Drawida beiganica Shen & Chang

Shen, Huei-Ping, Chang, Chih-Han & Chih, Wen-Jay, 2015, Earthworms from Matsu, Taiwan with descriptions of new species of the genera Amynthas (Oligochaeta: Megascolecidae) and Drawida (Oligochaeta: Moniligastridae), Zootaxa 3973 (3), pp. 425-450 : 433-435

Drawida beiganica Shen & Chang , sp. nov.

( Figure 4 )

Holotype: Clitellate (mature) specimen (86 mm in total length, dissected), Beigan, along the road between Chinbi Village and Bishan Lookout, 26°13'22.7''N, 119°59'16.7''E, 210 m asl, 26 June 2012, H.P. Chen & W.J. Chih (TESRI-O-H-45; MTS 141).

Paratypes: 2 clitellates (one dissected, the other amputated), Nangan, Shengtien Reservoir, 26°09'13.9''N, 119°54'59.7''E, 70 m asl, 28 May 2012, H.P. Chen & T.L. Ai (TESRI-O-P-40).

Other material. 24 specimens altogether. 1 specimen (amputated), Beigan, from a roadside ditch at Chinbi Village, 26°13'32.0''N, 119°59'03.3''E, 11 m asl, 29 May 2012, H.P. Chen & T.L. Ai (TESRI-O- 2012-39 -13; MTS 30); 3 specimens, Beigan, in front of Matsu Broadcasting Station, 26°13'16.7''N, 119°58'47.5''E, 205 m asl, 29 May 2012, H.P. Chen & T.L. Ai (TESRI-O- 2012-43 -6; MTS 40); 12 specimens, Nangan, near Nangan Airport, 26°09'09.2''N, 119°57'17.1''E, 58 m asl, 31 May 2012, H.P. Chen & T.L. Ai (TESRI-O- 2012-55 -4); 1 specimen, Nangan, Stronghold No. 12, 26°10'02.5''N, 119°57'06.2''E, 59 m asl, 25 June 2012, H.P. Chen & W.J. Chih (TESRI-O- 2012-60 -9; MTS 91); 2 specimens, Beigan, Tangchi Village, near a trash treatment field, 26°13'59.9''N, 120°00'17.4''E, 64 m asl, 26 June 2012, H.P. Chen & W.J. Chih (TESRI-O- 2012-61 -11; MTS 99); 5 specimens, Beigan, along the road between Chinbi Village and Bishan Lookout, 26°13'22.7''N, 119°59'16.7''E, 210 m asl, 26 June 2012, H.P. Chen & W.J. Chih (TESRI-O- 2012-63 -13; MTS 109, 142).

Diagnosis. Length 55–86 mm, weight 0.31–0.69 g, diameter 3.2–4.8 mm. Segments numbering 120–169. Prostomium prolobous. Dorsal pores absent. Setae lumbricine, short and closely paired. Clitellum in X–XIII, paler, swollen. Spermathecal pores one pair in 7/8. Penes usually wholly concealed or slightly visible externally when in retracted condition, and long, conical, stouter at base and pointed forward when entirely protruded, with a slit-like male pore situated at its free end. Secondary male aperture transverse slits in 10/11. Female pores minute, hardly visible, one pair on anterior-most border of XII, each pore in line with seta b. Genital markings absent. Gizzards three in XIII–XV. Testis sacs one pair, large, each suspended on septum 9/10. Sperm duct long, in form of a large mass of white, twisted fine tubes. Male atrium S- or boomerang-shaped, its proximal end in connection with coelomic surface of penis pouch. Spermathecae one pair. Ampulla large, oval-shaped, with slender, coiled duct. Spermathecal atrium oval, sac- or thumb-like. Accessory glands absent.

Description. Length 55–86 mm (amputated specimens not included), weight 0.31–0.69 g, diameter 3.2–4.8 mm. Segments numbering 120–169. Prostomium prolobous. Dorsal pores absent. Setae lumbricine (eight setae per segment), short and closely paired, ab = cd, aa = 0.8 bc, aa> 6 ab, dd greater than 0.5 body circumference. Clitellum in X–XIII, paler, swollen. Spermathecal pores one pair in 7/8, each pore medial to seta c, slit-like, edge slightly wrinkled. Penes usually wholly concealed or slightly visible externally when in retracted condition, and long, conical, stouter at base and pointed forward when entirely protruded, with a slit-like male pore situated at its free end, the entire length about two segments ( Fig. 4 A). Secondary male aperture transverse slits between bc in 10/ 11, with whiter margin surrounded by swollen skin. Female pores minute, hardly visible, one pair on anterior-most border of XII, each pore in line with seta b. Genital markings absent. Preserved specimen grayish or pale gray, and paler or pink around clitellum.

Internal: Septa 5/6–8/9 thick and muscular, 9/10 thin. Gizzards three in XIII–XV, round, white, muscular and shining. Hearts four pairs in VI–IX. Nephridia holoic. Testis sacs one pair, large, yellowish, elongated oval, each suspended on septum 9/10, 1.78–1.95 mm in length and 1.65–1.75 mm in width. Sperm duct long, in form of a large mass of white, twisted fine tubes, running in front of septum 9/10, penetrating septum into segment X and passing along dorsal surface of the male atrium ( Fig. 4 B). Male atrium white, S- or boomerang-shaped, its proximal end in connection with coelomic surface of penis pouch. Penis pouch elevated as a dome-shaped bulge when penis retracted. Ovarian chamber formed by septa 10/11 and 11/12, meeting in front of the gizzard on dorsal side. One pair of follicular, yellowish ovisacs dorso-lateral on both sides of the digestive tract, extending posteriorly to segment XIV–XVI, broader anteriorly and narrower posteriorly, moniliform or constricted by each septum. Spermathecae one pair, ampulla anterior while spermathecal atrium posterior to septum 7/8. Ampulla large, oval-shaped, 1.25–1.38 mm long and 1.07 mm wide, its duct long, slender, at first straight and then passing into several coils to join the spermathecal atrium ( Fig. 4 C). Atrium oval, sac- or thumb-like, 0.65–0.8 mm in length and about 0.4 mm in width. Accessory glands absent.

DNA barcodes. GenBank accession numbers KJ782577 (MTS 141, holotype), KJ782578 , KJ782579 , KJ782582 , KJ782580 , KJ782581 and KJ782583 (MTS 30, 40, 91, 99, 109 and 142, respectively).

Etymology. The name beiganica is given to this species with reference to its type locality in Beigan, Matsu.

Remarks. Drawida beiganica sp. nov. is found on the islands of Beigan and Nangan. The shape of its penis is fairly similar to that of Drawida beddardii ( Rosa, 1890) from Burma. However, the penes of D. beddardii are much shorter with length a little more than half the segment (specimen No: 125407 of Smithsonian Institution, National Museum of Natural History identified by Gates and examined by H.P. Shen), while those of D. beiganica are about two segments long. Also, D. beddardii has large spermathecal pores ( Gates 1972) whereas those of D. beiganica are small slits. Furthermore, sperm ducts are rather short and not twisted in D. beddardii ( Rosa 1890; Gates 1972) and long, in form of a large mass of white, twisted fine tubes in D. beiganica . Beddard (1895), Michaelsen (1900), Stephenson (1923) and Blakemore et al. (2014) considered that D. beddardii is synonymous to Drawida barwelli ( Beddard, 1886) . Gates (1929) included D. beddardii in D. barwelli but later (1962) maintained these two species separately and stated that barwelli was never found in Burma. Also, Easton (1984) excluded D. beddardii as a synonym of D. barwelli . In the original brief description of Beddard (1886), sperm ducts of D. barwelli are thin, delicate and much coiled. However, sperm ducts of D. beddardii are quite short and not twisted ( Rosa 1890, Fig. 12). Obviously, D. beddardii is a valid species distinguishable specifically from D. barwelli .

Drawida tairaensis Ohfuchi, 1938 from Japan often lacks genital papillae and is fairly similar to D. beiganica externally when penes of both species are in retracted condition. However, the penes of D. tairaensis are short and pointing ventro-medially when entirely protruded ( Ohfuchi 1938). In addition, the spermathecal atrium of D. tairaensis is long, cylindrical and always situated in segment VII ( Ohfuchi 1938), while that of D. beiganica is oval, sac- or thumb-like and located in segment VIII.

Drawida beiganica is also similar to Drawida eda Blakemore, 2010 from Japan in body size and in having no genital markings. However, D. eda has inward-facing, comma-shaped penes, spermathecal ampulla on posterior face of septum 7/8, much shorter sperm ducts, and five gizzards in XIII–XVII ( Blakemore & Kupriyanova 2010), which differ greatly from those of D. beiganica .

Figures

FIGURE 4. Drawida beiganica sp. nov. Holotype (TESRI-O-H- 45). A. Ventral view of spermathecal and male pore region (one penis is shown everted and the other one is retracted) (sp, spermathecal pore; mp, male porophore). B. Dorsal view of right testis sac (ts), sperm duct (sd) and male atrium (ma). C. Dorsal view of left spermatheca (amp, ampulla; sa, spermathecal atrium). Scale bars = 1 mm.