2. External and internal morphology of Metaphire songkhlaensis sp. n., holotype (CUMZ 3373). A. External ventral view. B. Internal dorsal view. C. Spermatheca; arrowhead: location of spermathecal pore.