Erepta odontina (Morelet, 1851)

Hyman, Isabel T. & Ponder, Winston F., 2010, A morphological phylogenetic analysis and generic revision of Australian Helicarionidae (Gastropoda: Pulmonata: Stylommatophora), and an assessment of the relationships of the family 2462, Zootaxa 2462 (1), pp. 1-148 : 87

Erepta odontina (Morelet, 1851)

Figures 29C , 31J–L , 33A

Material examined. Mauritius: AM C205302 (one specimen dissected, radula examined), native forest, summit of Le Pouce, 1990, O.L. Griffiths, K. Emberton .

Description. External morphology: Shell 6 whorls, golden-brown, not glossy, spire and apex raised. Protoconch sculptured with very fine spiral ribs; teleoconch with very fine microscopic spiral grooves and radial lirae. Whorl profile rounded above and below evenly convex periphery. Internal walls of early whorls complete; umbilicus closed. Animal white with some pale red-brown and grey pigmentation. Mantle laps absent. Right mantle lobe small, left and median mantle lobes very small. Sole of foot and caudal apparatus as for family; caudal horn small; caudal foss horizontal slit in tail.

Mantle cavity: As for family. Mantle with no visible minor blood vessels, pigmentation absent.

Digestive system: Oesophageal crop absent.

Genital system ( Figures 29C , 33A ): As for family. Carrefour and talon both not embedded in albumen gland. Free oviduct of medium length; capsular gland present; internal longitudinal pilasters present at base. Bursa copulatrix inserted on vagina, moderately long, more than half spermoviduct length; duct of bursa copulatrix wide, not distinguishable from bursa copulatrix, internally with wavy longitudinal pilasters. Vagina internally with longitudinal pilasters. Penis moderately long; epiphallus enters penis through simple pore; penis internally smooth, longitudinal penis pilasters present; apical diverticulum on penis present, internally with pustules. Penial sheath present, enclosing only penis (not enclosing penial diverticulum); muscle connecting top of penial sheath to epiphallus present; penis retractor muscle attached to side of epiphallic caecum. Epiphallus longer than penis, internally with longitudinal pilasters. Epiphallic retractor caecum very long, positioned in middle of epiphallus. Flagellum present, very long, thin; flagellum and distal part of epiphallus without internal cryptae and externally smooth and slender. Spermatophore soft capsule with firm tail pipe open at one end; tail pipe long, smooth.

Radula ( Figure 31J–L ): Relatively long and narrow. Central tooth with small ectocones; mesocone lanceolate, longer than tooth base. Lateral and marginal tooth fields distinguishable. Lateral teeth with endocone much smaller than central tooth ectocones; ectocone equal in size to those on central tooth; mesocone slightly longer than tooth base. Marginal teeth with endocones absent; ectocones shorter and narrower than the mesocone, not subdivided into extra teeth. Radular formula (37.12.1.12.37) × 96 rows.

Remarks. No anatomical details are available for the type species of Erepta , E. stylodon (Pfeiffer, 1842) . Erepta contains three species and is endemic to Mauritius ( Schileyko 2002b). In the phylogenetic analyses, Erepta odontina occupied a relatively basal position in a paraphyletic or polyphyletic Helicarionidae ( Figures 1–3 ).

Figures

FIGURE 1. Majority-rule consensus tree (1,743 trees, length 117 steps) from the morphological analysis containing representatives of all groups. Families and subfamilies are shaded and are labelled in bold if the group is not monophyletic.

FIGURE 2. Majority-rule consensus tree (646 trees, length 106 steps) from the morphological analysis with Dyakiidae and Urocyclidae excluded. Families and subfamilies are shaded and are labelled in bold if the group is not monophyletic.

FIGURE 3. Majority-rule consensus tree (770 trees, length 117 steps) resulting from the morphological analysis with two additional mantle lobe characters. Families and subfamilies are shaded and are labelled in bold if the group is not monophyletic.

FIGURE 29. Reproductive systems. A. Caldwellia angularis, AM C205299. B. Caldwellia imperfecta, AM C205300. C. Erepta odontina, AM C205302. D. Ctenophila caldwelli, AM C205301. E. Kalidos balstoni, AM C205303. Scale bars 1 mm (E), 2 mm (B, D), 5 mm (A, C). Abbreviations: alb, albumen gland; bc, bursa copulatrix; c, caecum; ca, carrefour; ep, epiphallus; fl, flagellum; fov, free oviduct; her, hermaphrodite duct; ov, ovotestis; pr, prostate; prm, penis retractor muscle; pt, penial sheath; ut, uterus; v, vagina; vd, vas deferens.

FIGURE 31. Radulae. A–C. Caldwellia imperfecta, AM C205300. D–F. Caldwellia angularis, AM C205299. G–I. Ctenophila caldwelli, AM C205301. J–L. Erepta odontina, AM C205302. M–O. Kalidos balstoni, AM C205303. P–R. Madagascan species MA1, AM C205304. Scale bars 10 mm (A–C), 20 mm (D–L, P–R), 50 mm (M–O).

FIGURE 33. Penis interiors. A. Erepta odontina, AM C205302. B. Kalidos balstoni, AM C205303. C. Madagascan species MA1, AM C205304. D. Sheldonia poeppigii, NMSA L5563. E. Elisolimax flavescens, NMSA V9710. F. Parmarion martensi, BPBM 252738. G. Coneuplecta pampini, AM C438751. H. Hiona pilsbryi, BPBM 206801 & 20701. I. Trochomorpha rubens, FMNH 175247. J. Videna planorbis, FMNH 160957. K. Dendrotrochus eva eva, FMNH 175196. L. Orpiella concavum, BMNH no registration number. Scale bars 1 mm (A, C–D, F–H, J, M), 2 mm (B, E, I, K). Abbreviations: bc, bursa copulatrix; c, caecum; ep, epiphallus; fov, free oviduct; ovi, ovipositer; p, penis; pp, penial pilaster; prm, penis retractor muscle; ppu, penial pustules; pv, penial verge.