Mysticarion porrectus ( Iredale, 1941 )

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 : 36-38

Mysticarion porrectus ( Iredale, 1941)

Figures 5B , 6C , 7F , 8F , 9F , 12C , 13C , 15D–F , 16A

Helicarion porrectus ( Iredale, 1941) 1992: 234 .

Material examined. New South Wales, Australia: Probable holotype: AM C101136 (one shell measured, photographed), NW of Sydney , Blue Mountains, Mt. Irvine (33º29' S, 150º28' E), pre 1941, M. Ward .

Other material: AM C165048 (one specimen dissected), NW of Sydney , Blue Mountains National Park , N of Katoomba, Mount Wilson (33º31' S, 150º22' E), on tree ferns, 9 Feb. 1991, G.A. Clark , R. deKeyzer; AM C205296 (one specimen dissected, radula examined), Forest Rd. , at the entrance to the Mountaineer Trail, Barrington Tops National Park Wilderness Area (32º07.56’ S, 151º40.68’ E), mixed beech and Callicoma forest, in trees, on bark and the underside of leaves, 9 Feb. 2002, M. Shea, I. Hyman, C. Urquhart ; QMMO29298 (two specimens dissected, one radula examined), Robertson Nature Reserve , Robertson (34º36' S, 150º36' E), warm temperate rainforest, on leaves of trees, 4 Jan. 1990, J. Stanisic, J. Chaseling ; QMMO20281 (one specimen dissected), Point Lookout , New England National Park, rainforest, crawling on trees, 7 Jan. 1989, J. Stanisic, J. Chaseling ; QMMO37006 (one specimen dissected), Kookaburra Walking Trail, ca. 0.5 km NW of Kookaburra Forestry Camp, Carrai State Forest, NW Kempsey (31º01'25'' S, 152º20'05'' E), warm temperate rainforest, on trees feeding on lichen and moss, 10 Jan. 1992, J. Stanisic, J. Chaseling ; QMMO27296 (one specimen dissected), Gibraltar Range National Park , W of Grafton (29º31' S, 152º25' E), on leaves of trees in rainforest, 4 Mar. 1990, D. & N. Potter .

Queensland, Australia: QMMO24253 (one specimen dissected), summit Mt. Superbus, 1300 m , 8 Feb. 1990, G. Monteith, G. Thompson, H. Janetski .

Description. External morphology: Shell ( Figures 7F , 8F , 9F , 16A ) reduced, 3.3–3.6 whorls, orangebrown, spire flat, apex slightly raised, shape and sculpture as for genus. Animal ( Figure 5B ) cream. Mantle laps wide at base, moderately long, rounded, not fused, uniform in colour. Right and median mantle lobes of medium size, left mantle lobe small. Caudal horn small to medium; caudal foss vertical or diamond-shaped slit in tail.

Mantle cavity: As for genus. Pigmentation of few white spots sometimes present.

Digestive system: As for genus.

Genital system ( Figures 12C , 13C ): As for genus. Free oviduct moderately long; internal longitudinal pilasters absent. Penis moderately short; epiphallus enters penis through short verge (about a quarter of penis length or less); penis internally covered in irregular longitudinal ridges, two longitudinal penis pilasters present. Epiphallus shorter than penis, internally with two longitudinal pilasters.

Radula ( Figure 15D–F ): As for genus. Central tooth mesocone slightly longer than tooth base. Marginal teeth subdivided into three to five extra teeth towards outer edge. Radular formula (106.12.1.12.106) × 126 rows (QMMO 29298); (86.11.1.11.86) × 130 rows (AM C205296), (~100.12.1.12.~100) × 128 rows (AM C165048).

Range and habitat. The range of Mysticarion porrectus was previously thought to be quite narrow, including only the Blue Mountains region in New South Wales. However, in the current study, specimens from around Barrington Tops, Wauchope, Dorrigo and Casino (just south of the New South Wales-Queensland border) have been included in this species, dissections having shown their anatomy to be identical to the Blue Mountains species. Populations from the Wyong and Olney State Forests in mideastern New South Wales may also belong to M. porrectus (J. Stanisic, pers. comm.) but were not examined in the current study. There is also a single specimen in the Australian Museum from southwest of Narooma in southern New South Wales. Thus M. porrectus appears to have a wide but apparently discontinuous range.

Mysticarion porrectus usually occupies rainforest, but can also be found in vine thickets and open eucalypt forest. The species is arboreal and is most commonly found on tree trunks and the underside of leaves and fern fronds. It is also occasionally found in leaf litter and on mossy rocks.

Another species belonging to this genus, Mysticarion insuetus , was not examined in the current study but was described from around Scone. It is probably sympatric with Barrington Tops populations of M. porrectus . However, it is usually found in drier habitats (Stanisic et al., in preparation). Mysticarion insuetus can be distinguished from M. porrectus by its smaller size and slightly raised spire. No anatomical information is available for M. insuetus .

Remarks. Specimens from several widely dispersed and isolated regions were examined, with the expectation that these might have diverged into separate species. Instead, these specimens were found to be identical to M. porrectus in every detail, including the internal structure of the penis; for this reason all populations examined have been provisionally included in M. porrectus pending DNA studies.

Populations of Mysticarion porrectus from the Beaury State Forest in northern New South Wales are sympatric with M. hyalina . Mysticarion porrectus can be distinguished from M. hyalina by its more reduced shell and anatomically by the presence of two penial pilasters ( M. hyalina has only one) and a shorter penial verge.

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 6. Live Helicarionidae. A–B. Helicarion mastersi, AM C399075. Whole animal (A); close-up of caudal region (B) (arrow shows caudal mucous plug). C. Eggs of Mysticarion porrectus, AM C421841. D. Parmavitrina megastoma, AM C377461. E. Parmavitrina sp., AM C398947. F. Peloparion iridis, AM C161946. G. Peloparion iridis, Mt. Ravensbourne. H–I. Fastosarion superba. J. Stanisicarion freycineti, AM C391188. K. Stanisicarion virens. L. Eungarion mcdonaldi. M. Eggs of Eungarion mcdonaldi. N. Parmacochlea fischeri, AM C106767. Photographs by A. Miller (A–C, E, J), M. Shea (D), W. Rudman (F), F. Millen (N), all copyright Australian Museum; photographer unknown, copyright Queensland Museum (G–I, K–M).

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).

FIGURE 16. Microsculptures of the protoconch (A–E) and teleoconch (F–I). SEM. A. Mysticarion porrectus, AM C165048 (protoconch). B. Nitor circumcincta, AM C365822 (protoconch). C. Tarocystis responsivus, AM C425327 (protoconch). D. Coneuplecta calculosa, AM C377743 (protoconch). E. New genus C patescens, AM C120654 (protoconch). F. Nitor circumcincta, AM C365822 (teleoconch). G. Tarocystis responsivus, AM C425327 (teleoconch). H. Coneuplecta calculosa, AM C377743 (teleoconch). I. New genus C patescens, AM C120654 (teleoconch). Scale bars 100 mm (D, I), 200 mm (A–C, E–H).