Aiyeriella longiprostata Narayanan & Julka, 2025

Narayanan, S. Prasanth, Thomas, A. P. & Julka, J. M., 2025, A new earthworm genus with two new species (Clitellata, Megascolecidae) from the Western Ghats mountain ranges of south-western peninsular India, Zootaxa 5575 (4), pp. 520-534 : 526-527

Aiyeriella longiprostata Narayanan & Julka , sp. nov.

( Figure 3 A–C ; 4 )

Type material. Holotype: Clitellate ( ZSIK Reg. No. ZSI/WGRC/I.R.INV.10330), below Muttidichantheri in Peppara Wildlife Sanctuary (8°37’18.8” N, 77°13’14.8” E), 12 km from Bonacaud and 68 km from Thiruvananthapuram (earlier Trivandrum), Thiruvananthapuram District, Kerala State, India, 737 m a.s.l., muddy blackish brown forest loamy soil and decaying wood in evergreen forest, with, 3 October 2014, collected by S. Prasanth Narayanan, S. Sathrumithra and Dinu Kuriakose. Paratypes. 3 clitellate, 1 aclitellate ( ZSIK Reg. No. ZSI/WGRC/I.R.INV.10331), same collection data as for holotype .

Other material. 1 clitellate, 4 aclitellates ( ACESSD /EW/850), Ponmudi hill top (8°46’6.2” N, 77°6’33.9” E), Thiruvananthapuram District, Kerala State, India, 1009 m a.s.l., evergreen ‘shola’ like forest with blackish brown forest loam soil, 2 October 2014, collected by S. Prasanth Narayanan, Dinu Kuriakose, S. Sathrumithra and S. Arun Sasi ; 1 clitellate, 6 aclitellate ( ACESSD /EW/851), Udiyankulangara (8°22’37.4” N, 77°7’32.7” E), Thiruvananthapuram District, Kerala State, India, 41 m a.s.l., home surroundings with various grass species, lateritic soil with humus, 1 October 2014, collected by S. Prasanth Narayanan, Dinu Kuriakose and S. Sathrumithra.

Diagnosis. Medium sized worm; length: 72–78 mm, width: 1.5–2 mm, 144–166 segments. Colour: pale reddish (unpigmented). First dorsal pore at 5/6, sometimes at 4/5. Clitellum annular, in segments 14–17 (= 4). Combined male and prostatic pores, paired at posterior ends of diagonally placed seminal grooves, lateral to a line; seminal grooves at centres of large ovoidal porophores on segment 18. Female pore single, median, presetal on segment 14. Spermathecal pores one pair, close to midventral line, in line with setae a, at anterior margin of segment 8. Genital markings absent. Gizzard muscular, barrel-shaped, in segment 5; intestine begins in segment 17. Last pair of hearts in segment 13. Holandric; testis and male funnels free, in segments 10 and 11; seminal vesicles paired, in segments 11 and 12. Prostates paired, tubuloracemose, strap-shaped, long, in segments 20–27, 30; penial setae absent. Spermathecae one pair, in segment 8, each with a shortly stalked club-shaped ectal diverticulum; duct about one-sixth the combined length of ampulla and duct.

Description. External. Body pale reddish, anterior end truncate. Dimensions: Holotype: length: 73 mm, width: 2 mm at segment 13, 165 segments; paratypes: length: 72–78 mm, width: 1.5–1.75 mm at segment 13, 144–166 segments. Prostomium proepilobic, retracted. First dorsal pore at intersegmental furrow 5/6, sometimes 4/5. Setae lumbricin; setal formula aa = 1–1.33 ab = 0.71–0.75 bc = 1–1.2 cd = 0.34–0.37 dd at segment 12, aa = 1.2–1.67 ab = 0.77–1.2 bc = 0.62–0.8 cd = 0.26–0.28 dd at segment 24. Clitellum annular, on segments 14–17 (= 4); intersegmental furrows distinct; dorsal pores occluded. Male porophores paired, large, somewhat ovoidal, diagonally placed on segment 18 with posterior ends converging towards mid-ventral line; each porophore with a diagonal groove at the centre; combined male and prostatic pores, paired, minute, at posterior ends of seminal grooves, lateral to a setal line, slightly anterior to intersegmental furrow 18/19 ( Fig. 3A ). Female pore minute, single, on midventral line, presetal, on segment 14. Spermathaecal pores, tiny, paired, close to midventral line, in a setal line, at anterior margin of segment 8, just behind intersegmental furrow 7/8 ( Fig. 3A ). Genital markings absent. Penial setae absent.

Internal. Unpigmented. Septa 5/6 delicate, 6/7/8/9 muscular, 9/10–12/13 slightly muscular. Gizzard well developed, muscular, barrel-shaped, in segment 5; oesophagus lightly enlarged, vascular in segments 13 and 14, calciferous glands absent; intestine begins in segment 17; intestinal caeca, supraintestinal glands and typhlosole absent. Dorsal and ventral blood vessels unpaired and complete; supraoesophageal vessel single, in segments 7–13; paired extra-oesophageal vessels median to hearts, in segments 5–13; lateroparietal vessels, paired, recognizable in 14–19 segments, turning upward along the anterior face of septum 13/14 to join extra-oesophageal vessels in segment 13. Last pair of hearts in segment 12. Holandric; testis and male funnels (iridescent) paired, free, in segments 10 and 11; seminal vesicles paired, lobulated, in segments 11 and 12, those of 12 large. Ovaries paired, each with several egg strings in segment 13; ovisacs paired, in 14. Prostates paired, tubuloracemose, strap-shaped, glands extend in segments 20–27, 30 ( Fig. 3B ), constricted by septa; prostatic duct muscular, straight, narrowed before entering the parietes at posterior margin of segment 18, just anterior to intersegmental furrow 18/19. Spermathecae paired, in segment 8, each with a shortly stalked club shaped ectal diverticulum (iridescent); duct equal or lightly longer than spermathecal diverticulum ( Fig. 3C ). Meronephric; paired tufts of astomate, micromeronephridia with ducts in sheaves; larger enteronephric tufts in segments 5 with ducts discharging into pharynx and in segment 6 with ducts extends anteriorly, discharging into buccal cavity in segment 2; smaller astomate, exonephric tufts in segments 7–16, discharging through composite ducts in their respective segments; astomate, exonephric clusters of 18–22 micromeronephridia on the body wall in segments 16–18; two transverse bands of 10–14 astomate exonephric micromeronephridia on body wall, just posterior to septa on segment 19 and posteriad segments, one band at ac setal lines and the other just lateral to d lines ( Fig. 4 ).

Etymology. The specific epithet ‘ longiprostata’ derived from two Latin words, ‘ longus ’ and ‘ prostata’, means “long prostate gland”, referring to the long prostate glands in the species.

Ingesta. Mainly silt, sparse wood particles, organic debris, and rootlets.

Habitat. Evergreen, evergreen shola (a kind of cloud-forest of Western Ghats, see Bunyan et al. 2012) like forest and home surroundings with various grass species. Muddy forest loam and lateritic soil with humus.

Ecology. Appears to be an endogeic species, as indicated by the few organic particles, the large quantity of silt in the intestine and the lack of pigmentation. At type locality, specimens were found in the mineral soil and in decaying wood. Small castings were present in the decaying wood. It was found associated with Dichogaster affinis ( Michaelsen, 1890) , D. bolaui ( Michaelsen, 1891) and Megascolex insignis Michaelsen, 1910 at Udiyankulangara (ACESSD/EW/851).

Distribution. India: Kerala: Thiruvananthapuram District: below Muttidichantheri in Peppara Wildlife Sanctuary, Ponmudi, Udiyankulangara. It seems to be widespread equally from the low-altitude regions to the high-altitude regions. Endemic to the Thiruvanathapuram district ( Fig. 5 ).

Remarks. For the differences of A. longiprostata Narayanan & Julka sp. nov. from the only other known species of the genus, see the remarks section of A. quadritheca Narayanan & Julka sp. nov. described elsewhere in this paper. A detailed comparison of the characters of these two species is provided in Table 2 .

Figures

FIGURE 3. Aiyeriella longiprostata Narayanan & Julka, sp. nov., A. Ventral view of anterior region; B. Prostate, dorsal view, right side; C. Spermathecae, side view, slightly stretched. Cl—Clitellum, Fp—Female pore, Pd—Prostatic duct, Pr—Prostate, Sa—Spermathecal ampulla, Sd—Spermathecal duct, Sdi—Spermathecal diverticulum, Se—Septum, Sg—Seminal groove, Sp—Spermathecal pore, Vd—Vasa deferens.

FIGURE 4. Aiyeriella longiprostata Narayanan & Julka, sp. nov., nephridial condition posterior to segment 19, right side, dorsal view (some of the anterior nephridia were lost during the preparation). Ne—Nephridia.

FIGURE 5. Distribution of the Aiyeriella species in Kerala.