Hiona (Hionarion) pilsbryi Baker, 1940

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 : 112-113

Hiona (Hionarion) pilsbryi Baker, 1940

Figures 33H , 38C , 39F

Material examined. Hawaii: BPBM 206801 & 20701 (one specimen dissected), Kipu, Kauai, valley directly back of stables, 14 Mar. 1910, M.C. Cooke .

Description. External morphology: Shell not examined. Animal pale brown. Right mantle lap moderately long, narrow, finger-shaped, left mantle lap absent, mantle laps uniform in colour. Mantle lobes small. Sole of foot tripartite; caudal apparatus formed from curled up sole ( Muratov’s 1999 helicarionid type); caudal horn overhangs foot slightly; caudal foss vertical slit in tail.

Mantle cavity ( Figure 38C ): As for family. Pigmentation and mantle gland absent.

Digestive system: Oesophageal crop absent.

Genital system ( Figures 33H , 39F ): As for family. Oviduct non-glandular, containing three embryos. Postuterine oviduct very long, internal longitudinal pilasters absent. Bursa copulatrix inserted on penis, very short, shorter than free oviduct; duct of bursa copulatrix wide, not distinguishable from bursa copulatrix, internally smooth. Penis moderately long; epiphallus enters penis through simple pore; penis internally smooth, one longitudinal penis pilaster present, penial diverticulum absent. Penial sheath present, enclosing coiled penis and epiphallus; penis retractor muscle attached to junction of penis and epiphallus. Epiphallus shorter than penis, simple internally. Epiphallic retractor caecum absent; Flagellum and lime-sac absent. Spermatophore not present in dissected specimens.

Radula: Not examined.

Remarks. The shell, anatomy and radula of this species were figured by Baker (1940). Ten subgenera of Hiona were accepted by Baker (1940); eight of these were used by Schileyko (2002a). Hionarion contains only two species, both from the Hawaiian Island of Kauai ( Schileyko 2002a).

In the phylogenetic analysis Hiona pilsbryi grouped with other Microcystinae from Vanuatu, Norfolk Island and Lord Howe Island ( Figures 1–3 ). In the molecular phylogenetic analysis of Wade et al. (2006), Hiona sp. was the only microcystid and grouped with Louisia and Euconulus (Euconulinae) ( Figure 44B ).

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 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.

FIGURE 38. Mantle cavities. A. Everettia sp., BPBM 20020188. B. Coneuplecta pampini, AM C438751. C. Hiona pilsbryi, BPBM 20680 & 20701 (mixed). D. Trochomorpha rubens, FMNH 175247. Scale bars 2 mm (B–D), 5 mm (A). Abbreviations: i, intestine; k, kidney; mc, mantle collar; pc, pericardium; pv, pulmonary vein; ur1, primary ureter; ur2, secondary ureter.

FIGURE 39. Reproductive systems. A. Everettia sp., BMNH 20020188. B. Lamarckiella lamarckiana sibuyanensis, FMNH 201967. C. Coneuplecta pampini, AM C438751. D. Coneuplecta calculosa, AM C377891. E. Coneuplecta dahli, MNHN no registration number. F. Hiona pilsbryi, BPBM 206801. G. Liardetia doliolum, BPBM 253684. Scale bars 1 mm (C–E, G), 2 mm (F), 5 mm (A–B). Abbreviations: alb, albumen gland; bc, bursa copulatrix; ca, carrefour; e, eggs / embryos; ep, epiphallus; fov, free oviduct; her, hermaphrodite duct; m, muscle attaching penial sheath to epiphallus; ov, ovotestis; p, penis; pd, penial diverticulum; pr, prostate; prm, penis retractor muscle; pt, penial sheath; pv, penial verge; st, stimulator; ut, uterus; v, vagina; vd, vas deferens.

FIGURE 44. Trees resulting from the phylogenetic analysis of two molecular datasets. Families and subfamilies are shaded. A. Mitochondrial gene cytochrome c oxidase subunit I [after Hyman et al. (2007)]. B. Nuclear gene 28S rRNA [after Wade et al. (2006)].