Drawida impertusa Stephenson, 1920

Blakemore, Robert J., Lee, Seunghan & Seo, Hong-Yul, 2014, Reports of Drawida (Oligochaeta: Moniligastridae) from far East Asia, Journal of Species Research 3 (2), pp. 127-166 : 137-138

4. Drawida impertusa Stephenson, 1920

Drawida barwelli var. impertusus (sic) Stephenson, 1920: 200. [ From Bombay. Types ZSIC Calcutta 301, BMNH 1925:5:12:77].

Drawida barwelli var. impertusa : Stephenson, 1923: 134; 1930.

? Drawida sp. 2 Gates, 1943: 90 (three juvenile specimens from Manila).

Drawida impertusa : Gates, 1965: 87; 1982: 18; Blakemore, 2008, 2012b.

Distribution. India, originally Bombay but now recogniz- ed more widely, e.g. in Bangalore, Coimbatore and, significantly, reported from four sites in the Philippines, (?at Calayan Island far northern Philippines, possibly found along with 33 specimens of D. bahamensis from bank of small river, 23 rd Oct., 1903 by McGregor of US Natl. Mus. Division of “Marine Invertebrates” Number 28710, or at Manila and elsewhere).

Material examined. “ S21” (mature, dissected that provided DNA sample P8) longest in batch of four specimens from Kahariam farm at Lipa City , Batangas, Luzon , Philippines, collected from rice paddy near entrance gate 14 th Nov., 2013 by RJB and Rowena Ocenar ; a shorter specimen in same “S21” jar; “S8” two larger mature specimens from Kahariam farm collected from rice paddy near entrance gate 13 th May , 2013 by RJB (one dissected). Specimens : one mature in sample “S18” with Metaphire bahli , from Kahariam farm beside rice at gym collected 14 th November , 2013 by RJB and RO; plus several unregistered specimens from Lipa providing DNA samples (W1, W6, W13, W14, W15, W17) that were unsuccessful due to delay as noted in Appendix. Specimens “P6” and “P7” two mature specimens (P6 an anterior amputee) from Penalosa farm at Hacienda Remedios , Victorias City , Negros, Visayas providing DNA samples P~6 and P~7, respectively, that differ somewhat ( Fig. 1, Appendix) .

Description. (From Stephenson, 1920; 1923 and pers. obs.). Size 45-90 mm (45-48 mm Stephenson or to 75 mm Gates, 1943) by 2.5-3.5 mm. Segments, 165 current (130- 132 Stephenson). Colour a blotchy olive, darker dorsally with still darker mid-D line; or unigmented ( Gates, 1943 and current). Prostomium prolobous. Clitellum 9-13 (current). Dorsal pores absent, indicated in some specimens as small pale dots, but no perforations. Setae aa less than bc except at hind end; Gates’ (1943: 90) specimens often lacked anterior setae to segment 10, thus are similar to D. zhangetalia Blakemore, 2006 . Nephropores in row below level of c lines. Male pores in 10/ 11 in mid-bc; bounded fore and aft by prominent lips; with a pair of indefinite but fairly large whitish papillae in segment in front of the male pores [those described by Gates, 1943 from Manila nearly reach from 9/10 to 10/11 and are elliptical, plus male field is depressed anterior and posterior to the male pore just as seen in current Lipa specimens]. Spermathecal pores in 7/8 below c lines. Female pores in 11/ 12 in b lines. Clitellum 9,10-13.

Gizzards typically four in 14-17 or perhaps five in 13, 14-17 (or sometimes three as Gates, 1943 has 12-14, 14- 17 and 15-17 in his three Manila specimens; current specimens four in 13-16 or three in either 14-16 or 15-17]. Prostates flat, sessile, almost circular and “furry” glandular (not noted in current specimens cf. pear-shaped in D. barwelli ). [Vas deferens loops to side of prostate and there are no spermathecal atria - Gates, 1943; or atrium small in current specimens from short, coiled duct]. Ovarian chamber present, annular in 11, ovisacs present, extending back to 13,14,15. Otherwise as D. barwelli according to Stephenson’s (1920) account.

Remarks. Similar to Stephenson’s concept of D. barwelli but with a pair of fairly large whitish papillae on the segment in front of the male pores in 10, and gizzards often in 14-17 and, most distinctively, lack of dorsal pores unlike D. barwelli proper. In fact Stephenson said that the specific name alluded to this lack of pores. It is also similar somewhat to D. bournei (Michaelsen, 1897: 167) that Stephenson (1920: 202) says Michaelsen thought was itself a variety of D. pellucida (Bourne, 1894: 13) ; but they are easily separable on the form of the prostates. The prostates are flat, sessile, almost circular and ‘furry’ in D. impertusa cf. pear-shaped in D. barwelli and “ longitudinally ellipsoid body sessile on the parietes ” ( Gates, 1943) in D. bournei .

Resolution now depends on obtaining DNA from topotypic Bombay material that may yield data the same as either current haplotype. Apparently a variable species, with regard to gizzard location, that is somewhat similar to D. barwelli although there is no match on Genbank and with the current “ Drawida barwelli ” specimens. Both D. japonica and D. impertusa are said to have GMs in segment 10 but these are round and intermittent in D. japonica but distinctively large, elongated and regular in D. impertusa . Current specimens are not close genetically to any tested congeners ( Fig. 1, Appendix).

Only three Drawida species were hitherto reported from the Philippines: type-species Drawida barwelli was originally found at Manila, and Gates (1965, 1982) recorded both D. impertusa and D. bahamensis . However D. bahamensis is usually included with D. barwelli and perhaps Gates’ only reason to separate it was his assertion that D. barwelli was poorly known. Neither of the two previously Philippine species were reported from rice paddy although Drawida spp. are known from rice in Japan, Korea and India thus presumably tolerating periodic inundation.