Megascolex jeyporeghatiensis Narayanan & Paliwal, 2024

Naik, Ayusmita, Narayanan, S. Prasanth, Palita, Sharat Kumar, Thomas, A. P. & Paliwal, R., 2024, Two new species of the genus Megascolex Templeton, 1844 (Clitellata, Megascolecidae) from the Eastern Ghats of Odisha state, India, Zootaxa 5424 (5), pp. 569-580 : 573-575

publication ID	https://doi.org/10.11646/zootaxa.5424.5.5
publication LSID	lsid:zoobank.org:pub:408B8477-FA34-4FCF-B041-D6BF9A194315
DOI	https://doi.org/10.5281/zenodo.14931598
persistent identifier	https://treatment.plazi.org/id/03CACC79-6D37-C031-FF43-FF6D11EEF856
treatment provided by	Plazi
scientific name	Megascolex jeyporeghatiensis Narayanan & Paliwal
status	sp. nov.

Treatment

Megascolex jeyporeghatiensis Narayanan & Paliwal View in CoL , sp. nov.

( Figure 2 View FIGURE 2 )

Type material. Holotype: Clitellate ( ZSIK Reg. No. ZSI/ WGRC /I. R.INV. 25144), Jeypore Ghati (18.83929°N, 82.61730°E), around 10 km away from Jeypore town , Koraput District, Odisha State, India, 862 m a.s.l., moist deciduous forest, collected from beneath the leaf litter in a bed of pebbly soil along with roots of Pteridophyte ( Athyrium sp. ), around 10 m from a non-perennial stream, 5 June 2022, collected by A. Naik. GoogleMaps Paratypes: 3 pre-adults ( ZSIK Reg. No. ZSI/ WGRC /I. R.INV. 25145), Rani Duduma (18.70984°N, 82.94966°), around 25 km away from Semiliguda town, Koraput District, Odisha State, India, 930 m a.s.l., near stream in dry deciduous forest, 20 October 2021, collected by A. Naik.

Other material. 1 pre-adult, 6 juveniles (ACESSD/EW/1637) same collection data as for paratypes .

Diagnosis. Large sized; length 221–281 mm, width 8–10 mm at segment 10, 168–189 segments. Prostomium proepilobic or closed epilobic, with conspicuous canalicula. Clitellum, annular, on segments ½13, 13, 14–18, ½19, 19 (= 6½–7), indicated by dark colouration than rest of the body, otherwise not well-marked in pre-adults, setal arc visible. Quadrithecal, spermathecal pores large, circular, in intersegmental furrows 7/8/9. Male field pale coloured, male pores paired widely paired, on a raised papilla, porophores minute, at centre in a tubercle, on segment 18, setae absent between male pores. Genital markings present, two pairs, transversely elliptical depression, with elevated edge, each depression is divided by a longitudinal dyke at the mid-ventral line, markings confined to segments 17 and 19. Penial setae absent. Gizzard large, muscular, barrel-shaped, in segment 6, septa 6/7/8/9 pushed posteriorly in funnel-like manner, and occupies segments 6–9. Oesophagus and gizzard are attached to parietes with several crisscrossed muscular fibres, which traverse through many septa; intestine origin in segment 16. Last pair of hearts in segment 13. Holandric. Prostates small, thickly racemose, fan-like, somewhat dorsoventrally flattened, incised, confined to segment 18, duct straight, transversely directed, ental portion branched, duct and prostate has fairly equal length. Spermathecae, presetal, sac-ilke, circular on segment 8, and lightly ovoidal on segment 9, ampulla and duct sharply marked off, ampulla lightly longer than duct, duct width about the ½ the size that of ampulla, single ectal diverticulum, diverticulum stalked, like a bulging in duct, placed at lateral face of the duct.

Description. External: Bluish, dorsum dark, pale at ventral side; body circular in cross section. Dimensions: Holotype: 253 mm, width 8 mm at segment 10, 169 segments; paratypes: 221–281 mm, width 8.5–10 mm at segment 10, 168–188 segments; other material: 240 mm, width 8 mm, segments 189. Prostomium proepilobic or closed epilobic, with conspicuous canalicula (mid-dorsal groove). Segments 7, 8, 9, 10 single annulated. First dorsal pore at intersegmental furrow 5/6, pores of segments 5/6/7 concealed in furrow, visible from 7/8 onwards. Clitellum annular, faintly demarcated by brownish colour, on segments ½13, 13, 14–18, ½19, 19 (= 6½–7), intersegmental furrows distinct, setal arc visible, dorsal pores occluded, pale whitish at male field. Setae perichaetine throughout, fairly large; setal formula aa = 2.5–3 ab = 2.5–4 bc = 1.67–3 yz = 0.71–1.25 zz on segment 12, aa = 1.75–2.25 ab = 2–3.6 bc = 1.4–2.25 yz = 0.67–1.28 zz on segment 24 (n = 2); 58–64 on segment 5, 64–80 on segment 9, 62–82 on segment 12, 64–86 on segment 20, 62–84 on segment 25 (n = 3); 14–16 between spermathecal pores lines on segment 7, setae absent between male pores. Male field pale coloured, male pores widely paired, on a raised papilla with 1–2 circular folds at base, porophores minute, at centre in a tubercle, on segment 18 in line with fg or gh setae, setae absent between male pores ( Fig. 2A View FIGURE 2 ), 0.3–0.33 body circumference apart (n = 2). In pre-adult specimens raised papilla is absent ( Fig. 2B View FIGURE 2 ). Female pores paired, minute in small transverse slits, presetal, at a or slightly lateral to a setal lines, on segment 14 ( Fig. 2A View FIGURE 2 ). Spermathecal pores paired, large, circular pores, in intersegmental furrows 7/8/9, in line with setae hi or ij, 0.3–0.32 body circumference apart (n = 2). Nephridiopores inconspicuous. Genital markings present, two pairs, transversely elliptical depression, with elevated edge, each depression is divided by a longitudinal dyke at the mid-ventral line, markings confined to segments 17 and 19 ( Fig. 2A View FIGURE 2 ). Pre-adult specimens, initiation of genital markings is present on intersegmental furrows 17/18 and 18/19 ( Fig. 2B View FIGURE 2 ). Penial setae absent.

Internal: Pigmentation brownish.Septa 4/5 strongly muscular, 5/6/7 aborted or with fine transparent membranous, 7/8/9 membranous, 9/10/11/12 thickly muscular, 12/13/14/15 slightly muscular. Oesophagus with large, barrel-shaped muscular gizzard, in front of septa 6/7, septa 6/7/8/9 pushed posteriorly in funnel-like manner, and occupies segments 6–9; oesophagus and gizzard are attached to parietes with several crisscrossed muscular fibres, which traverse through many septa; calciferous gland like swelling present in oesophagus with internal ridges in segments 12, 13, 14; intestine origin in segment 16; intestinal caeca absent, typhlosole present, lamelliform, simple, slightly raised ridge-like. Dorsal blood vessel single, complete, running in front of septa 4/5; supra-esophageal vessel present, single. Last pair of hearts in segment 13. Appears to be holandric; testes and funnels not distinguishable; seminal vesicles two pairs, small sac-like, in segments 9 and 12. Prostates paired, small, thickly racemose, fan-like, somewhat dorsoventrally flattened, slightly incised, confined to segment 18, duct thick, straight, transversely directed, ental portion branched, duct and prostate has fairly equal length ( Fig. 2C, D View FIGURE 2 ). Whereas in pre-adult specimens, prostates are thin, dorsoventrally flattened, duct with light muscular shimmer, duct equal or slightly longer than the length of prostate ( Fig. 2E View FIGURE 2 ). Spermathecae, two pairs, small, presetal, close to anterior margins in segments 8 and 9, ampulla sac-ilke, circular on segment 8, and lightly ovoidal on segment 9, ampulla and duct well marked off, ampulla lightly longer than duct, duct width about the ½ the size that of ampulla, single ectal diverticulum, diverticulum stalked like a bulging in duct, placed at lateral face of the duct ( Fig. 2F, G View FIGURE 2 ). In pre-adult specimens spermathecae dorsoventrally flattened, strap-like or tongue-like, pair on segment 8 directed longitudinally to posterior, pair on segment 9 towards posterior but diagonally directed towards lateral side, ampulla and duct not well marked off, ampulla and duct more or less of same length, duct width about same as that of ampulla ( Fig. 2H View FIGURE 2 ). Nephridia exonephric, astomate micromeronephridia, scattered randomly on parietes in clitellar segments, behind clitellar segments organized as bands in anterior and posterior regions of each segment near septum.

Etymology. The specific epithet ‘ jeyporeghatiensis’ is a toponym, named after the type locality—Jeypore Ghati of Koraput District, Odisha.

Ingesta. Large amount of gravely soil, with pebbles, rocks, organic materials like barks, leaf portions etc.

Habitat. Deciduous and moist deciduous forests in hilly terrain. As per Champion & Seth (1968) this region has two major forest types, namely tropical dry deciduous and tropical moist deciduous forests. Jeypore Ghati have moist deciduous forest with large rocks, boulders and soil with fine-loamy texture. Type locality has a non-perennial stream and worms were extracted from beneath the leaf litter in a bed of pebbly soil along with roots of Pteridophyte ( Athyrium sp. ). Almost 90% of the vegetation of this area is dominated by Shorea robusta trees. Apart from this Terminalia tomentosa , Xylia xylocarpa , Pterocarpus marsupium , Anogeissus latifolia , Butea monosperma , Careya arborea , Casaeria tomentosa , Lannea coromandelica, Helicteres isora, Holarrhena pubescens , Curcuma aromatica , Clerodendron infortunatum , Thysanolaena maxima, Cyonodon dactylon, Imperata arundinaceae , Arundinella setosa , Oxytenanthera monostigma etc. were found in the site. Whereas, Rani Duduma has dry deciduous forest and the soil is gravely-loamy with rocks and boulders. Common vegetation of this area is dominated by trees, shrubs and climbers such as Terminalia tomentos a, Shorea robusta , Boswellia serrata , Anogeissus latifolia , Pterocarpus marsupium , Dalbergia latifolia , Emblica officinalis , Cassia fistula , Bridellia retusa , Woodfordia fruticosa , Zizyphus oenopli a, Diospyros tomentosa, Lantana camara, Smilax macrophylla , Bauhinia vahlii , Butea superba etc.

Ecology. Appears to be an anecic species.

Distribution. Endemic to India: Odisha State: Koraput District: Jeypore Ghati and Rani Duduma ( Fig. 3 View FIGURE 3 ).

Remarks. Megascolex jeyporeghatiensis sp. nov. also belongs to the ratus group of species as M.quadripapillatus sp. nov. Differences of M. jeyporeghatiensis sp. nov. to other species of the group are as follows:

M. ratus has several pairs of genital markings, whereas M. jeyporeghatiensis sp. nov. has only two pairs of genital markings. In addition, M. jeyporeghatiensis sp. nov. can be further differentiated by the type of clitellum (annular vs saddle-shaped), intestinal origin (in segment 16 vs in segment 14), segmental location of prostate (confined to segment 18 vs occupy segments 19–22) etc. M. jeyporeghatiensis sp. nov. is differentiated from M. pumilio by large size (length 221–281 mm; diameter 8–10 mm; segments 168–189 vs length 54 mm; diameter 1 1/ 3 mm; segments 109), number of clitellar segments (in segments ½13, 13, 14–18, ½19, 19 (=6½–7) vs in segments 14–16 (=3)) etc. For differences from M. quadripapillatus sp. nov., see the remarks section of M. quadripapillatus sp. nov. Detailed comparison of the differences in the characters of these related species is provided in Table 1 View TABLE 1 .