Moniligaster ivaniosi Manazhy, 2011

Narayanan, S. Prasanth, Sathrumithra, S., Anuja, R., Christopher, G., Thomas, A. P. & Julka, J. M., 2021, Three new species and four new species records of earthworms of the genus Moniligaster Perrier, 1872 (Clitellata: Moniligastridae) from Kerala region of the Western Ghats Biodiversity Hotspot, India, Zootaxa 4949 (2), pp. 381-397 : 393-394

Moniligaster ivaniosi Manazhy, 2011

( Figure 5 )

Moniligaster ivaniosi Manazhy, 2011 : Manazhy et al. 2011: 11–12, Figs 3–5 .

Material examined. Holotype: Undissected and softened amputee (ZSI/ WGRC / IR /INV/2107). Moniligaster ivaniosi sp. nov., Family Moniligastridae, Loc. Port Blair , Andaman & Nicobar, Collr. Jaya M., Dt. 3.x.2009, Reg. No. 2107, Det. by Jaya M. (as given in the holotype label).

Description. External: Length 52 mm, diameter 2.1 mm, segments 125+, softened between segments 23 and 50. First two segments obliquely and partly ruptured towards left side. Cuticle loose, easily detachable. Clitellum indistinguishable. Spermathecal pores paired, small transverse slits, at intersegmental furrow 7/8, close to c setal lines ( Fig. 5A ); small, oval-shaped paired thickenings with definite borders in front of spermathecal pores. Male pores minute, paired, at centres of oval-shaped, slightly protuberant penes, well demarcated secondary male apertures at intersegmental furrow 10/11, between lines of setae b and c, each with a tiny genital marking anterior to it. Female pores minute, paired, close to b setal lines, at intersegmental furrow 11/12. Nephridiopores not recognizable.

Internal: Gizzards 3 in segments 12–14. Prostates paired, glandular, erect, somewhat club-shaped, slightly curved entally, about 1.5 mm long ( Fig. 5B ); vas deferens coiled into a mass of hairpin loops, mass about half the size of testis sac, entering the ental end of the prostate directly. Spermathecal atria paired, erect, saccular, in segment 7 ( Fig. 5B ); spermathecal duct, slightly coiled in middle, piercing through septum 7/8 to discharge at the ectal end of the atrium. Genital marking glands not recognizable.

Remarks. The taxonomic description of Moniligaster ivaniosi Manazhy, 2011 was based on three specimens ( Manazhy et al. 2011). The holotype was deposited with the Zoological Survey of India, Western Ghats Regional Centre, Kozhikode, Kerala (cat. No. ZSI/WGRC/IR-INV/2107), and two paratypes were retained in the Zoological Museum of Mar Ivanios College, Thiruvananthapuram, Kerala (cat. no. MICZ/AE/ANI/3-09), where the study by Manazhy et al. (2011) was conducted. Our examination of the holotype showed that it was not dissected, and anatomical characteristics of the species were presumably based on the paratypes, which were unavailable for the present study. We approached the authorities of Mar Ivanios College about the availability of paratypes of M. ivaniosi in the Zoological Museum of the college. However, they were to unable to locate the paratypes.

Dissection was performed on the holotype, and it revealed some errors in the description of the species relating to the following important taxonomic characteristics. 1) The male pores are at intersegmental furrow 10/11, not at 9/10. 2) Dichotomously branched glands in compact masses on y-shaped spermathecal atria, a distinguishing feature of the genus Moniligaster , are absent. 3) Copulatory sacs are stated to be paired in each of segments 6 and 7, which mean that there are two pairs of spermathecae. However, Moniligaster is a genus that by definition has only one pair of spermathecae [copulatory sac is an archaic term used in older publications (e.g., Benham 1893) for the atrial sac or the lobe at the ectal end of the spermathecal duct]; enlarged paired lateral hearts may have been mistaken for copulatory sacs as shown in the original figure of the species. 4) Prostate glands are erect and somewhat club-shaped rather than oblately hemispherical. In addition, the label of the holotype shows 'Jaya M.' as collector, not 'Oommen V. Oommen and K. Ramachandran', as in the published description of the species.

Lack of dichotomously branched glands on the spermathecal atria in the holotype of M. ivaniosi shows that this species does not belong to Moniligaster , but rather to the genus Drawida ( Michaelsen 1900; Stephenson 1923; Gates 1972). The internal features shown in Manazhy et al. (2011, Fig. 4 ) do not support the presence of these glands, either. The holotype has a paired, glandular, erect, club-like prostate, curved entally to a U-shape, prostatic capsule club-shaped; vas deferens coiled into a mass of hairpin loops, mass about half the size of testis sac, vas enters prostate directly at ental end; spermathecal atria paired, erect, saccular, spermathecal duct, enters at the ectal end of the atrium, owing to these key characters the holotype of M. ivaniosi is determined as Drawida nepalensis Michaelsen, 1907 ( Stephenson 1923; Gates 1972; Julka, 1982) a widespread peregrine moniligastrid in the Andaman Islands ( Julka 1982).

Manazhy et al. (2011) have incorrectly compared M. ivaniosi with Moniligaster ophidioides Bourne, 1894 and Moniligaster sapphirinaoides Bourne, 1886 , which since Michaelsen (1900) belong to Drawida . The key to the species of Moniligaster in Manazhy et al. (2011) is flawed. Of the 15 species included in the key, 13 do not belong to Moniligaster but to Drawida ( Michaelsen 1900, 1909; Stephenson 1923). At the same time, the valid species viz., Moniligaster aiyeri Gates, 1940 , Moniligaster cernosvitovi Gates, 1962 , Moniligaster gravelyi Stephenson, 1915 , Moniligaster horsti Gates, 1940 , Moniligaster michaelseni Gates, 1940 , Moniligaster stephensoni Gates, 1940 , and Moniligaster troyi Jamieson, 1977 are excluded from the key. These notable omissions seem to have vitiated the key and the erroneous identity of M. ivaniosi . It appears that Manazhy et al. (2011) have relied on outdated works of Bourne (1886) and Benham (1893) for species identification while ignoring more recent and well-known taxonomic treatises on Moniligaster by Stephenson (1923), Gates (1940, 1972) and Jamieson (1977).

Figures

FIGURE 3. Moniligaster keralensis Narayanan & Julka sp. nov. A. Ventral view. B. Prostate of right hand side, dorsal view. C. Prostatic capsule of right hand side, dorsal view. D. Spermatheca of left hand side. Abbreviations. M.H.L.—Mass of hairpin loops; Oe.—Oesophagus; Pr.C.—Prostatic capsule; Pr.—Prostate; Pr.D.—Prostatic duct; Sep.—Septum; Sp.A.—Spermathecal ampulla; Sp.Atr.G.—Spermathecal atrial gland; Sp.D.—Spermathecal duct; S.M.A.—Secondary male aperture; Sp.P.—Spermathecal pore; T.S.—Testis sac; Vd—Vas deferens.

FIGURE 4. Map of sampling localities of species of Moniligaster recorded in this study.

FIGURE 5. Moniligaster ivaniosi Manazhy, 2011, holotype (cat. no. ZSI/WGRC/IR/INV/2107). A. Ventral view. B. Dissected, showing important characters.Abbreviations. D.B.V.—Dorsal blood vessel; Giz.—Gizzard; L.H.—Lateral hearts; Pr.G.—Prostate gland; Sp.Atr.—Spermathecal atrium; T.S.—Testis sac; Vd—Vas deferens.