Siphonaria jeanae Jenkins, 1984

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 : 136-139

Siphonaria jeanae Jenkins, 1984

( Figs 52G–I, Q–S , 53A–B )

Siphonaria (S.) jeanae Jenkins 1984: 114 , pls. 1a–j, 2a–i, figs 1, 2 (type locality: Near boat wharf, Ceduna, SA [ Australia]).— Johnson & Black 1984b: 1371; Grant & Utter 1988: 283; Campton et al. 1992: 255; Vadopalas et al. 2004; 693, 703; White & Dayrat 2012: 64.

Siphonaria sp. — Johnson & Black 1984a: 295.

Material examined. Type material. Holotype of S. jeanae from near boat wharf, Ceduna , SA; coll. B.B. Collette and J.R. Paxton, 4 Feb 1970 ( AM C.123712 , Fig. 52G ); 23 paratypes; same data as holotype ( AM C.123713 3p, 4d; SAM D.16383 6p); Neptune Bay , SA ( MV F15260 5p); Radar Reef, Rottnest Island , WA coll. R. Black, 4 Aug 1979 ( WAM 1798–83 5d).

Other, non-type material. Australia, Vic: Bastion Head Mallacoota, 37°34.429’S, 149°45.927’E, V09- 1 ( AM C.585360 p); Cape Conran, 37°48.798’S, 148°43.608’E, V08-2 ( AM C.585727 9p); Cape Schanck, 38°29.951’S, 144°53.369’E, V06-4 ( AM C.585609 4p); Point Lonsdale (nr Queenscliff), 38°17.276’S, 144°36.977’E, V05-1 ( AM C.585440 10+p, C.585288 p [M102]); Loutit Bay Lorne, 38°31.190’S, 143°59.429’E, V03-2 ( AM C.585434 10+p, C.585285 p [M103]); Crofts Bay , 38°35.363’S, 142°50.633’E, V01-3 ( AM C.585649 5p); Armstrong Bay , 38°21.012’S, 142°21.633’E, V01- 2 ( AM C.585571 3p) . Tas: Park Beach Dodges Ferry, 42°51.716’S, 147°36.665’E, T03-4 ( AM C.585263 p [M108]); Haleys Beach Gibson Peninsula , 32°45.084’S, 134°05.490’E, SA03-4 ( AM C.585207 p [M101]). SA: Cape Northumberland , 38°03.503’S, 140°40.378’E, SA15-1 ( AM C.585547 20+p, C.585219 p [M203], C.585220 p [M204]), Port MacDonnell , 38°03.308’S, 140°39.398’E, SA15-2 ( AM C.585546 20+p, C.585221 p [SK017], C.585222 p [M202]); Cape Thomas , 37°04.461’S, 139°44.659’E, SA14-1 ( AM C.585545 20+p, C.585217 p [M201]); Fisheries Bay , Lands End , 35°37.999’S, 138°06.921’E, SA13-2 ( AM C.585567 3p); Groper Bay nr West Cape , 35°14.108’S, 136°49.883’E, SA10-1 ( AM C.585484 19p, C.585214 p [SK011]); Pondalowie Bay , 35°13.989’S, 136°49.892’E, SA10- 2 ( AM C.585425 10+p); Fishery Bay , Cape Wiles , 34°55.107’S, 135°41.086’E, SA05-1 ( AM C.585709 8p); Port Neill , 34°07.102’S, 136°21.271’E, SA06-1 ( AM C.585424 10+p, C.585213 p [SK012]); Port Moonta , 34°03.273’S, 137°33.592’E, SA09-1 ( AM C.585711 8p); Salmon Point , 33°38.547’S, 134°51.916’E, SA04-2 ( AM C.585537 20+p); ESE of Pt Lincoln , Dangerous Reef , 32°49.05′ S, 136°13.05’E AM C.595961 4p) Wellesley Point , 33°38.483’S, 134°51.963’E, SA04-1 ( AM C.585544, 20+p, C.585212 p [M123]); Haleys Beach Gibson Peninsula , 32°45.084’S, 134°05.490’E, SA03-4 ( AM C.585441, 10+p, C.585207 d, C.585211 p [M122]); Rocky Point , 32°12.250’S, 133°14.861’E, SA02-4 ( AM C.585472,16p); Cedunanearboatwharf , 32°8’S, 133°41’E ( AM C.123712 d, AM C.123713 4 d, 13p); Port Le Hunte Point Sinclair , 32°05.681’S, 132°59.299’E, SA02-1 ( AM C.585419 10+p), 32°05.554’S, 132°59.476’E, SA02- 2 ( AM C.585420 10+p); Cactus Beach , Point Sinclair , 32°05.135’S, 132°58.943’E, SA02-3 ( AM C.585439 10+p, C.585209 p [M121]); Wandrilla Beach , nr Cape Nuyts , 32°01.894’S, 132°16.052’E, SA01-1 ( AM C.585418 10+p). WA: Alexander Bay 2 33°53.467’S, 122°44.995’E, WA64-4 ( AM C.584775 5p, WAM S74133 5p); Alexander Bay , 33°53.374’S, 122°44.922’E, WA64-3 ( AM C.584715 5p, WAM S74132 5p); Salmon Beach Esperance , 33°53.254’S, 121°50.381’E, WA64- 2 ( AM C.584685, 2p, WAM S74131 2p); Bremer Bay Boat Harbour 34°25.613’S, 119°23.818’E, WA63-2 ( AM C.584772, 5p, WAM S74130 5p); Point Henry 34°28.177’S, 119°21.708’E, WA63-1 ( AM C.584771, 5p, C.585313 p [M027], WAM S74129 5p); Cape Riche 34°36.213’S, 118°45.401’E, WA62-5 ( AM C.584713, 5p, WAM S74128 5p); Lookout Point Point Gardner 34°53.449’S, 118°25.397’E, WA62-4 ( AM C.584770, 5p, WAM S74127 5p); Cave Point 35°06.965’S, 117°54.080’E, WA62-1( AM C.584767, 5p, WAM S74125 5p); Whaling Cove 35°03.372’S, 117°55.598’E, WA62- 3 ( AM C.584769, 5p, WAM S74126 5p); Peaceful Bay ; 35°02.989’S, 116°55.769’E, WA60-8 ( AM C.584746, 15p, WAM S74122 5p), 35°02.865’S, 116°55.722’E, WA60-7 ( AM C.584745, 15p, WAM S74121 5p); Wilson Head Ocean Beach 35°02.250’S, 117°19.894’E, WA61- 1 ( AM C.584766, 5p, WAM S74124 5p); Augusta 34°20.451’S, 115°10.069’E, WA60-5 ( AM C.584778, 5p, WAM S74120 5p); Sarge Bay Cape Leeuwin 34°22.091’S, 115°08.820’E, WA60-4 ( AM C.584728, 5p, WAM S74119 5p); Point Dalling Dunsborough 33°35.955’S, 115°06.315’E, WA59-4 ( AM C.584777, 5p, C.585312 p [M130], WAM S74116 3p); Point Casuarina Bunbury 33°18.544’S, 115°38.201’E, WA59-3 ( AM C.584686, 2p, WAM S74115 3p); groyne nr Robert Point Mandurah 32°31.270’S, 115°42.409’E, WA59-1 ( AM C.585577, 3p); Fremantle Hbr breakwater 32°03.342’S, 115°43.987’E, WA58-5 ( AM C.584765, 5p, WAM S74114 5p); Quinns Rock 31°39.822’S, 115°41.345’E, WA58-4 ( AM C.584671, 3p, WAM S74113 2p) ; Rottnest Is: Longreach Bay point, 31°59.333’S, 115°32.063’E RI01( AM C.585757, 3p, C.585820 p [SK215]); Radar Reef, 32°S, 115°18.72’E ( AM C.595962, 10+p); W end Thomson Bay , 32°S, 115°32’E ( AM C.320123 8p); Strickland Bay , 32°S, 115°30’E ( AM C.595963 10+p). Cape Leschenault , 31°17.508’S, 115°27.089’E, WA58-3 ( AM C.584726 6p, WAM S74112 6p); Grey , 30°39.968’S, 115°08.072’E, WA58-2 ( AM C.584670 1p, WAM S74111 2p); Jurien Bay , 30°17.244’S, 115°02.482’E, WA58-1 ( AM C.584695 3p, WAM S74110 2p); Bunker Bay , 33°32.300’S, 115°01.951’E,WA60-2( AMC.58474715p,WAMS74118 5p); Yallingup, 33°38.358’S, 115°01.481’E, WA60-9 ( AM C.584779 7p, WAM S74123 5p); Sugarloaf Rock Cape Naturaliste, 33°33.536’S, 115°00.467’E, WA60-1 ( AM C.584700 3p, WAM S74117 4p); Cowaramup Point, 33°51.934’S, 114°58.904’E, WA60-3 ( AM C.585520 2p); Freshwater Point, 29°36.256’S, 114°58.464’E, WA57- 3 ( AM C.584762 5p, WAM S74107 5p); Cambawarra Head Green Head, 30°04.136’S, 114°57.830’E, WA57- 6 ( AM C.584764 5p, WAM S74109 5p); Illawong, 29°42.254’S, 114°57.542’E, WA57-5 ( AM C.584763 5p, WAM S74108 5p); S end Leander Point Port Denison , 29°16.725’S, 114°54.918’E, WA57-2 ( AM C.584761 5p, WAM S74106 5p); Leander Point Port Denison , 29°16.568’S, 114°54.858’E, WA57-1 ( AM C.584759 5p, WAM S74105 5p); Cape Burney Geraldton, 28°52.084’S, 114°38.056’E, WA54-1 ( AM C.584757 5p, WAM S74104 5p); Horrocks, 28°21.469’S, 114°24.751’E, WA53-1 ( AM C.584780 6p, WAM S74103 6p); Chinamans Rock Kalbarri, 27°42.776’S, 114°09.361’E, WA52-1 ( AM C.584742 12p, WAM S74102 8p) .

Taxonomic remarks. Our delineation of this species is informed by comparative analyses of the morpho-anatomy and mitochondrial genetics of freshly collected topotypes ( Fig. 52H–I ; Table S1).

External morphology ( Fig. 52S ). Foot sole evenly dark grey; foot wall darker than sole with evenly dispersed subepithelial pustules, paler to foot edge; fringing mantle narrow translucent at foot wall gradually becoming opaque with a thickened paler band at the unlobed mantle edge; genital pore inconspicuous, located on foot wall to right anterior of right cephalic fold; two small black epithelial eye spots centralised on two thick centrally touching dark grey cephalic folds; thin pale grey pneumostomal lobe part of the mantle, between the right ADMs, closes the pneumostome and anus at the mantle edge.

Shell ( Figs 52G–I, Q–S ; Table S9). Small sized (max sl mean 8.7 mm, SD = 1.7 mm, n = 10), ovate; height medium, slightly broader posteriorly; thickness thin; apex offset posterior and left; apical sides convex; protoconch direction heterostrophic (n = 3; Fig. 52Q ), shell whorl dextral; siphonal ridge is indicated externally by two broad juxtaposed radial ribs on the right side of the shell. These siphonal ribs don’t project beyond the shell lip. Growth striae may be regular and indistinct ( Jenkins, 1984: pl.1a, d, g) or more commonly irregular and coarse ( Jenkins, 1984: pl. 2a, c, e). This variation in growth striae, only apparent in specimens from Ceduna SA, may be due to differences in habitat exposure, compared to most locations where S. jeanae occurs, Ceduna is sheltered. The radial ribbing is flat and unraised with irregular, pale blue-grey ribs and narrower brown interstices, both of which narrow and curve ad-apically, rib count (mean = 27, SD = 3.8, n = 10), variable as is rib width ( Jenkins, 1984: pl. 1a–i). The shell interior is smooth and glossy with a white to pale blue spatula. Between the thin, purplish grey ADM scar and the spatula, the interior is purplish brown. The siphonal groove is shallow and straight. The brown to grey outer lip is thickened and unsculptured with white radial bands corresponding with exterior radial ribs. Most specimens from south-western Australia have eroded exteriors, irregular growth striae and thickened shell lips ( Jenkins, 1984: pl.2a, c, e).

Reproductive system ( Fig. 53A; n = 2). HG (ovotestis), AG / MG complex located in posterior region of coelom, against inner foot wall and under the respiratory system; HG large, yellow, granular, joined to anterior of the soft white translucent semicircular folds of smaller AG by a short pink lobed HD; HD passes through folds of AG / MG complex. SV small ovate pinkish, embedded in anterior of AG / MG complex, connected via a short thin duct to the junction of the HD and emerging CD. BC small and embedded in folds of MG / AG close to SV. BD and CD long, thin, white, smooth, non-looped, featureless, pass together through the ADM and both enter adjacently into the GA. BC small, brown, appears spherical when holding SPM but deflated when empty. ED long, thick, white and may be centrally looped ( Jenkins, 1984: fig 1b), enters the GA almost opposite the BD and CD juxtapose points of entry. No accessory organ present; EG, cream, soft, lobed, longer than ED, situated to the right posterior of the BM; Single flagellum, F1 short, white, branching from the junction of the EG and ED. GP small, opens from the GA through the foot wall, under the mantle and posterior to the right cephalic fold.

Spermatophore ( Fig. 53B ) (original description in Jenkins, 1983: 115). Short, bulbous (length = 5.5 mm ± 0.14 mm, n = 2); body cylindrical, weakly bulbous; test thin, white opaque core, short tapering section merging head with filamentous flagellum; head bluntly rounded, shorter thinner than translucent flagellum (head length = 2.15 ± 0.07 mm; ~ 39% of SPM length; head width = 200 ± 40 μm, flagellum width = 50 ±10 μm, n = 2); 4 SPMs tightly coiled in BC of one specimen ( AM C.585820) .

Radula and jaw (original description in Jenkins, 1984: pl. 2 g, h, i). The radula has a typically siphonariid morphology; a central tooth with an individually variable number of mid and outer lateral teeth arranged in longitudinal rows. The mean dentition formula is 25:1:25 (n = 3, SD = 2.6) with about 95 transverse rows ( SD = 5.3). These rows are parallel and weakly curved (anteriorly convex). One central tooth is present and of the 25 half row laterals, 10.5 ( SD = 1.2) are mid and 14.5 ( SD = 2.1) outer lateral teeth means respectively. All teeth are weakly concave posteriorly. The central tooth is narrow with a short, pointed mesocone ( Jenkins 1984: pl. 2g, h) with a lower profile than the flanking laterals. Inner laterals characterised by having no side denticles, are absent. The central tooth’s base is narrow in the mid-section with an anterior cleft and a posterior notched point providing interlocking articulation with adjacent central teeth. Bases of the mid lateral teeth interlock posteriorly and anteriorly. The mesocones of the inner 5–7 mid laterals frequently wear a hole in the back of the tooth in front ( Jenkins, 1984: pl. 2i). Outer laterals do not interlock between transverse rows. The spaces between rows increases to the ribbon edges coupled with a gradual decrease in tooth size. The mid lateral teeth are broad based and elongated without flanking ectocones (outer side denticles). The outer lateral teeth have both ecto and endo cones and a squared flat mesocone. The mid lateral’s mesocone can be either pointed or bicuspidate. Of the 3 radulae examined, 2–4 of the inner (mean = 2.66, SD = 1.2) and invariably 2 of the outer mid laterals were bicuspidate, while the central 3–7 mid laterals (mean = 5.66, SD = 2.3) were pointed ( Jenkins, 1984: pl. 2h, i).

Comparative remarks. In our molecular phylogeny, S. jeanae ( lateralis group, unit 75) represents a well-differentiated lineage ( Figs 1 , 4 ). It is the sister species of a clade formed by S. australis , S. propria and S.diemenensis . Siphonaria jeanae differs from other species by COI distances of ≥ 16.6% (Table S8). Throughout its range, S. jeanae has been found in sympatry with seven congeners. Two congeners are sympatric in SE to SW Australia: For comparisons with S. stowae and S. tasmanica refer to comparative remarks under these species. Three species are sympatric in SE Australia: For comparisons with S. funiculata , S. diemenensis , and S. zelandica refer to comparative remarks under these species. One species is sympatric in western WA: Siphonaria restis sp. nov. has a lower, paler off-white coloured shell with greater uneven ribbing and scalloped edge, a paler, golden-brown spatula, a larger AO and BC, and longer ED and F1. RS ( Fig. 53A ) and SPM ( Fig. 53B ) depicted here correspond well with the original description of Jenkins (1984).

Distribution and habitat. Endemic to southern coasts of Australia, from Cape Conran Vic, near Hobart, Tas, SA and to Kalbarri, WA ( Fig. 51 ). In this study, commonly found in exposed and sheltered positions (in crevices, holes) on moderately exposed to exposed intertidal marine rocky shores, upper and mid littoral levels ( Fig. 52R ).

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 51. Known occurrence records of S. alba, S. asghar, S. propria, S. jeanae, S. emergens, S. oblia and S. campestra sp. nov.

FIGURE 52. Shells of S. propria, S. jeanae, S. emergens and S. oblia. A–D, M–N. S. propria. A. Holotype NMNZ M.77363. B–N. NZ, N Island, NMNZ M.331452. B. [M509]. C. [M510]. D. [M511]. M. Protoconch [M514]. N. In situ. E–F, T. S. emergens. E. Holotype AM C.532860. F. Paratype AM C.265919. T. Protoconch, AM C.265919. G–I, Q–S. S. jeanae. G. Holotype AM C.123712. H. Vic, Point Lonsdale, AM C.585288 [M102]. I. WA¸ Point Dalling, AM C.585312 [M130]. Q. Protoconch, AM C.585213 [SK012]. R. WA¸ Point Dalling, in situ. S. WA¸ Point Dalling, animal. J–L, O–P. S. oblia, J. Qld, AM C.585755 [M105]. K. Qld, Cape York, AM C.584902 [M042]. L. Qld, Cape Kimberley, AM C.585505 [SK392]. O–P. Qld, Cape Kimberley, animals, in situ. Unlabelled scale bars = 10 mm.

FIGURE 53. Reproductive morphology of S. jeanae, S. campestra sp. nov., S. camura sp. nov., S. caubianensis sp. nov and S. christmasensis sp. nov. A–B. S. jeanae, WA, Rottnest Is, AM C.585820 [SK215]. C–D. Holotype of S. campestra sp. nov., Timor- Leste, Dili, AM C.584823 [M447, SK230]. E–F. Holotype of S. camura sp. nov., Okinawa, Tancha Bay, AM C.585614 [M491, SK310]. G–H. S. caubianensis sp. nov., Philippines, Polillo Is, WAM S113803 [M600, SK557]. I. Holotype of S. christmasensis sp. nov., CI, Flying Fish Cove, AM C.595957 [M298]. J. CI, AM C.585321 [SK083]. Scale bars = 1 mm.