Drawida vazhania Ardra & Narayanan, sp. nov.

Type material. Holotype: Clitellate (ZSIK Reg. No. ZSI/WGRC/I.R.INV.30544), Vazhani Dam site in Peechi-Vazhani Wildlife Sanctuary (10.6347°N 76.3058°E), ca. 8 km southeast of Wadakkanchery, and about 24 km northeast of Thrissur town centre, Thrissur District, Kerala State, India, 47 m a.s.l., open garden area with trees, collected from beneath a Mangifera indica tree, 5 November 2024, leg. Rajendran Menon Ardra. Paratypes: 5 clitellates (ZSIK Reg. No. ZSI/WGRC/I.R.INV.30545), same collection data as for holotype.

Other materials. 9 clitellates and 1 adult aclitellate (ACESSD/EW/2047), same collection data as for holotype; 3 clitellates, 1 adult aclitellate (ACESSD/EW/2048), 31 July 2025, rest same data as for the holotype; 2 clitellates, 8 adult aclitellates (CATE-WG, EW/151), 31 July 2025, rest same data as for the holotype.

Diagnosis. Drawida vazhania sp. nov., is a member of the Barwelli species-group. Dimensions: length 21–39 mm, width 2.5–4.5 mm, segments 106–146. Setae present from segment 2. Dorsal pores absent. Clitellum annular, indistinct on segment ½9–½14 (= 5). Spermathecal apertures paired, aligned at setal line c. Secondary male apertures in small transverse round to oval depression, at BC setal lines; male pores minute, on tips of short tubular penes, usually wholly concealed within aperture in retracted condition. Male field surround with several whitened, irregular-shaped genital tumescence, groove like margins present between epidermal thickenings, a distinct longitudinal groove extends full length of segment 10. Gizzards three to four, within segments 12–16. Vas deferens, enters middle glandular portion of prostate directly at posterior side. Prostates paired, glandular, kidney shaped, bend on itself at its junction with dome-shaped muscular prostatic duct (penial chamber); prostatic capsule, narrow, round tubular, C-shaped. Spermathecal atrium, small, sessile on body wall, about oval-shaped, longitudinally placed, confined to segment 7; duct joins atrium in its posterior side. It can easily be differentiated from the congeners of the Barwelli species-group by the combination of the characters such as, irregular-shaped genital tumescences with grooves at male field, kidney-like prostate; narrow, long, round tubular, C-shaped prostatic capsule and the type of spermathecal atrium, which is small, sessile on body wall, about round to oval-shaped, longitudinally placed.

Description. External: Colour light grey dorsum, whitish ventrum in preservation. Body circular in cross section, with slight lateral thickening. Dimensions: Holotype: length 36 mm, width 3.5 mm at segment 9, segments 146; paratypes: length 21–36 mm, width 2.5–2.8 mm, segments 106–137; other materials: length 22–39 mm, width 2.9–4.5 mm, segments 109–140. Setae lumbricine, minute, closely paired, present from segment 2; setal formula aa: ab: bc: cd: dd = 10:2:10:1:43 and 8:1:8:1:27.5 at segment 8; aa: ab: bc: cd: dd = 10:2:13:1:44 and 19:2.5:19.5:1:68 at segment 20 (n = 2). Prostomium prolobous. Dorsal pores absent. Clitellum annular, indistinct on segment ½9–½14 (= 5), light yellowish in preservation, intersegmental furrows distinct, setae visible (Fig. 1A, B). Spermathecal apertures paired, at intersegmental furrow 7/8, aligned at c setal line, puckered epidermal thickenings present in front and back of spermathecal apertures in segments 7 and 8. Secondary male apertures paired, in small transverse round to oval depression, in intersegmental furrow 10/11, situated in BC setal lines (Fig. 1A, B, C); male pores minute, on tips of short tubular penes (Fig. 1D), eversible from parietal invaginations, usually wholly concealed within aperture in retracted condition (Fig. 1C). Female pores paired, minute, in intersegmental furrow 11/12, in b setal line. Nephridiopores visible from intersegmental furrow 6/7, in single line at d. Several whitened, irregular-shaped genital tumescence of epidermal thickenings, surround secondary male apertures in segments 10 and 11, together a flower-like impression, groove like margins present between epidermal thickenings (Fig. 1A, B), a distinct longitudinal groove extends full length of segment 10, from posterior intersegmental furrow 9/10 to secondary male aperture area in 10/11 (Fig. 1B); a pair of thin transverse depression or groove present in setal arc between BC setal lines in segment 11 (Fig. 1C).

Internal: Brownish pigmentation in circular muscle layer. Septa 5/6/7/8/9 thickly muscular. Gizzards three to four, within segments 12–16, constantly present on segment 14 and 15; intestine origin in segment 20±1. Last pair of hearts in segment 9; commissures of extra oesophageal vessels on the posterior face of septum 8/9 and 9/10 not recognizable. Testis sac paired, irregular shaped, smooth, confined to segments 9 and 10, constricted by septum 9/10; vas deferens, thin, very long, coiled to form a large mass, mass smaller than testis sac, entering prostate directly in the middle glandular portion of prostate at posterior side. Prostates paired, glandular (yellowish-white), kidney or bean-shaped, bend on itself at its junction with prostatic duct (penial chamber), generally bend anterio-laterally; prostatic capsule, narrow, long, round tubular, C-shaped, smooth; prostatic duct form a broad sessile hemispherical or dome-shaped muscular ectal end (penial chamber), about one fifth of the combined length of duct plus gland. Spermathecal ampulla paired in segment 8, ampulla large, ovoid, often anterio-posteriorly flattened; spermathecal duct fairly short, thick with two or three loops; atrium distinct, small, sessile on body wall, about round to oval-shaped, longitudinally placed, confined to segment 7; duct fairly short, thick with a few coils on posterior face of septum 7/8, penetrates septum 7/8 close to the body wall, joins atrium in its posterior side. Ovarian chamber complete in segment 12; ovisacs paired, large, with irregular margins, wide ectally, tapering ental end, extends in segments 12–13. Nephridia avesiculate. Inner faces of genital tumescence lack accessory glands.

Variations. In one paratype material and many other materials penes are retracted and wholly concealed within secondary male apertures. In specimens with everted penes dome-shaped ectal penial chamber is not much pronounced than the specimens with retracted penes. In one other material specimen (ACESSD/EW/2048), everted penes are slightly angled posteriorly.

Etymology. The specific epithet ‘ vazhania’ is a toponym refers to the type locality ‘Vazhani’, a noun in genitive case. Vazhani is an integral portion of the Peechi–Vazhani Wildlife Sanctuary in Thrissur District of the state of Kerala in south-western India, from where this species was collected and described.

Ingesta. Colloids of fine mineralized yellowish soil (lateritic?) with small pieces of pebbles, mica etc.

Habitat. Collection site is an open area with grasses and widely separated trees. Common vegetation of this area is dominated by Axnopus compressus grasses, Mangfera indica and invasive Senna spectabilis trees. Soil of this region belongs to Kozhukully soil series, which is acidic and fine textures gravelly soils prone to excessive erosion (Premachandran 2007).

Biology. Two specimens (ACESSD/EW/2047) have regenerated segments at the posterior end (12 and 22 segments).

Ecology. Appears to be an endogeic species, as indicated by the pale colour and fine mineralized soil in the intestine.

Distribution. Endemic to India: Kerala State: Thrissur District: Vazhani in Peechi-Vazhani Wildlife Sanctuary (Fig. 3). Being a small species it can also be found in the adjacent areas of the Peechi-Vazhani Wildlife Sanctuary.

Remarks. Drawida vazhania sp. nov., belongs to the Barwelli species group. Species of this group are characterized by small body size, secondary male apertures situated in between BC setal lines, usually male pores are located on eversible penes, genital markings or genital tumescence present near male field, prostate glandular, distinct spermathecal atrium absent or present and internal accessory glands associated with genital markings/tumescence absent. Species belonging to Barwelli group are D. barwelli (Beddard, 1886), D. beddardii (Rosa, 1890), D. rara Gates, 1925, D. constricta Gates, 1929, D. spissata Gates, 1930, D. delicata Gates, 1962 and D. vazhania sp. nov. According to Gates (1972) D. delicata lacks genital markings, even though he stated that, epidermis is whitened in median portion of BC between equators of 10/11. It is somewhat similar to the epidermal thickenings present in Barwelli group; hence it is also included in this group. Blakemore & Kupriyanova (2010) opined that taxonomically key characteristics are often ambiguous for small Drawida species. But the new species can be separated from the small similar looking species of the Barwelli group by various unique features.

The new species D. vazhania sp. nov., can be easily separated from D. barwelli (Beddard, 1886) by the shape of the prostate (kidney-shaped vs cotton-like), prostatic capsule (narrow, round tubular, C-shaped vs digitiform) and condition of the spermathecal duct (fairly short, thick with two or three loops vs long, slender, coiled and contorted) and extension of ovisacs (in segment 12–13 vs in three to eight segments in 11–18). D. vazhania sp. nov., can easily differentiated from the D. beddardii by the presence or absence of dorsal pores, which is absent in D. vazhania sp. nov., whereas it is present in latter, apart from this, spermathecal duct is simple and almost straight in D. beddardii, whereas in the new species it is fairly short, thick, with a few coils. It can be differentiated from D. rara Gates, 1925 by the type of genital tumescence (irregular-shaped epidermal thickening, together a flower-like impression, with grooves, in 10 and 11 vs whitened epidermal thickenings in segments 7, 8, 9, 10 and 11), intestine origin (20±1 vs 23±1) and shape of prostate (kidney-shaped, dome-shaped muscular ectal end vs sessile, circular, discoidal to dome-shaped) etc. Intestine origin (20±1 vs 24, 25), joining position of vas deferens at prostate (middle portion vs ental end), prostatic capsule (narrow, round tubular, C-shaped vs club-shaped, narrowed ectally, bent), etc. differentiates D. vazhania sp. nov., from D. constricta. D. spissata is another related species, which is differentiated from D. vazhania sp. nov., by the following features such as body dimension (length: 90–130 mm; width: 5–7 mm vs length: 21–39 mm; width: 2.5–4.5 mm), additional genital markings in segment 8 (present vs absent), number and location of gizzards (four to five (in 17–21) vs three to four (in 12–16)), and type of prostate (very long coiled; capsule digitiform vs kidney-shaped; capsule tubular C-shaped); spermathecal atrium (absent vs present), etc. D. vazhania sp. nov., joining position of vas deferens at prostate is in the middle portion, prostate is kidney-shaped, dome-shaped muscular ectal end, prostatic capsule is narrow, round tubular, C-shaped. Whereas in D. delicata vas deferens joins prostate at its ectal end, prostate is erect, berry-shaped with fine duct, and the prostatic capsule is digitiform or club-shaped. Detailed comparison of the characteristics of the Barwelli group members are provided in Table 1.