Moniligaster keralensis Narayanan & Sathrumithra & Anuja & Christopher & Thomas & Julka 2021, sp. nov.

Moniligaster keralensis Narayanan & Julka, sp. nov.

(Figure 3)

Type material. Holotype: Clitellate (ZSI/ WGRC / IR /INV/8839), evergreen forest, Kurichikanam in Konni Reserve Forest (9°12'17.8"N, 77°00'36.3"E) (10 km from Kokkathodu), Pathanamthitta District, Kerala, India, 03 May 2015, 534 m a.s.l., S. Sathrumithra, J.K. Joseph and A. Sasi. Paratypes: 4 clitellates (ZSI/ WGRC / IR /INV/8840), collection data as for holotype.

Other material. 41 specimens altogether. 3 clitellates (ACESSD /EW/729), Elettaria cardamomum and Piper nigrum plantation, Chathurangappara in Cardamom Hill Reserve (9°53’46.8”N, 77°13 5.3”E), Idukki District, Kerala, India, 12 January 2011, 1105 m a.s.l., S.P. Narayanan; 1 clitellate and 7 aclitellates (ACESSD /EW/730), evergreen forest, Aluvamkudy (9°16'7.8"N, 77°00'16.8"E), Pathanamthitta District, Kerala, India, 21 August 2013, 513 m a.s.l., S.P. Narayanan, S. Sathrumithra, D. Kuriakose and A. Sasi; 1 clitellate and 6 aclitellates (ACESSD / EW/731), riparian stretch, Mundomoozhy (9°14'43.8"N, 76°55'20.1"E), Pathanamthitta District, Kerala, India, 21 August 2013, 68 m a.s.l., S.P. Narayanan, S. Sathrumithra, D. Kuriakose and A. Sasi; 4 aclitellates (ACESSD / EW/732), evergreen forest, Kottavasal in Achankovil Reserve Forest (9°4'17.4"N, 77°12'24.5"E), Kollam District, Kerala, India, 22 August 2013, 474 m a.s.l., S.P. Narayanan, T. Augustine, A. Sasi, S. Sathrumithra and D. Kuriakose; 1 clitellate (ACESSD /EW/733), evergreen forest, near to Ambanad estate in Achankovil Reserve Forest (9°02'26.4"N, 77°07'06.3"E), Kollam District, Kerala, India, 24 August 2013, 795 m a.s.l., S.P. Narayanan, D. Kuriakose, S. Sathrumithra, T. Augustine and A. Sasi; 1 clitellate (ACESSD /EW/734), mixed crop area, Peruvanthanam (9°33'55.3"N, 76°56'7.7"E), Idukki District, Kerala, India, 22 July 2014, 213 m a.s.l., J.K. Joseph; 1 clitellate and 4 aclitellates (ACESSD /EW/735), semi evergreen forest, Thannithodumoozhy in Konni Reserve Forest (9°15'19.0"N, 76°55'36.4"E), Kollam District, Kerala, India, 10 June 2016, 94 m a.s.l., S. Sathrumithra; 1 clitellate and 4 aclitellates (ACESSD /EW/736), Tectona grandis plantation, Pananthodu in Konni Reserve Forest (9°13’37.4”N, 76°55’26.8”E), Pathanamthitta District, Kerala, India, 10 July 2016, 105 m a.s.l., S. Sathrumithra; 1 clitellate and 6 aclitellates (ACESSD /EW/737), Hevea brasiliensis plantation, Chengara (9°15’2.1”N, 76°51’54”E), Pathanamthitta District, Kerala, India, 23 August 2016, 88 m a.s.l., S. Sathrumithra.

Diagnosis. Colour bluish. Length 71–129 mm, diameter 4–5.5 mm, segments 109–195. Secondary male apertures paired, large transverse slits, slightly lateral to b setal lines, at intersegmental furrow 10/11. Spermathecal pores paired, small transverse slits, close to cd setal lines, at intersegmental furrow 7/8. Genital markings absent. Gizzards four in segments 14–19. Vas deferens a mass of hairpin loops, mass as large as testis sac, entering prostate directly, near the ectal end. Prostates glandular, tubular with irregular margins, slightly flattened, prostatic capsule tubular, prostatic duct bent downwards and narrowed. Spermathecal atrial glands bilobed in segment 7, glands bound together, duct of each gland about as long as the common atrial duct.

Description. External: Colour bluish; body circular in cross section. Dimensions: Holotype: 71 mm by 4.5 mm at segment 9, segments 109; paratypes: 82–89 mm by 4–5 mm at segment 9, segments 135–149; other materials: 92–129 mm by 4.5–5.5 mm at segment 9, segments 166–195. Setae lumbricine, closely paired, present from segment 2; setal formula aa = 7–8.75 ab = 1.08–1.46 bc = 9.33–11.67 cd = 0.2–0.27 dd at segment 8, aa = 6.2–8.75 ab = 0.91–1 bc = 7.75–11.67 cd = 0.31–0.44 dd at segment 20 (n=3). Clitellum annular, on segments 10–13, intersegmental furrows distinct, colour reddish. Spermathecal pores small transverse slits, aligned between setae cd, at intersegmental furrow 7/8. Male pores paired, minute, at the centre of short, eversible penes, secondary male apertures oval-shaped at intersegmental furrow 10/11 (Fig. 3A). Female pores paired, minute, at intersegmental furrow 11/12, slightly median to b setal lines. Nephridiopores minute, present from segment 3, aligned with d setal lines. Genital markings absent.

Internal: Septum 5/6 slightly muscular, septa 6/7/8/9 muscular, septum 9/10 delicate. Gizzards four in segments 14–19; intestinal origin in segments 27–29. Commissures of extra-oesophageal vessels present on posterior faces of septa 8/9 and 9/10. Testis sacs paired, in segments 9–11 on one side and dislocated to segments 13–14 on the other side but retaining connection with septum 9/10 through a narrow tube like membranous structure; vas deferens in segments 9–10, coiled into a mass of hairpin loops, mass as large as testis sac, entering near the ectal end of the prostate gland directly without entering musculature. Prostates paired, extending from segment 11 to segments 13–14, glandular, tubular and somewhat flattened with irregular margins (Fig. 3B); capsule tubular, slightly enlarged ectally before its junction with prostatic duct (Fig. 3C); prostatic duct bent downwards, narrowed and slightly muscular, much shorter than gland, about one ninth of the combined length of the gland and duct. Spermathecae paired in segment 8, ampulla elongate-ovoidal, each with a long coiled duct penetrating septum 7/8 to discharge at junction of ducts of dichotomous atrial glands in segment 7; atrial glands bound together with one on top of the other (Fig. 3D), duct of each gland, almost as long as the common atrial duct. Ovarian chamber complete, ovisacs in segments 12–16. Nephridia avesiculate; functional at segment 10.

Etymology. The specific epithet ‘ keralensis’ is derived from the name of the Indian state of Kerala, where this species was collected.

Ingesta. Colloid of fine soil (silt) with tiny pieces of quartz and brown organic particles.

Habitat. Evergreen and semi-evergreen forests and plantations of cardamom, black pepper, teak and rubber.

Biology. The species shows serpentine movement when disturbed. Autotomy and regeneration of lost parts appear to be common.

Distribution. India: Kerala State: widespread in the middle and higher altitude regions of Idukki District: Chathurangappara, Peruvanthanam; Pathanamthitta District: Aluvamkudy, Chengara, Kurichikanam, Mundomoozhy, Pananthodu, Thannithodumoozhy; and Kollam District: Kottavasal, near to Ambanad estate (Fig. 4).

Remarks. Moniligaster keralensis sp. nov. belongs to the same group of species as M. bahli sp. nov. (see remarks there) and M. blakemorei sp. nov.. The species are compared in Table 1. Differences of M. keralensis sp. nov. to other species of the group are as follows: M. keralensis sp. nov. is distinguished from M. gravelyi by the junction of vas deferens with the prostate glands at ectal rather than at ental end and intestinal origin (in segments 27–29 vs segment 25). M. keralensis sp. nov. differs from M. troyi in the shape of the prostate glands (tubular vs club-shaped), body dimensions (length 71–129 mm vs 60–63 mm; diameter 4–5.5 mm vs 3.5–3.7 mm), junction of vas deferens with the prostate glands (at ectal end vs about middle) and length of atrial gland duct (almost as long as common atrial duct vs about one fourth the length of common atrial duct). For differences of M. bahli sp. nov. and M. blakemorei sp. nov., see the remarks sections of these species.