Metaphire hijauensis Ng & Panha, 2018

Ng, Beewah, Bantaowong, Ueangfa, Tongkerd, Piyoros & Panha, Somsak, 2018, Description of two new species of the earthworm genus, Metaphire (Clitellata: Megascolecidae), from Kedah, Peninsular Malaysia, Raffles Bulletin of Zoology 66, pp. 132-141 : 136-139

Metaphire hijauensis Ng & Panha , new species

( Fig. 2 ; Table 3)

Material examined. Holotype: One adult ( CUMZ 3674 ), Bukit Hijau, Kedah, Malaysia, 5°30′04.5″N, 100°46′19.1″E, coll. B.W. Ng, J.Y. Sam & S.P. Yeap, 23 July 2016 , Paratypes: 6 adults ( CUMZ 3675 ) , 2 adult paratypes deposited at LKCNHM ( ZRC.ANN.0376), same collection data as for holotype .

Other material examined. One adult ( CUMZ 3676 ), Sedim, Kedah, Malaysia, 5°24′48.6″N, 100°46′51.3″E, coll. B.W. Ng, J.Y. Sam & S.P. Yeap, 23 July 2016 .

Diagnosis. Small size, length 66–87 mm, diameter 3.05 mm at the clitellum, segments 101–120. Prostomium epilobic. First dorsal pore in 10/11. Spermathecal pores minute paired in intersegment 6/7/8/9. Male pores paired in XVIII, within copulatory pouches. Spermathecae three pairs, in segments VII–IX, large sac-shaped ampulla with long duct. Diverticulum with elongated tubular and twisted shape attached to duct. Holandric, intestinal caeca simple. Prostate glands large, duct C-shaped.

Description of holotype. External characters. Body length 87 mm, diameter 3.05 mm at clitellum, 118 segments. Prostomium epilobic. First dorsal pore at 10/11. Clitellum annular at XIV–XVI, with setae. Setal numbering 34 in VI, 34 at VII, 48 in VIII, 55 in XX, 56 in XXX and 8 between male pores in XVIII. Single female pore at XIV.

Male pores paired in XVIII, 0.244 circumference ventrally apart, each in copulatory pouches, rounded-shaped opening, distance between male pores 3 mm. Genital markings absent. Three pairs spermathecal pores, in furrows 6/7–8/9, slit like, 0.455 body circumference apart, distance between spermathecal pores 5 mm. No genital markings observed at spermathecal pore area.

Internal characters. Septa, 5/6–7/8 and 10/11–13/14 thickened, 8/9 and 9/10 aborted. Gizzard large within IX–X. Last heart in XIII. Intestinal origin at XV. Intestinal caeca originating in XXVII, simple, extending to XXIV.

Ovaries in XIII. Three pairs spermathecae in VII–IX. Big sac-shaped ampulla with long duct. Diverticulum with elongated tubular, twisted-shaped stalk attached to duct. Pair of elongated thin sac-shaped genital marking glands next to the spermathecae.

Holandric. Testes sacs paired in X and XI. Seminal vesicles paired in XI and XII. Prostate glands paired in XVIII, racemose, large, occupying segments XVI–XIX. Prostatic duct C-shaped.

Variation. The holotype measures 87 mm in body length with 118 segments; the paratypes ranged in size from 66–80 mm body length with 101–120 segments.

Etymology. This new species was named after the type locality (Bukit Hijau).

Distribution. This new species are found from the type locality and Sedim, Kedah. The distance between the two localities was about 24 km.

Habitat. Found inside a ditch covered with sandy loam soil (pH 5.88), at about 10 cm depth and very close to a garbage bin. Casts were observed on the top of the soil.

Remarks. Metaphire hijauensis , new species, belongs to the sexthecal group, with spermathecal pores in 6/7–8/9, without any genital markings. This species keys out with the houlleti group, to which Sims & Easton (1972) assigned 40 species, and 11 of which were recorded from adjacent countries in Southeast Asia, namely: Metaphire mamillana ( Gates, 1931) , M. umbraticola ( Gates, 1932) , and M. quadrigemina ( Gates, 1932) from Myanmar; M. amplectens (Michaelsen, 1934) and M. dawydovi (Michaelsen, 1934) from Vietnam; M. bindjeynsis ( Michaelsen, 1899) from Sumatra, Indonesia; M. khaoluangensis Bantaowong & Panha, 2016 , M. perichaeta (Beddard, 1900) , M. virgo (Beddard, 1900) , and M. khaochamao Bantaowong & Panha, 2016 from Thailand; and M. houlleti ( Perrier, 1872) , which is widespread in East and South-East Asia. Metaphire houlleti , M. mamillana , M. perichaeta and M. virgo are also found in Malaysia.

Metaphire hijauensis , new species, is fairly similar to M. mamillana and M. quadrigemina in body size, but it is easily distinguished from M. mamillana and M. quadrigemina by the position of the first dorsal pore and the position of intestine origin. The first dorsal pore is on 10/11 for M. hijauensis ( Fig. 2 ), new species, while that of M. mamillana ( Gates, 1931: p. 400, Fig. 33) and M. quadrigemina ( Gates, 1932: p. 486) are on 12/13. As for the intestine origin, it originates at XV for M. hijauensis , new species, whereas the intestine of M. quadrigemina begins in XVI. Posterior portion of XV or anteriorly in XVI are the intestine origin for M. mamillana . In addition, M. hijauensis , new species, can be distinguished from these two species by the intestinal caeca originating

a M. houlleti collected during this study ( MF479443 , CUMZ 3805).

b M. houlleti (KU565270.1, CUMZ 3460), c M. khaoluangensis (KU565276.1, CUMZ 3466), d M. songkhlaensis (KU565294.1, CUMZ

3374A) and e M. trangensis (KU565319.1, CIMZ 3376A) from Jeratthitikul et al. (2017).

f M. sedimensis ( MF479444 , CUMZ 3672) and g M. hijauensis ( MF479445 , CUMZ 3674) from this study.

in XXVII and extending to XXIV, while in the latter two species it is found in XXVII–XX.

Metaphire hijauensis , new species, can be distinguished from the regional species recorded from Vietnam ( M. amplectens and M. dawydovi ), Myanmar ( M. umbraticola ), Sumatra ( M. bindjeynsis ), and Thailand ( M. khaoluangensis , M. perichaeta , M. khaochamao , and M. virgo ), and from the cosmopolitan species ( M. houlleti ), by the aspects of body size, number of segments and the location of the first dorsal pore. The shape of spermathecal significantly separates M. hijauensis ( Fig. 2 ), new species, from M. amplectens (Michaelsen, 1934: p. 501) and M. dawydovi (Michaelsen, 1934: p. 517) . Metaphire dawydovi has flask-shaped ampullae with small diverticulum and M. amplectens has obclavate ampullae with zigzag diverticulum, while M. hijauensis , new species, has big sac-shaped ampullae with elongated tubular and twisted diverticulum. The new species is very close to M. houlleti , but differs in the form of male pores. The male pores of M. hijauensis are round while in M. houlleti they are C-shaped slits ( Bantaowong et al., 2011: p. 59, Fig. 3 ). Additionally, numerous long-stalked genital marking glands, with a round or slightly lobed head are present near the spermathecae in M. houlleti , whereas M. hijauensis , new species, has only one genital marking gland next to each spermatheca. The character comparisons between M. hijauensis , new species, and the other closely species are presented in Table 3.

Figures

Fig. 2. Metaphire hijauensis new species (holotype). A, external ventral view; B, internal dorsal view; C, enlarged viewed of spermatheca.

Fig. 3. Molecular affiliation of M. sedimensis new species, and M. hijauensis new species, based on ML analysis of the CO1 DNA barcode sequence, with Pontodrilus litoralis as the out-group. Bar represents the number of nucleotide substitutions per site. Codes before the species name are the museum reference number, whilst those afterwards are the GenBank sequence accession numbers, Jeratthitikul et al. (2017).