Eutyphoeus morehensis Tiwari & Yadav, 2025

Eutyphoeus morehensis Tiwari & Yadav sp. nov.

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Figs 2 View Fig , 14 View Fig ; Tables 1–2 View Table 1 View Table 2

Diagnosis

Length 96–150 mm, diameter 3–4 mm, segments 190–210. Closed epilobic prostomium. First dorsal pore in ix/x. Male genital orifices in xvii avestibulate, apenile. In intersegment 7/8, there is a single pair of spermathecal pores centred at b. Pair of presetal genital marking present ventrally in segments xiii at a on xvi paired, postsetal at ab. Septa 6/7/8 thickened. Lateral intestinal caeca in xxvii. Holandric, seminal vesicles in xii extends up to xiv. Three/four pairs of supra-intestinal glands. Prostate tubular, duct long muscular with one or two loops. Bidiverticulate spermathecae. Penial setae ornamented with circles of spine, shaft straight, tip bluntly rounded. Genital marking glands present.

Etymology

The epithet ‘ morehensis ’ refers to the name of Moreh, a small town located within the Tengnoupal district, which is significant as part of the species’ habitat. By incorporating ‘ morehensis ’ into its scientific name, this earthworm species pays homage to the geographical region where it was first discovered, highlighting the importance of local ecosystems in biodiversity conservation efforts.

Material examined

Holotype

INDIA – Manipur • clitellate (2–3 segments from the caudal region taken for DNA extraction); Kwatha Range, Yangoupokpi-Lokchao Wildlife Sanctuary ; 24.3238° N, 94.2923° E; 9 Oct. 2017; Shweta Yadav leg.; registration number – ZSI CZRC T/6 ; MNP17-1065-43A5 . GoogleMaps

Paratypes

INDIA – Manipur • 2 clitellates; Tengnoupal, Yangoupokpi-Lokchao Wildlife Sanctuary ; 24.3831° N, 94.1492° E; 10 Oct, 2017; Shweta Yadav leg.; MNP17-1061 - 43A1 GoogleMaps .

Other material

INDIA – Manipur • 6 specs; same data as for holotype; MNP17-1064 - 43 A4, GoogleMaps MNP17-1066 - 43 A6, GoogleMaps MNP17-1069 - 43 A9, GoogleMaps MNP17-1070 - 43 A10, GoogleMaps MNP17-1073 - 43 A13, GoogleMaps MNP17-1074 - 43 A14 GoogleMaps • 6 specs; same data as for holotype; MNP17-1097 - 44 A23, GoogleMaps MNP17-1098 - 44 A24, GoogleMaps MNP17-1099 - 44 A25, GoogleMaps MNP17-1101 - 44 A27, GoogleMaps MNP17-1102 - 44 A28, GoogleMaps MNP17-1103 - 44 A29 GoogleMaps .

Description

Holotype

Length 150 mm, diameter 3.94 mm at preclitellar region. Total number of segments ca 205. Prostomium closed epilobic. Color chilean pink, uniformly pigmented. First dorsal pore starts from intersegmental furrow of 9/10. Setae start from segment ii, aa: ab: bc: cd: dd = 2.62: 1.05: 2.34: 1: 10.63 on xii, aa: ab: bc: cd: dd = 3.03: 1: 1.93: 1.29: 9.47 on xxiv and dd <half circumference of body. Clitellum annular, covering ½ xiii–⅓ xvii. Spermathecal pore on intersegmental region of 7/8 centered at b, slit-like aperture, surrounded by swollen lips. Female pores in separate patch, paired, presetal at a on xiv. Male genital region appears as hemispherical, bowl-shaped structure covering segments 17 and 18, with narrow furrow separating them, avestibulate, apenile, on surface of body, male genital orifices discharge in transverse fissures on circular porophores surrounded with grooved rounded circle bounded with translucent margin, at b. Genital markings present on xvi paired, postsetal at ab with dark inner circle followed by whitish large swollen ring.

Septa 6/7/8 thickened present. Gizzard in viii. Pair of discrete intramural calciferous glands in xii. Intestine begins in xiv. Lateral intestinal caeca in xxvii. Typhlosole simple, lamelliform originated from xxviii. Ventral intestinal caeca 16–18, present in segments xxx–lvi. Supra-intestinal glands 4 pairs in segments lxxiv–lxxix. Last pair of hearts in xiii. Holandric, testis sac in x and xi, annular, seminal vesicles in ix and xii, posterior one extends up to xiv. Single pair of prostates extends from segments xvii to xix or xx. Each prostate has a long, muscular duct that opens into the body wall at segment xvii. Glandular part with one or two loops. One pair of spermathecae with two lateral diverticula, lobulated with 4–6 seminal chambers, which open separately into duct; ampulla oblate spheroid; duct slender, long, covered with bunch of nephridia. Penial setae two per battery, length 1.1 mm, width 0.036 mm, ornamented with circles of spine, shaft straight, tip bluntly rounded. Paired genital marking glands present on xvi, sessile.

Variation

Differences were noted in the number and position of the genital markings, especially in paratype MNP17-1061-43A1. The genital markings present in this paratype are on xiii, xiv, xv and xviii, paired, postsetal at a with 3 pairs of supra-intestinal glands in lxix–lxxiii.

Remarks

The novel species Eutyphoeus morehensis Tiwari & Yadav sp. nov. is classified within the hastatus group as proposed by Gates (1958). This group is characterized by holandric testes, a lumbricine arrangement of setae, a complete dorsal blood vessel, and paired female pores. Gates originally included four species in the hastatus group: E. hastatus Gates, 1929 , E. manipurensis manipurensis , E. marmoreus Gates, 1933 and E. bullatus Gates, 1933 . However, Gates (1958) limited this grouping to Burmese species of Eutyphoeus , while Indian species were placed in a separate category.

Subsequently, additional Indian species were discovered and incorporated into the hastatus group, including E. mizoramensis Julka, Ramanujam & Lalthanzara, 2005 ; E. phawngpuiensis Tiwari, Lone, Thakur, James & Yadav, 2021 and E. tawi Tiwari, Lone, Thakur, James & Yadav, 2021 . Given this expanded classification, we propose that Indian species such as E. incommodus ( Beddard, 1901) , E. annandalei Michaelsen, 1907 , and E. quadripapilatus Michaelsen, 1907 should also be included in the E. hastatus group, as they share the characteristic holandric male organs and paired female pores.

The novel species is distinct from other species in the group by the position of its spermathecal pores, which are centered at b, a trait shared only with E. tawi and E. marmoreus . In contrast, the spermathecal pores of E. manipurensis manipurensis , E. mizoramensis , E. quadripapilatus , and E. phawngpuiensis are located at a or ab, while those of E. annandalei and E. incommodus are positioned along the setal line of bc, and E. hastatus has at c.

Additionally, E. tawi and E. marmoreus are characterized by vestibulate male genital orifices, whereas the novel species is distinguished by its avestibulate male genital orifices ( Table 1 View Table 1 ).

DNA barcode

The COI barcode data for the holotype, with process ID IEW1019-17, has been assigned the BIN number BOLD: ADL1325. For the species Eutyphoeus morehensis sp. nov, the mean intraspecific divergence is 1.17%, with a maximum intraspecific divergence of 2.23%. Its nearest neighbor species is Eutyphoeus lamdengensis sp. nov. with a nearest neighbor distance of 10.6% ( Table 2 View Table 2 ). All paratypes and syntypes of the novel species share the same BIN number, BOLD: ADL1325, without any BIN discordance.