Innesoconcha rosacea, (IREDALE, 1944)

Hyman, Isabel T., Caiza, Jennifer & Köhler, Frank, 2023, Dissecting an island radiation: systematic revision of endemic land snails on Lord Howe Island (Gastropoda: Stylommatophora: Microcystidae), Zoological Journal of the Linnean Society 197 (1), pp. 20-75 : 69-70

INNESOCONCHA ROSACEA ( IREDALE, 1944)

( FIGS 5K–O , 6J , 22G–I , 25 , 26 ; TABLE 1 )

Tribocystis rosacea Iredale, 1944: 323 , pl. 20, fig. 7.

Melloconcha rosacea Smith, 1992: 238 ; Stanisic et al., 2010: 346–347; Hyman & Köhler, 2020: 112.

Tribocystis alma Iredale, 1944: 324 .

Melloconcha alma Smith, 1992: 237 .

Type material: Holotype, AM C.38940 ( Fig. 5K ), near The Pines (31°32.08′S, 159°4.14′E), 1912, R.Bell.

Holotype of Tribocystis alma, AM C. 63477 ( Fig. 5L ), North Ridge , between North Bay & Hunter Bay (31°31.06′S, 159°2.97′E), 1905, R.Bell.

Material examined: See Table 1 .

Description

External morphology: Shell ( Fig. 5K–O ) small ( SW 3.7–4.1 mm, SH 1.7–2.2 mm), 4.8–5.2 whorls, highly glossy, slippery, orange-brown to reddish brown, discoidal with a flat or slightly raised spire. Protoconch and teleoconch sculptured with fine microspiral grooves. Whorl profile rounded above and below a rounded periphery, sutures flat. Animal ( Fig. 6J ) grey, with darker grey eyestalks and tail tip. Right shell lappet long, narrow, finger-shaped, left shell lappet absent.

Pallial caƲity: Pigmentation absent; mantle gland present.

ReproductiƲe system ( Fig. 25 ): Oviduct with six eggs, one to three embryos. Penis short, not coiled; epiphallus enters penis through a simple pore or small verge (present in one specimen); penis internally flat, one to two longitudinal penis pilasters present; apical diverticulum on penis present. Penial tunica enclosing penis (not coiled) and epiphallus. Epiphallus shorter than penis, internally without sculpture.

Radula ( Fig. 22G–I ): Marginal teeth with ectocones slightly shorter and narrower than mesocone, multicuspidate. Radular formula (18.4.1.4.18) × 69.

Figures

Figure 5. Shells of Innesoconcha.A,B,Innesoconcha catletti.A,AM C.101187 (syntype).B, AM C.101188 (syntype of I.catletti major). C, Innesoconcha aberrans, AM C.63475 (holotype). D, Innesoconcha delecta, AM C.63478 (holotype). E, Innesoconcha doppelganger sp. nov., AM C.592779 (holotype). F, Innesoconcha flaƲescens, AM C.40600 (syntype). G, Innesoconcha grata, AM C.63479 (lectotype). H, Innesoconcha miranda, AM C.39175 (holotype). I, Innesoconcha prensa, AM C.63476 (holotype). J, Innesoconcha princeps, AM C.38958 (syntype). K, L, Innesoconcha rosacea. K, AM C.38940 (holotype). L, AM C.63477 (holotype of Melloconcha alma). M, Innesoconcha segna, AM C.114789 (possible holotype).

Figure 6. Live individuals of Innesoconcha. A, Innesoconcha catletti, AM C.532582, Research Station. B, Innesoconcha aberrans, AM C.593857, Mount Lidgbird mid-south-western slopes. C, Innesoconcha delecta, AM C.574679, Mount Gower summit. D, Innesoconcha flaƲescens, AM C.532623, Boat Harbour. E, I. flaƲescens, AM C.574741, Mount Lidgbird lower northern slopes. F, Innesoconcha grata juvenile, AM C.593.893, Mount Lidgbird mid-south-western slopes. G, Innesoconcha prensa, AM C.583114, Mount Gower summit. H, Innesoconcha princeps, AM C.574711, Mount Gower summit. I, I. princeps juvenile, AM C.574683, Mount Gower summit. J, Innesoconcha rosacea, AM C.583117, Dinner Run. Images by A. Moussalli (A, D), C. Stehn (B, C, E, F, H, I) and F. Köhler (G, J).

Figure 22. Radulae. Column one shows central tooth and adjacent laterals, column two shows the transition between lateral and marginal teeth, and column three shows the outer marginal teeth. A–C, Innesoconcha prensa, AM C.91378, Mount Gower. D–F, Innesoconcha princeps, AM C.91377, Mount Gower. G–I, Innesoconcha rosacea, AM C.391700, Old Settlement Beach. Scale bars: 20 µm (A–F); 10 µm (G–I).

Figure 25. Reproductive system of Innesoconcha rosacea. A, AM C.589618, Mount Eliza (clade X), reproductive system. B, C, AM C.583120, Mount Lidgbird (clade X). B, penis with tunica removed. C, penis interior. D, E, AM C.583117, Dinner Run Creek (clade Y). D, penis with tunica removed. E, penis interior. Scale bars: 1 mm.

Figure 26. Map showing the known range of Innesoconcha rosacea, based on collections data of the Australian Museum. A, historical collection data, showing how recorded distribution has changed over time. B, sequenced specimens, showing the distribution of clade X and clade Y from the phylogenetic tree.