Kanchuria priyasankari Narayanan, Paliwal & Julka, 2025

Narayanan, S. Prasanth, Paliwal, R., Kurien, Vijo T., Nath, Sabyasachi, Dey, Animesh, Nandy, Subhrajit, Kar, Prithwiraj, Goldar, Sujata, Thomas, A. P. & Julka, J. M., 2025, Description of two new Kanchuria Julka, 1988 (Clitellata: Megascolecidae) species of earthworms from Tripura State, North-eastern India, Zootaxa 5647 (2), pp. 101-116 : 107-110

Kanchuria priyasankari Narayanan, Paliwal & Julka , sp. nov.

( Figure 4A–D , 5A–D )

Type material. Holotype: Clitellate ( ZSIK Reg. No. ZSI/WGRC/I.R.INV. 28500), Kamalpur (24.1938° N, 91.8172° E), about 2 km southwest of Kamalpur town, Dhalai District, Tripura State, India, 64 m a.s.l., Hevea brasiliensis plantation, 11 September 2006, collected by Sabyasachi Nath. Paratypes: 5 clitellates ( ZSIK Reg. No. ZSI/WGRC/ I.R.INV. 28501), same collection data as for holotype .

Other materials. 26 clitellates ( ACESSD /EW/1771), same collection data as for holotype .

Diagnosis. Small-sized worm; length 44–73 mm, width (mid-clitellar) 2–2.5 mm, 78–207 segments. Clitellum annular on segments ¼13, 14–17 (= 4¼), dorsal pores occluded, intersegmental furrows indistinct, seta visible. Spermathecal pores 3 pairs, segmental, on the anterior margins of segments 7, 8 and 9, lightly extend into the anterior segment, between aa setal lines. Male field a central depression, surrounded by circular elevated margins, extends in post setal arc of segment 17 to presetal arc of segment 19, male pores minute, closely paired, on circular papillae, at anterior ends of seminal grooves, on mid-ventral line; seminal grooves paired, straight. Genital marking discrete, paired, median, postsetal, on segment 18, between bb setal lines, larger than male pore. Female pore single, minute, presetal, ventro-median. Intestine origin in segment 15. Metandric. Prostates paired, extend in segments 18–21, 22, 23, constricted by septa, prostatic duct slender, thin, sinuous, ectal end hemispherical, sessile on parietes. Spermathecae 3 pairs, on anterior margins, in segments 7, 8, 9, ampulla small, ovoid, ampulla and duct distinctly marked off; duct thin, sinuous, longer than ampulla or about same length; unidiverticulate, ectal diverticulum, diverticulum long tubular, stalk slender, comprehensively longer than duct plus ampulla. Genital markings glands absent.

Description. External. Pale, light rosy greyish (in preservation); body circular in cross section. Dimensions: Holotype: length: 62 mm, width (mid-clitellar): 2 mm, 152 segments; paratypes: length: 48–72 mm, width (mid-clitellar): 2–2.5 mm, 78–179 segments; other materials: length: 44–73 mm, width (mid-clitellar): 2 mm, 93–207 segments. Prostomium prolobic, retracted. First dorsal pore at intersegmental furrow 11/12. Setae lumbricine, widely separated anterior to clitellum, closely paired behind clitellum, present on segment 2; setal formula aa = 1.55–2.12 ab = 0.87–1.13 bc = 1.08–1.54 cd = 0.22–0.23 dd at segment 12 and aa = 2.86–3.5 ab = 1.33–1.4 bc = 1.75–2 cd = 0.22–0.33 dd at segment 24 (n = 2). Clitellum tumescent, annular on segments ¼13, 14–17 (= 4¼), colour brownish red (in preservation), dorsal pores occluded, intersegmental furrows indistinct, seta visible. Spermathecal pores 3 pairs, segmental, on anterior margins of segments 7, 8, 9, lightly extends into anterior segment, thus appears in intersegmental furrows 6/7/8/9, between aa setal lines ( Fig. 4A–B ). Male field a central depression, with circular elevated margins, extends in post setal arc of segment 17 to presetal arc of segment 19, male pores minute, closely paired, presetal on segment 18, on circular papillae, at anterior ends of seminal grooves, on mid-ventral zone, between aa setal lines; seminal grooves paired, straight to paired genital markings ( Fig. 4C–D ). Female pore single, minute, in a whitish transversely oval to circular area, presetal, ventro-median, at aa setal lines, on segment 14 ( Fig. 4C–D ). Genital marking discrete, paired, median, postsetal, somewhat oval-shaped, longitudinally placed, on segment 18, between bb setal lines, with central aperture, larger than male pore ( Fig. 4D ). Nehridiopores not recognizable. Penial setae absent.

Internal. Unpigmented. Septum 5/6 delicate, septa 6/7–11/12 muscular. Oesophagus with large, muscular, barrel-shaped gizzard, in segment 5 (between septa 4/5 and 5/6), septa 6/7/8 pushed posteriorly in funnel-like manner, take the space of segments 6–8; calciferous glands on segments 12 and 13; intestine origin in segment 15; intestinal caeca absent; typhlosole simple, lamelliform. Dorsal blood vessel, single, complete. Last pair of hearts in segment 13. Metandric; testis and funnels, paired, free, in segment 11; seminal vesicles paired, racemose, in segment 12; ovaries paired in segment 13. Prostates paired in segment 18, racemose, strap-shaped, somewhat latero-medially flattened, thin, with incised margins, longitudinally placed ( Fig. 5A–B ), prostatic glands extend in segments 18–21, 22, 23, constricted by septa; prostatic duct slender, thin, lightly twisted, same width throughout, ectal end spheroidal, sessile on parietes ( Fig. 5B ), muscular shimmer present. Spermathecae 3 pairs, on anterior margins, in segments 7, 8, 9, ampulla small, ovoid, ampulla and duct distinctly marked off; duct thin, sinuous, longer than ampulla or about same length; unidiverticulate, diverticulum long tubular, stalk slender, ectal diverticulum, projected from anterio-lateral surface of duct, diverticulum comprehensively longer than duct plus ampulla ( Fig. 5C–D ). Genital marking glands absent.

Etymology. Specific epithet ‘ priyasankari’ is an eponym, a masculine noun in genitive case. The species is named in honour of Prof. Priyasankar Chaudhuri, former Head, Earthworm Research Laboratory, Department of Zoology, Tripura University (a Central University) of North-eastern India, for his tremendous contributions to the biological and ecological studies on the earthworms of the Indian state of Tripura.

Ingesta . Chiefly colloids of fine soil, sand, and sparse organic matter like barks and leaflets.

Habitat. Hevea brasiliensis plantation with sandy loam soil. Soil pH is around 4.72.

Ecology. It seems to be an endogeic species, as indicated by the large quantity of fine soil, and sparse organic matter in the intestine.At the type locality, K. priyasankari sp. nov., was found to coexist with the native earthworm species, K. tripuraensis sp. nov.

Distribution. Endemic to India: Tripura State: Dhalai District: Kamalpur ( Fig. 6 ).

Remarks. Based on the number of spermathecal pores, species of the genus Kanchuria can be clustered into four different groups, viz., i) “ tripuraensis species-group” which is characterized by two unpaired (single) spermathecal pore at the ventromdeian line; ii) “ antrophyes species-group” which can be distinguished by the presence of two pairs of spermathecal pores; iii) “ turaensis species-group” it has three pairs of spermathecal pores, and iv) “ octotheca species-group” members of this group has four pairs of spermathecal pores. Species belonging to each groups are the following: tripuraensis species-group— K. tripuraensis Narayanan, Paliwal & Julka , sp. nov.; antrophyes species-group— K. antrophyes ( Stephenson, 1924) and K. sumeriana Julka, 1988 ; turaensis species-group— K. turaensis Julka, 1988 , K. daribokgrensis Lone, Tiwari, Thakur, Pearlson, Pavlíc ̌ek & Yadav, 2020, K. karorensis Lone, Tiwari, Thakur, Pearlson, Pavlíc ̌ek & Yadav, 2020, K. mohiskulensis Lone, Tiwari, Thakur, Pearlson, Pavlíc ̌ek & Yadav, 2020, and K. priyasankari Narayanan, Paliwal & Julka , sp. nov.; octotheca species-group— K. octotheca Julka, 1988 and K. makhulensis Lone, Tiwari, Thakur, Pearlson, Pavlíc ̌ek & Yadav, 2020.

Kanchuria priyasankari sp. nov. belongs to the turaensis species group. Including the new species described herein, this group consists of five species, namely, K. turaensis , K. daribokgrensis , K. karorensis , K. mohiskulensis , and K. priyasankari sp. nov. Within this group, K. priyasankari sp. nov. is very close to K. turaensis than other species of the group. K. priyasankari sp. nov. can be differentiated from the K. turaensis by the body dimensions (length 44–73 mm vs 250–350 mm; width 2–2.5 mm vs 4.5–5 mm; segments 78–207 vs 279–490), characteristics of the spermathecae (ampulla small ovoid, duct thin, sinuous, diverticulum long tubular vs ampulla ovoid to sausageshaped, duct thick short, diverticulum club-shaped). Inspection of the holotype (ZSIC An2201/1) of K. turaensis deposited at the National Zoological Collections of Zoological Survey of India (ZSIC), Kolkata, India, by one of the authors (RP), revealed that the prostatic duct is long, slender, sinuous, thinner entally, gradually thickened ectally, and the ectal end is strongly thickened, longer, and sessile on parietes ( Fig. 7 ). Whereas in K. priyasankari sp. nov., the prostatic duct is short, slender, with a light twist, same width throughout, ectal end spheroidal, sessile on parietes. K. priyasankari sp. nov. can easily be differentiated from K. daribokgrensis by the presence of seminal grooves, which are absent in latter. It can be differentiated from K. karorensis by the type of spermathecal diverticulum (ectal diverticulum vs ental diverticulum) and extent of prostate (in segments 18–21, 22, 23 vs in segments 18–19). Through the shape of the spermathecal ampulla (small ovoid vs large elongated sac-like) and extent of the prostate (in segments 18–21, 22, 23 vs in segments 17–19) one can easily distinguish K. priyasankari sp. nov. from the K. mohiskulensis . A detailed comparison of all the known Kanchuria species is provided in Table 1.

Figures

FIGURE 4. Kanchuria priyasankari sp. nov., A–B. Ventral view of anterior portion showing the locations of spermathecal pores; C–D. Ventral view of the male genital region. Abbreviations: Cl—Clitellum; Fp—Female pore; Gm—Genital marking; Mg—Male genital region; Mp—Male pore; Sp—Spermathecal pores; Sg—Seminal groove.

FIGURE 5. Kanchuria priyasankari sp. nov., A–B. Prostate, dorsal view, left side; C. Spermatheca, dorsal view of, left side; D. Spermathecae, dorsal view of, left side. Abbreviations: Pd—Prostatic duct; Pr—Prostate; Sa—Spermathecal ampulla; Sd— Spermathecal duct; Sdi—Spermathecal diverticulum.

FIGURE 6. Distribution of the newly described Kanchuria species in Tripura State, India

FIGURE 7. Kanchuria turaensis Julka, 1988, prostates, dorsal view of the holotype (ZSIC An2201/1) deposited at the National Zoological Collections of Zoological Survey of India, Kolkata, India. Abbreviations: Pd—Prostatic duct; Pr—Prostate.