Polypheretima taprobanae (Beddard, 1892)

Shen, Huei-Ping & Yeo, Darren C. J., 2005, Terrestrial Earthworms (Oligochaeta) From Singapore, Raffles Bulletin of Zoology 53 (1), pp. 13-33 : 27-28

Polypheretima taprobanae (Beddard, 1892)

( Fig. 5 )

Perichaeta taprobanae Beddard, 1892a: 163 .

Perichaeta pauli Michaelsen, 1897: 243 .

Amyntas taprobanae – Beddard, 1900a: 648.

Pheretima taprobanae – Michaelsen, 1900: 308; Gates, 1972: 220.

Pheretima taprobanae var. pauli – Michaelsen, 1900: 309.

Metapheretima taprobanae – Sims & Easton, 1972: 233.

Metapheretima pauli – Sims & Easton, 1972: 233.

Polypheretima taprobanae – Easton, 1979: 45; 1982: 734; 1984: 117.

Material examined. – 1 mature (clitellate) specimen (dissected)( ZRC), under a fallen log in the Singapore Botanic Gardens Jungle, coll. K. K. P. Lim & K. L. Yeo, 11 Mar.2003.

Description. – Stout worm, length 105 mm, weight 1.61 g. Segments numbering 122. Prostomium prolobous. First dorsal pore 12/13. Three annulets per segment from segment VI. Setae minute, closely spaced, not easily visible. Setal number 55 in V, 85 in VII, 82 in XII, 77 in XX, 71 in XXV, 14 between male pores in XVIII. Clitellum XIV-XVI, 3.5 mm in length, 5.11 mm in width, dorsal pores absent, three setal rings with setal number 63 in XIV, at least 55 in XV, 61 in XVI, pale in colour with an amorphous appearance. Spermathecal pores one pair in 7/8, ventro-lateral, each on a papilla-like porophore in the segmental furrow ( Fig. 5A ), distance between paired pores 0.34 body circumferences ventrally apart. Female pore single, medio-ventral in XIV. Male pores paired in XVIII, about 0.29 body circumferences ventrally apart, male aperture not visible; porophore round, white in color, indistinctly demarcated, about 0.5 mm in diameter ( Fig. 5B ). A white, indistinctly demarcated circular area immediately posterior to each male porophore in presetal annulet of XIX. Genital papillae absent in both preclitellar and postclitellar regions. Preserved specimen pale greyish on dorsum, light grey on ventrum, pale grey on clitellum, and white in the anterior five segments.

Septa 5/6-7/8 and 12/13/14 thickened, 8/9 membranous, 9/ 10 absent, 10/11/12 thin. Gizzard large in IX-X, yellowish white. Intestine enlarged from XIV. Caeca absent. Esophageal hearts XI-XII. Meronephridia bush-like mass in intersegmental spaces anterior to 6/7. Spermathecae one pair in VIII, small, ampulla oval, slightly wrinkled, about 0.6 mm long, 0.38 mm wide, with a stout stalk of about 0.57 mm long ( Fig. 5C ). Diverticulum transparent, stalk enlarged at proximal end and narrow, slender, twist at distal end with an oval seminal chamber of about 0.35 mm in length. Holandry: testis sacs in X and XI, annular, smooth, pink. Seminal vesicles paired in XI and XII, small, follicular, yellowish, first pair included in testis sacs. Prostate glands small, paired in XVIII, racemose, follicular, yellowish white ( Fig. 5D ). Prostatic ducts large, stout, looped ( Fig. 5E ), passing into the parietes in the posterior portion of XVIII. Accessory glands absent.

Remarks. – Polypheretima taprobanae is a holandric and bithecal earthworm belonging to the bifaria species-group of the genus Polypheretima (sensu Easton, 1979) . This species is known mostly from botanical gardens in India, Ceylon, Brazil, Hawaii ( Gates, 1972); Madagascar ( Michaelsen, 1897); Northeast Australia, Fiji, and Seychelles ( Easton, 1979, 1984). It has never been recorded from the Pheretima domain ( Gates, 1970). Gates (1972) postulated its original home perhaps to be New Guinea. However, the numerical studies by Easton (1979) suggested that the species might have originated in Southeast Asia.

ORDER MONILIGASTRIDA

FAMILY MONILIGASTRIDAE

Figures

Fig. 5. Polypheretima taprobanae (Beddard, 1892). A, left lateral view of spermathecal region (sp, spermathecal porophore); B, ventral view of male porophore (mp) region; C, dorsal view of right spermatheca (amp, ampulla; dv, diverticulum); D, dorsal view of right prostate gland; E, right prostatic duct.