Siphonaria australis Quoy & Gaimard, 1833

Jenkins, Bruce & Köhler, Frank, 2024, Hidden in plain sight: Systematic review of Indo-West Pacific Siphonariidae uncovers extensive cryptic diversity based on comparative morphology and mitochondrial phylogenetics (Mollusca, Gastropoda), Megataxa 13 (1), pp. 1-217 : 48-50

Siphonaria australis Quoy & Gaimard, 1833

( Figs 15I–J , 17H–J, R–T )

Siphonaria australis Quoy & Gaimard 1833: 337 , pl. 25, figs 32–34 (type locality: ‘détroit de Cook, à la Nouvelle-Zélande’ [Cook Strait, New Zealand]).— Anton 1838: 26; Lamarck 1839: 207; Catlow & Reeve 1845: 100; H. Adams & A. Adams 1855 (in 1853–1858): 271, 1863: 271; Paetel 1873: 117; Hutton 1873: 55; 1878a: 42; 1880: 36; 1882: 24; 1883: 142, pl. 17, figs E–G; Filhol 1880: 552; Paetel 1883: 178; 1889: 428; Suter 1904: 68; Iredale 1908: 408; Moss 1908: 41, pl. 9, fig. 25; Suter 1913: 598. 1915: unpaginated text, pl. 24, fig. 6; Iredale 1915: 478; Oliver 1923: 498; Finlay 1927: 442; Powell 1937: 86; 1939: 217; 1946: 91; Knox 1954: 872; 1955: 86; Powell 1957a: 114; Dell 1960: 148; Morton & Miller 1968: 302, fig. 109, pl. 9, fig. 7, 7a; Galindo 1977: 416; Powell 1979: 292, pl. 54, fig. 11; Jenkins 1983: 1, 21, pl. 3a–I, 22, 4a–f; Trew 1983: 4; Paul 1984: 28; Russell & Phillips 2009: 579; Raven & Bracegirdle 2010: 46; White & Dayrat 2012: 61.

Siphonaria sipho — Hutton 1883: 143; Filhol 1880: 552 (not S. sipho Sowerby I, 1823 ).

Siphonaria zelandica — Lamarck 1836: 58; Hutton 1878a: 41; Filhol 1880: 552; Suter 1904: 68; 1913: 600; 1915: unpaginated text, pl. 24, fig. 8O; Odhner 1924: 55; Finlay 1927: 442; Powell 1933: 186; 1937: 86; 1939: 217; 1946: 91; Borland 1950: 386; Knox 1955: 68; Powell 1955: 120; 1957a: 114; Dell 1960: 147; 1963: 227; Morton & Miller 1968: 83, pl. 19, figs 8,a; Galindo 1977: 416; Powell 1979: 292, pl. 54 fig. 10; Trew 1983: 7; Wells & Wong 1978: 417 (not S. zelandica Quoy & Gaimard, 1833 ).

Siphonaria funiculata — Hutton 1873: 55 (not S. funiculata Reeve, 1856 ).

Siphonaria zealandica Hutton 1873: 55 ; 1880: 36; 1883: pl. 17, fig. H–M.— Oliver 1915: 547; Oliver 1923: 58 (in part); Bucknill 1924: 82, pl. 3, figs 16–16a (invalid; incorrect subsequent spelling of zelandica , not S. zelandica Quoy & Gaimard, 1833 ).

Siphonaria diemenensis — Hutton,1873: 55; Suter 1907: 141; 1909: 33 (not S. diemenensis Quoy & Gaimard, 1833 ).

Siphonaria inculta Gould 1846: 11 (type locality: NZ).— Gould 1848: 153; 1852: 153, fig. 465, a, b; H. Adams & A. Adams 1855 (in 1853–1858): 271; Gould 1856: 12, fig. 465, a, b; H. Adams & A. Adams 1863: 271; Hanley 1858b: 152; Hutton 1878a: 7; 1880: 36; 1883: 143; Paetel 1889: 428; Johnson 1964: 90; Jenkins 1983: 21, pl. 3b; Trew 1983: 5; White & Dayrat 2012: 64.

Siphonaria cancer Reeve 1856 : pl. 2, species 7 (type locality: NZ).— Hanley 1858b: 151; Paetel 1873: 117; Hutton 1873: 55; 1878a: 41; Filhol 1880: 552; Paetel 1883: 178; 1889: 428; Jenkins 1983: 2, 21, pl. 3c, d; Trew 1983: 5; White & Dayrat 2012: 61.

Siphonaria cookiana Suter 1909b: 258 (type locality: Lyall Bay, Cook Strait, [ NZ]).— Knox 1955: 86; Boreham 1959: 71 (both in part); Jenkins 1983: 1, 21, figs 3e–g.

Siphonaria (Siphonaria) australis — Hubendick 1946: 49.

Siphonaria canessi Galindo 1977: 416 (invalid; subsequent incorrect spelling of S. cancer ).

Siphonaria canuicer Galindo 1977: 416 (invalid; subsequent incorrect spelling of S. cancer ).

Material examined. Type material. Lectotype of Siphonaria australis Quoy & Gaimard, 1833 from ‘détroit de Cook, à la Nouvelle-Zélande’ [Cook Strait, New Zealand] MNHN IM 2000-5036 ( Fig. 17G ); paralectotype ( MNHN-IM-2000-5037 ), same data as lectotype.

Holotype of Siphonaria inculta Gould, 1846 USNM 5857 , possible paratype MCZ 169190 ( Fig. 17K ), same data as holotype (figured in Gould, 1852: 358, fig. 465, 465a, 465b and in Jenkins, 1983: 21, pl. 3b).

Lectotype of Siphonaria cancer Reeve, 1856 , NHMUK 198112 (figured in Jenkins, 1983: 21, pl. 3c), four paralectotypes NHMUK 198112 , same data as lectotype (figured in Jenkins, 1983: 21, pl. 3d).

Other, non-type material. NZ; North Island: Big Bay, Manakau Harbour , Auckland, 37°02.58’S 174°38.72’E ( AM C.265856 p [SK511 protoconch I6], Fig. 17S ) . South Island: N end Seaview Marina, Lower Hutt , 41°14.85’S, 174°54’E ( NMNZ M.331451, 2 p) . Stewart Is: Watercrest Bay , 46°54.223’S, 168°07.195’E STI01- 1 ( AM C.585953 4 p, C.585247 p [M480, SK289] Fig. 17H ); E of Ringaringa Bch, 46°54.544’S, 168°08.646’E STI02-1 ( AM C.585952 6p, C.585249 p [M481, SK088], Fig. 17I ) .

Taxonomic remarks. The lectotypes of S. australis and S. cancer have been designated by Jenkins (1983). Our delineation of S. australis is based on comparative analyses of the morpho-anatomy and mitochondrial genetics of freshly collected topotypes of S. australis ( Figs 17I–J ), S. inculta , S. cancer and S. cookiana (Tables S1–2). Siphonaria spinosa Reeve, 1856 is a junior synonym of S. aspersa Krauss, 1848 as based on examination of the types ( Jenkins, 1983: 29). Reeve (1856: pl. 7, fig. 32a, b) incorrectly stated this taxon to originate in NZ. Siphonaria inculta Gould, 1846 b was first figured in Gould (1852: 358, fig. 465a, b) and is considered a junior synonym of S. australis . Reference to ‘ S. cancer Reeve ’ in Swinhoe (1865: 165) from Formosa [ Taiwan] is based on a misidentification. Reference to S. zelandica , as a synonym of S. sipho , in Schrenck (1867: 306) is erroneous and a probable misidentification of S. australis . Hutton (1878a: 41) considered S. cancer to be a probable variety of ‘ S. zelandica ’, but is S. australis . He also (p. 42) misidentified specimens from ‘New Zealand’ (probably of S. australis ) as ‘ S. diemenensis’. Hubendick’s (1946: 49) interpretation of S. australis is partly confused: He incorrectly included S. zelandica and S. lentula (as lentulus ) in the synonymy of S. australis , which is rejected herein. The nominal species S. scutellum (= S. obliquata ) and P. innocuus (= S. exulum ) are here removed from the synonym of S. australis , but the synonymy of S. inculta and S. cancer is maintained.

Morrison (1972: 56–58) treated S. cancer as a synonym of S. laciniosa based on conchological similarity and ‘common reproductive development’. This is rejected herein based on examinations of types and comparative morpho-anatomy. Raven & Bracegirdle (2010: 46) incorrectly treated S. zelandica as a synonym of S. australis . The re-description of this species by Jenkins (1983) forms the foundation for the delimitation of this species in the present study.

External morphology ( Fig. 17R ). Foot sole smooth, pale cream/yellowish, paler to foot edge; foot wall pale grey-cream with irregular dark/black markings along foot wall & concentrated over cephalic lobes; genital pore conspicuous, located on foot wall posterior to right cephalic fold; fringing mantle thick, cream, translucent to transparent, extends to shell edge, outer edge with thick lobes, strong dark bands aligning with shell lip ribinterstices; pneumostomal lobe large and within mantle between the right ADMs, closes the pneumostomal and anal openings at the mantle edge; two small black epithelial eye spots centralised on two thick centrally touching cephalic folds that darken to their outer edge.

Shell ( Figs 17G–I ; Table S9). medium sized, ovate (max sl mean = 17.99 mm, SD = 1.93 mm, n = 99), asymmetrical, thick, height low to medium, edge often very uneven, exterior grey/light brown, uneven; rib count (mean = 28.5, SD = 4.4, n = 99), raised irregularly spaced radial ribs, broaden to edge, ridges rounded to flat; apex weakly offset to posterior and left, protoconch direction homostrophic (n = 1, Fig. 17S ), body whorl dextral; apical sides convex increasingly to shell margin, growth striae indistinct discontinuous, radial ribs project unevenly weakly beyond shell edge, particularly in larger specimens, dual primary ribs form siphonal ridge, project furthest; rib interstices brown, furrowed often fairly deep. Interior glossy, uneven, light brown to tan, margin chocolate brown with white rays aligning under ribs; ADM scar paler, spatula pale blue/yellowish tan, siphonal groove usually mottled dark brown or grey, CMS straight to convex.

Reproductive system ( Fig. 15I; n = 3). Positioned within coelom under the respiratory cavity, hermaphroditic glands positioned to posterior against right foot wall & over foot sole, epiphallic parts positioned between BM and to side of RAM; GA bulbous, GP distinct, protrudes; AO indistinct, merges with bulbous GA; ED relatively short, narrow, twisted close to GA; EG large, unfolded, rounded; single long, uncoiled flagellum F1, extends from end of wider EG; AO, GA and ED all muscular white tissue; BD and CD junctions into GA side-by-side & close to opposing ED connection; BD longer, slightly narrower than CD without distal loop, both ducts, fused, smooth unfeatured, pass together through outer side of RAM connecting into folds of MG ( BD above CD); BC translucent test, midsized, elongate bulbous, embedded in AG; large heavily coiled HD, connects soft white folded tissues of AG to smaller elongated brownish finely granulated HG; MG at distal end of AG; dark SV centrally embedded within AG near top of BC, AG larger than HG, sides match curvature of inner foot wall at right posterior quarter of coelom.

Spermatophore ( Fig. 15J ). Body cylindrical, thread-like (length = 6.1 ± 2.4 mm, n = 2), test thin, translucent; head tip tapered bluntly rounded, section containing a white gelatinous core, tapers to a thin flagellum & tip; both sections smooth, featureless; head longer, thicker than flagellum (head length = 5.27 ± 2.19 mm, ~ 86% of SPM length; head width = 89 μm ± 7 μm, flagellum width = 24 ± 10 μm, n = 2). Typically, SPM tightly coiled in BC, embedded in white gelatinous mass.

Radula (adapted from Jenkins 1983: 17). Mean dentition formula 35:1:35 (SD = 7.01) with 127 (SD = 7.33, n = 5) transverse rows; 35 half row laterals, of which 20 mid (SD = 4.98) and 15 outer (SD = 3.58) laterals (n = 5); central tooth single pointed mesocone, inner laterals absent, mid laterals with bluntly pointed mesocone and broad pointed ectocone ( Jenkins, 1983, pl. 6d, e), ectocone strong, protrudes at acute angle halfway along the tooth’s length; outer lateral with a ‘chisel’ shaped pointed mesocone flanked by small, irregularly pointed, single ecto and endocones ( Jenkins 1983: pl. 6f), angle of separation of each cone from the mesocone varies. Dentition formula: 36:1:36 ( Hutton, 1883: 142), 30:1:30 ( Hubendick 1946: 49).

Comparative remarks. Siphonaria australis ( lateralis group, unit 86) is the sister species of S. propria ( Figs 1 , 4 ). Both species form a subclade in Clade D together with S. jeanae and S. diemenensis . From its closest relative, S. propria , this species differs by COI distances of ≥ 10.4%. From other species, S. australis differs by distances of ≥ 19% (Table S8). Within its range S. australis is found in sympatry with two congeners: For comparison with S. obliquata refer to comparative remarks under that species. Siphonaria propria has a slightly smaller shell with a more prominent siphonal ridge, posteriorly left offset apex, regular ribbing and a consistently internal tan to off white siphonal groove, as well as a smaller to inconspicuous AO and longer F1.

Some authors were uncertain of the identity of S. australis . Specimens figured in Hubendick (1946: pl. 3, figs 28–31) have been correctly identified as S. australis ; however, the corresponding description ( Hubendick 1946: 49) incorrectly includes specimens from Port Jackson [Sydney], Australia (likely S. denticulata ). Hubendick (1946) incorrectly included Port Jackson and Norfolk Island in the distribution of this species. The radula description matches that of Hutton (1883: 124, pl. 17, figs E–G).

Distribution and habitat. Recorded from New Zealand, North and South Islands, Chatham, Stewart, and Snares Islands, between latitudes of 34° and 48° S) ( Fig. 16 ). In this study found to be common in sheltered positions (e.g., crevices, vertical faces) on exposed to semi-exposed rocky intertidal shores across upper and mid littoral levels (see also Jenkins 1983: 14).

Figures

FIGURE 1. Maximum Likelihood phylogram based on analyses of a concatenated sequence data set of 16S and COI. Branches are collapsed at the species level. Branch labels give unit numbers and accepted species names. Numbers on branches indicate branch support employing 10,000 ultrafast bootstraps.Available genus-group names are shown next to their type species. Scale bar indicating modelled sequence divergence.

FIGURE 4. Maximum Likelihood phylogram (partial, species not collapsed). Clades C–F (normalis, lateralis and pectinata groups) of the tree shown in Fig. 1. Branch labels give specimen identifiers for new sequences or Genbank accession numbers for imported sequences from other studies and geographic regions (see Tables S1–S2 for details). Identical haplotypes are merged into single tips. Numbers on branches indicate branch support by employing 10,000 ultrafast bootstraps. Clade names give unit numbers and accepted species names. Scale bar indicating modelled sequence divergence.

FIGURE 15. Reproductive anatomy of S. javanica, S. obliquata, and S. australis. A. S. javanica. Timor-Leste, Dili, AM C.584795 [M434]. B–E. S. japonica. B–C. Hong Kong, ZRC.MOL.24905 [M476, SK283]. D–E. Honshu, Boso Peninsula, Neotype AM C.584938 [M489, SK308]. F–H. S. obliquata. F–G. NZ, Dunedin, Neotype NMNZ M.331450 [M515, SK421]. H. South Island, West Coast, TS, NMNZ M.331115 [M516, SK422]. I–J. S. australis I–J. NZ, Stewart Is, AM C.585247 [M480, SK284]. Unlabelled scale bars 1 mm.

FIGURE 16. Known occurrence records of S. obliquata, S. radiata, S. diemenensis, S. australis, S. atra and S. denticulata

FIGURE 17. Shells of S. radiata, S. diemenensis, S. australis and S. capensis. A–B, U–V. S. radiata. A. Malaysia, Port Dickson, neotype AM C.585861 [M408]. B. Malacca, ZRC.MOL.24891 [SK348]. U. Port Dickson, in situ. V. Protoconch, AM C.585921 [SK337]. C–G, O–Q. S. diemenensis. C. Lectotype MNHN-IM-2000-35952. D. Tas, TS, AM C.584797 [SK047]. E. Tas, AM C.585270 [M107]. F. Vic, AM C.585286 [M168]. G. Tas, AM C.585260 [M170]. O. Animal. P. Tas, TS, in situ. Q. Protoconch, Vic, AM C.585357 [SK029]. H–J, R–T. S. australis. H. Lectotype MNHN-IM-2000-5036. I. NZ, Stewart Is, AM C.585249 [M481, SK288]. J. Stewart Is, AM C.585247 [M480, SK289]. K. Holotype of S. inculta USNM 5857. R–S. In situ and animal. T. Protoconch, AM C.265856 [SK511]. L–N. S. capensis. L. Lectotype MNHN IM 2000-38235. M. South Africa, MNHN-IM-2019- 1481 [M585]. N. IM-2019-1477 [M584]. Unlabelled scale bars = 10 mm.