Peloparion helenae (Godwin-Austen, 1883)

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 : 42-43

Peloparion helenae (Godwin-Austen, 1883)

Figures 5E–F , 7I , 8I , 9I , 12F , 13F , 15M–O

Helicarion helenae Godwin-Austen, 1883: 146 , pl. 41, figs 1–8; Tryon, 1885: 170, pl. 38, figs 50–51; Cox, 1909: 6. Peloparion submissus Iredale, 1941: 7 , fig. 8; Smith, 1992: 240.

Peloparion helenae: Iredale, 1941: 7 ; Smith, 1992: 240.

Material examined. New South Wales, Australia: Holotype of P. submissus: AM C 101142 (one shell measured, photographed), Scone (32º3' S, 150º52' E), pre 1941.

Other material: AM C205295 (one specimen dissected, radula examined), Barrington Tops National Park , Mountaineer Trail, ~ 2 km from the beginning of the trail (at Forest Rd.) (32º07.17’ S, 151º40.20’ E), mixed beech forest, in leaf litter, 9 Feb. 2002, M. Shea, I. Hyman, C. Urquhart ; AM C337633 (one specimen dissected), W of Gloucester , Chichester State Forest, Berrico Rd., 2.3km N of Kunungra Rd. (32º6.49' S, 151º45.9' E), 4 Feb. – 9 Apr. 1993, presented by M. Gray & G. Cassis .

Description. External morphology: Shell ( Figures 7I , 8I , 9I ) reduced, about 2.7 whorls, light orangebrown; protoconch sculptured with incised spiral grooves, otherwise shape and sculpture as for genus. Animal ( Figure 5E–F ) cream with red edge to foot and brown spots on side of foot; tiny specks of pale pigment present (similar pigment is iridescent in live specimens of P. iridis ). Right mantle lap large, rounded; left mantle lap slightly smaller, tapering to a point; colour and fusion as for genus. Mantle lobes of medium size; left and median mantle lobes fused. Caudal horn moderately large.

Mantle cavity and digestive system: As for genus.

Genital system ( Figures 12F , 13F ): As for genus. Bursa copulatrix short, less than half spermoviduct length; duct of bursa copulatrix narrow. Penis short, very wide; epiphallus enters penis through a medium verge, less than half penis length; penis internally smooth, one longitudinal and one circular penis pilaster present. Epiphallus approximately equal to penis length, simple internally. Epiphallic flagellum without externally visible cryptae, distal part of epiphallus with small internal cryptae forming external projections. Spermatophore soft capsule with firm tail pipe open at one end, tail pipe moderately long, narrow, sculptured at base of capsule with few short branching spines.

Radula ( Figure 15M–O ): As for genus. Radular formula (48.12.1.12.48) × 120 rows.

Range and habitat. Peloparion helenae appears to be restricted to the region around Scone, New South Wales. It is known from the Chichester State Forest, NW of Dungog, and Barrington Tops National Park. This appears to disagree with the type locality, which was given as Sydney ( Godwin-Austen 1883b). However, Godwin-Austen (1883b) mistakenly illustrated animals belonging two species in his original description [see Hyman (2007) for more details], one of which was from Sydney and is now known as Peloparion iridis (Hyman 2007) . The type locality of synonym P. submissus was Scone. Peloparion helenae is partially arboreal in habitat, having been found on tree leaves and under loose bark on trees as well as from leaf litter.

Remarks. The name Peloparion helenae has previously been used to refer to a larger semislug with a grey or brown body colour from Sydney. Hyman (2007) showed that Godwin-Austen (1883b) inadvertently illustrated two species in his original description of Helicarion helenae , a larger grey species (shell diameter 12–14 mm) and a smaller red-coloured species from around Scone (shell diameter 7 mm). The specimens that were dissected and on which he based his description were the smaller red animals, so the name Peloparion helenae was retained for this species and Peloparion iridis introduced for the larger grey animal (Hyman 2007).

Peloparion helenae was synonymised with Helicarion hyalinus ( Iredale 1937c) , but later separated ( Iredale 1941), a decision upheld by Smith (1998) and Smith et al. (2002).

The small range of P. helenae contrasts with the extremely wide but disjunct range of P. iridis , which includes specimens from around Sydney and from around the New South Wales-Queensland border (Hyman 2007). The two species are not sympatric.

Another specimen from the same region was also dissected (AM C168888). This specimen appeared to be identical to P. helenae externally, but differed in the presence of a shorter flagellum with internal cryptae. There may also have been some slight differences in the penis interior, but the penis was everted and this was difficult to ascertain. These differences are considerable and it is possible that a second cryptic species is present. However, since P. helenae is recognised based on the reproductive system described by Godwin-Austen (1883b), it is clear that the name is being used for the correct species.

Figures

FIGURE 5. External morphology of semislugs. A. Helicarion cuvieri, AM C424333 (Corinna, TAS). B. Mysticarion porrectus, QMMO29298 (Robertson, SE NSW). C. Mysticarion hyalina, AM C128630 (Cunningham’s Gap, SE QLD). D. Parmavitrina planilabris, AM C334357 (Wauchope, NSW). E–F. Peloparion helenae, AM C205295 (Barrington Tops, NSW). G. Stanisicarion virens, QMMO19234 (Brisbane, SE QLD). Scale bars 2 mm (B–C, E–G), 5 mm (A), 10 mm (D). Abbreviations: cah, caudal horn; cp, caudal pit; lla, left mantle lap; mlo, median mantle lobe; rla, right mantle lap; rlo, right mantle lobe; sh, shell.

FIGURE 7. Shells, dorsal view. A. Helicarion cuvieri, AM C443929. B. Helicarion cuvieri, BMNH 197780 (S of Vitrina verrauxii). C. Helicarion mastersi, AM C101139 (H). D. Helicarion mastersi, AM C101138 (PRH of H. mastersi callidus). E. Mysticarion insuetus, AM C113776 (S). F. Mysticarion porrectus, AM C101136 (PRH). G. Mysticarion hyalina, BMNH 1983075 (H). H. Parmavitrina planilabris, AM C103630. I. Peloparion helenae, AM C101142 (H). J. Brevisentis jacksoniensis, BMNH not registered (S). K. Brevisentis jacksoniensis, AM C101143 (H of B. exclusus). L. Fastosarion superba, BMNH not registered (POS). Scale bars 3 mm (G, I–K), 5 mm (A–F, H), 10 mm (L). Photographs by M. Allan (D, I), H. Barlow (A, C, H), D. Beechey (E–F, K), W. Ponder (B, G, J, L). Abbreviations: H, holotype; POS, possible syntype; PRH, probable holotype; S, syntype.

FIGURE 8. Shells, lateral view. A. Helicarion cuvieri, AM C443929. B. Helicarion cuvieri, BMNH 197780 (S of Vitrina verrauxii). C. Helicarion mastersi, AM C101139 (H). D. Helicarion mastersi, AM C101138 (PRH of H. mastersi callidus). E. Mysticarion insuetus, AM C113776 (S). F. Mysticarion porrectus, AM C101136 (PRH). G. Mysticarion hyalina, BMNH 1983075 (H). H. Parmavitrina planilabris, AM C103630. I. Peloparion helenae, AM C101142 (H). J. Brevisentis jacksoniensis, BMNH not registered (S). K. Brevisentis jacksoniensis, AM C101143 (H of B. exclusus). L. Fastosarion superba, BMNH not registered (POS). Scale bars 3 mm (E–G, I–K), 5 mm (A–D, H), 10 mm (L). Photographs by H. Barlow (A, C–D, G–H, L), D. Beechey (E, J), W. Ponder (B, F, I, K). Abbreviations: H, holotype; POS, possible syntype; PRH, probable holotype; S, syntype.

FIGURE 9. Shells, ventral view. A. Helicarion cuvieri, AM C443929. B. Helicarion cuvieri, BMNH 197780 (S of Vitrina verrauxii). C. Helicarion mastersi, AM C101139 (H). D. Helicarion mastersi, AM C101138 (PRH of H. mastersi callidus). E. Mysticarion insuetus, AM C113776 (S). F. Mysticarion porrectus, AM C101136 (PRH). G. Mysticarion hyalina, BMNH 1983075 (H). H. Parmavitrina planilabris, AM C103630. I. Peloparion helenae, AM C101142 (H). J. Brevisentis jacksoniensis, BMNH not registered (S). K. Brevisentis jacksoniensis, AM C101143 (H of B. exclusus). L. Fastosarion superba, BMNH not registered (POS). Scale bars 3 mm (D–G, I–K), 5 mm (A–C, H), 10 mm (L). Photographs by H. Barlow (A, C–D, H–I), D. Beechey (F, K), W. Ponder (B, E, G, J, L). Abbreviations: H, holotype; POS, possible syntype; PRH, probable holotype; S, syntype.

FIGURE 12. Reproductive systems. A. Helicarion cuvieri, AM C424333. B. Helicarion mastersi, AM C334204. C. Mysticarion porrectus, AM C205296. D. Mysticarion hyalina, AM C128630. E. Parmavitrina planilabris, AM C334357. F. Peloparion helenae, AM C205295. G. Brevisentis jacksoniensis, AM C348670. H. Brevisentis jacksoniensis, AM C205293. I. Fastosarion superba, AM C425248. Scale bars 2 mm (C–D, F–H), 5 mm (A–B, E, I). Abbreviations: alb, albumen gland; bc, bursa copulatrix; c, caecum; ep, epiphallus; fl, flagellum; fov, free oviduct; her, hermaphrodite duct; m, muscle attaching penial sheath to epiphallus (only shown in E); ov, ovotestis; p, penis; pr, prostate; prm, penis retractor muscle; pt, penial sheath; ut, uterus; v, vagina; vd, vas deferens.

FIGURE 13. Penis interiors. A. Helicarion cuvieri, AM C424333. B. Helicarion mastersi, AM C334204. C. Mysticarion porrectus, AM C205296. D. Mysticarion hyalina, AM C128630. E. Parmavitrina planilabris, AM C334357. F. Peloparion helenae, AM C205295. G. Brevisentis jacksoniensis, AM C205293. H. Fastosarion superba, AM C425248. I. Stanisicarion freycineti, AM C391188. J. Stanisicarion virens, QMMO19238. K. Eungarion mcdonaldi, AM C438760. L. Parmacochlea fischeri, AM C441743. Scale bars 1 mm (A–D, F–G I, K–L), 2 mm (E, H, J). Abbreviations: c, caecum; ep, epiphallus; fl, flagellum; p, penis; pp, penial pilaster; ppu, penial pustules; prm, penis retractor muscle; pt, penial sheath; pv, penial verge; vd, vas deferens.

FIGURE 15. Radulae. SEM. A–C Helicarion mastersi, AM C334204. D–F. Mysticarion porrectus, QMMO29298. G–I. Mysticarion hyalina, AM C128630. J–L. Parmavitrina planilabris, AM C334357. M–O. Peloparion helenae, AM C205295. P–R. Brevisentis jacksoniensis, AM C205293. Scale bars 20 mm (A–I, M–R); 50 mm (J–L).