Drawida dongyinica Shen & Chih

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 : 435-436

Drawida dongyinica Shen & Chih , sp. nov.

( Figure 5 )

Holotype: Clitellate (mature) specimen (77 mm in total length, dissected), Dongyin, around Dongyong Reservoir, 26°22'12.1''N, 120°29'33.7''E, 40 m asl, 31 August 2012, H.P. Chen & H.H. Huang (TESRI-O-H-46; MTS 148).

Paratypes: 4 clitellates, Hsiyin, under a tree at Stronghold No. 33, 26°22'22.5''N, 120°28'13.9''E, 61 m asl, 28 June 2012, H.P. Chen & W.J. Chih (TESRI-O-P-41; MTS 143).

Other material. 10 specimens altogether. 1 specimen, Hsiyin, Chingshuiao, from roadside ditches, 26°22'44.3''N, 120°28'35.3''E, 15 m asl, 28 June 2012, H.P. Chen & W.J. Chih (TESRI-O- 2012-74 -7; MTS 144); 2 specimens, Hsiyin, near Northernmost Frontier, 26°22'56.9''N, 120°28'33.7''E, 79 m asl, 28 June 2012, H.P. Chen & W.J. Chih (TESRI-O- 2012-75 -4; MTS 145); 3 specimens, Hsiyin, from a roadside ditch near Stronghold No. 26, 26°22'12.0''N, 120°28'45.3''E, 19 m asl, 28 June 2012, H.P. Chen & W.J. Chih (TESRI-O- 2012-76 -7; MTS 146); 4 specimens, Dongyin, beside the Yanhsiu Fort, 26°21'35.5''N, 120°29'22.2''E, 19 m asl, 28 June 2012, H.P. Chen & W.J. Chih (TESRI-O- 2012-78 -8; MTS 147).

Diagnosis. Length 52–78 mm, weight 0.27–0.59 g, diameter 2.9–4.1 mm. Segments numbering 141–165. 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 in retracted condition. Secondary male aperture slit-like or semicircular in 10/11. Female pores minute, one pair on anterior-most border of XII, each pore in line with seta b. Genital markings absent. Gizzards three in XII–XIV. Testis sacs one pair, large, each suspended on septum 9/10. Sperm duct long, in a cluster of densely coiled loops, loosely coiled while passing along the upper edge of the male atrium and entering the dorso-anterior end of the male atrium. Male atrium S- or C-shaped, its lower end in connection with coelomic surface of penis pouch. Spermathecae one pair. Ampulla small, oval-shaped, with long, slender, coiled duct. Spermathecal atrium small, oval-shaped. Accessory glands absent.

Description. Length 52–78 mm (amputated specimens not included), weight 0.27–0.59 g, diameter 2.9–4.1 mm. Segments numbering 141–165. Prostomium prolobous. Dorsal pores absent. Setae lumbricine, short and closely paired, ab = cd, aa = 0.8 bc, aa> 5 ab, dd greater than 0.5 body circumference. Clitellum in X–XIII, paler, swollen. Spermathecal pores one pair in 7/8, small, inconspicuous slits, each pore medial to seta c. Penes in completely retracted condition, not visible externally in all specimens. Secondary male aperture slit-like or semicircular between bc in 10/11 ( Fig. 5 A), edge wrinkled, surrounded by white, swollen skin. Female pores tiny holes, one pair on anterior-most border of XII, each pore in line with seta b. Genital markings absent. Preserved specimen grayish or pale gray.

Internal: Septa 5/6–8/9 thick and muscular, 9/10 thin. Gizzards three in XII–XIV, round, white, muscular and shining. Hearts four pairs in VI–IX. Nephridia holoic. Testis sacs one pair, large, yellowish, oval, each suspended on septum 9/10, about 1.4 mm in length and 1.6 mm in width. Sperm duct long, in a cluster of densely coiled loops, loosely coiled while passing along the upper edge of the male atrium and entering the dorso-anterior end of the male atrium ( Fig. 5 B). Male atrium white, S- or C-shaped, its lower end in connection with coelomic surface of penis pouch. Ovarian chamber formed by septa 10/11 and 11/12, surrounding the esophagus in an inverted Ushape. One pair of follicular, yellowish ovisacs dorso-lateral on both sides of the digestive tract, extending posteriorly to segment XIV–XVI, moniliform or constricted by each septum. Spermathecae one pair, both ampulla and spermathecal atrium lying on posterior face of septum 7/8. Ampulla small, oval-shaped, about 0.6 mm long and 0.5 mm wide, its duct long, slender, coiled ( Fig. 5 B). Atrium small, oval-shaped, about 0.4 mm in length and 0.2 mm in width. Accessory glands absent.

DNA barcodes. GenBank accession numbers KJ782588 (MTS 148, holotype), KJ782585 (MTS 143, paratype), KJ782584 , KJ782586 , KJ782587 and KJ782589 (MTS 144, 145, 146 and 147, respectively).

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

Remarks. Drawida dongyinica sp. nov. is found on the islands of Dongyin and Hsiyin. It is indistinguishable from D. beiganica externally when penes of both species are wholly concealed, but is distinguishable from D. beiganica by having much smaller spermathecae with both ampulla and spermathecal atrium confined in segment VIII, and gizzards in XII–XIV. Molecular analyses also show that D. dongyinica and D. beiganica are genetically different with 14.3%–17.2% genetic distances between any pair of individuals of the two species ( Table 3 ). Drawida dongyinica also resembles Drawida moriokaensis Ohfuchi, 1938 from Japan. Both species have small ampulla, small spermathecal atrium and no genital markings ( Ohfuchi 1938). However, D. moriokaensis has ampulla on posterior while spermathecal atrium on anterior face of septum 7/8, and two or three gizzards in X–XIII ( Ohfuchi 1938).

Drawida dongyinica is also similar to D. eda in body size and in the absence of genital markings. The two species are easily distinguishable by the large spermathecal atrium, much shorter sperm ducts, and five gizzards in XIII–XVII of D. eda ( Blakemore & Kupriyanova 2010) .

Figures

FIGURE 5. Drawida dongyinica sp. nov. Holotype (TESRI-O-H- 46). A. Ventral view of spermathecal and male pore region (sp, spermathecal pore; mp, male porophore). B. Dorsal view of left spermatheca (amp, ampulla; sa, spermathecal atrium), testis sac (ts), sperm duct (sd), and male atrium (ma). Scale bars = 1 mm.