Williamia radiata ( Pease, 1861 )

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 : 195-199

Williamia radiata ( Pease, 1861)

( Figs 81A–H, J , 80G )

Tectura radiata Pease 1861: 437 (type locality: ‘Sandwich Islands’ [Hawaii]).— Dall 1872: 193; Tryon & Pilsbry 1891: 154; Kay 1965: 29, pl. 11, figs 6–7; Marshall 1981: 488.

Williamia radiata — Melville & Standen 1897: 414; Habe & Kikuchi 1960: 64; Habe 1961: 96, pl. 44, fig. 14; Kay 1979: 493, figs 157 k, l; Marshall 1981: 488; Ruthensteiner et al. 2007: 17, figs 1A–H, 2A–C, 3A–F.

Capulus nutatus Hedley 1908 : pl. 9, figs 15–16 (type locality: around Sydney [NSW, Australia]).— Iredale 1912: 218; Marshall 1981: 488.

Roya kermadecensis Iredale 1912: 218 , pl. 9, fig. 10 (type locality: Sunday Island, Kermadec Group, [ NZ]).— Marshall 1981: 488.

Williamia radiata Kuroda & Habe in Habe 1961: 96, pl. 44, fig. 14 (type locality Japan).— Marshall, 1981: 488 (invalid; secondary junior homonym of Tectura radiata Pease, 1860 ).

Williamia japonica Habe, 1962: 96 (replacement name for Williamia radiata Kuroda & Habe, 1961 not Pease, 1861).— Marshall 1981: 488.

Allerya radiata — Habe, 1964: 144, pl. 44, fig. 14. Marshall, 1981: 488.

Williamia radiata nutata — Marshall 1981: 488, figs 1, 2C, D, F, H, I, K; Brook 1998: 199; Raven & Bracegirdle 2010: 46; Duffy & Ahyong 2015: 67.

Williamia polynesica Rehder 1980: 98 (type locality: off Waikiki, Oahu, Hawaii [ USA]).— Marshall 1981: 488.

Williamia radiata radiata — Marshall 1981: 488, figs 2A, B, L.

Williamia radiata japonica — Habe et al. 1986: 23.

Material examined. Type material. Lectotype of Tectura radiata Pease, 1860 from ‘ Sandwich Islands’ [Hawaii], Cuming Collection, date? ( NHMUK 1962837 ; Fig. 81A ). One paralectotype, same data as lectotype ( NHMUK 1962838 ).

Holotype of Capulus nutatus Hedley, 1908 from Balmoral Beach [Sydney, NSW, Australia]; coll. C.T. Starkey, pre. 1907 ( AM C.029106 ; Fig. 81B ). Twelve paratypes, same data as holotype ( AM C.143080 ; Fig. 81C largest paratype).

Holotype of Roya kermadecensis Iredale, 1912 from Sunday Island, Kermadec Group ( CM M.5464 ; Fig. 81D ).

Holotype of Williamia polynesica Rehder, 1980 from off Waikiki, Oahu , Hawaii ( USNM 757897 ; Fig. 81E ).

Other, non-type material. NZ: Kermadec Ids, Raoul (Sunday) Is 29°15’S, 177°52’W ( AM C.30230 8d); 4kms N of Cape Rodney, 36°15’S, 174°49’E ( AM C.110823 4d); Off Poor Knights Islands 35°28.3’S, 174°44.13’E ( NMNZ M.100391/1 p [M601, SK555]). NC: Loyalty Is, Lifou Is ( AM C.25728 2d; AM C.335728 d) . PNG: Ella Beach , Port Moresby, 9°29’S, 147°9’E ( AM C.335729) . Australia: Coral Sea, Northeast Herald Cay, 16°56’S, 149°11’E ( AM C.335727). Elizabeth Reef , 29°57.2’S, 159°1.18’E ( AM C.336005 d), 29°54.78’S, 159°2.78’E ( AM C.336013d), 29°54.78’S, 159°2.78’E ( AM C.336015 d); Middleton Reef , 29°23.93’S, 159°6.7’E ( AM C.461846 d), 29°24.02’S, 159°6.2’E ( AM C.461845 p), 29°24’S, 159°5.16’E ( AM C.461844 d), 29°24.03’S, 159°4.37’E ( AM C.461843 d). NI: 29°2’S, 167°57’E ( AM C.59405 p [SK006]). Qld : Michaelmas Cay , 16°36’S, 145°59’E ( AM C.110822 2d); SW side Euston Reef , 16°40’S, 146°13’E ( AM C.335730 9d); Bunker Group , Lady Musgrave Is , 23°54’S, 152°25’E ( AM C.398297 d). Caloundra , 26°49’S, 153°10’E ( AM C.335994 d). LHI: 31°46.55’S, 159°13.4’E ( AM C.461858 d), 31°32.5’S, 159°3.75’E ( AM C.59697 d). NSW: Angourie Point , 29°29’S, 153°22’E ( AM C.112574 2d); Clarence River (mouth), 29°25.5’S, 153°21’E ( AM C.110824 5d); Woolgoolga , 30°6.7’S, 153°12.3’E ( AM C.110818 2d); Point Halliday , 32°4.5’S, 152°33’E ( AM C.117308 2d, AM C.336021 4d); North Fingal Bay , 32°44.75’S, 152°10.5’E ( AM C.110814 11d, AM C.117310 d); Port Stephens , 32°42’S, 152°5’E ( AM C.110812 5d, C.595937 p [SK562]); Sydney , Balmoral Beach , Middle Harbour , 33°49.7’S, 151°15.02’E ( AM C.143080 12d,AM C.29106 d); Coogee Bay , 33°55.5’S, 151°15.4’E ( AM C.110813 2d); Kurnell , Botany Bay , 33°57’S, 151°12.37’E ( AM C.107325 8d, AM C.110817 d, AM C.117309 d, AM C.112575 19d); Bate Bay , Cronulla Beach , 34°2.5’S, 151°10’E ( AM C.110815 2d). Shell Harbour , 34°35’S, 150°52’E ( AM C.398294 d); Gerringong , 34°44.28’S, 150°50’E ( AM C.110816 d); Ulladulla , 35°21.5’S, 150°28.5’E ( AM C.398293 d); Twofold Bay , 37°5.11’S, 149°55.35’E ( AM C.50019 d). Tas : Flinders Island , Fotheringate Beach , 40°12.948’S, 148°2.106’E ( TMAG E36516 d, TMAG E36516 p). WA: Turtle Beach, W side of North West Cape , 21°48’S, 114°10’E ( AM C.110825 d); North West Cape , 21°49’S, 114°11’E ( AM C.110821 2d); Point Quobba, N of Carnarvon, 24°29’S, 113°25’E ( AM C.398298 d); Off Chinaman’s Bluff, Kalbarri, 27°42’S, 114°9’E ( AM C.336007 d); South of Cowaramup , 33°53’S, 114°59’E ( AM C.110820 d) .

Taxonomic remarks. The lectotype of Tectura radiata has been designated by Kay (1965). The name W. radiata Kuroda & Habe, 1961 (in Habe 1961) is a junior secondary homonym of W. radiata ( Pease, 1861) . Habe (1962: 96, pl. 44, fig. 14) introduced W. japonica as a replacement name (Art. 12.2 of the Code). Subsequently, Habe (1964: 144) treated Williamia japonica as a junior synonym of W. radiata , which was confirmed by Marshall (1981: 488). Marshall (1981) recognised two geographic subspecies; W. radiata radiata ( Pease, 1861) and W. radiata nutata (Hedley, 1908) , but suspected that both taxa would ‘ultimately prove to be synonyms ’.

External morphology (preserved). Animal evenly dark yellowish, black pigmentation absent; foot wall and mantle narrow, mantle edge thickened unlobed, singular cephalic fold, wide, front wide, striated, 2 black eye spots separately located within cephalic fold ( Fig. 80G ).

Shell ( Figs 81A–H, J ; Table S9). Circular ovate, small sized (max sl mean = 6.7 mm, SD = 0.8 mm, n = 8), tall, shell thickness thin; exterior smooth, evenly yellowish brown, growth striae indistinct; apex offset weakly posterior and central, lateral and anterior apical sides strongly convex, posterior side concave, protoconch below shell apex, direction weakly heterostrophic (n = 1, Fig. 81J ), shell whorl dextral; ribs pale axial bands, fairly straight, increasingly broaden to shell lip, periostracum extends beyond uncorrugated shell edge. ribs unraised, rib count (mean = 24, SD = 1.9, n = 8), Interior paler than exterior. ADM circular and complete ( Figs 81D, F ), thinner over siphonal opening and CMS.

Reproductive system ( Fig. 80G; n = 1). Positioned within coelom under the respiratory cavity, epiphallic parts ( AO, EG, ED, F1) positioned over and behind BM, hermaphroditic complex ( HG, AG and MG) to posterior against right foot wall under intestine and over foot sole; singular GP positioned immediately behind right side of cephalic fold; ED long wide, joins to lower side of small GA, AO indistinct; EG large, soft, folded, flagellum (F1) indistinct; BD and CD jointly connect to side of GA, CD passes between foot wall and outside RAM, CD short wide flat, passes on inner side of RAM, both BD and CD connect into folds of AG and MG; BC medium spherical embedded under MG; HD long, broad, unfolded, links AG to smaller HG; MG and AG folded, soft white tissue.

Comparative remarks. Throughout the known range of W. radiata no sympatric congener has been recorded. The shells figured in Kay (1979: figs 157K–L), Marshall (1981: fig. 2B, D, F) correspond well with shells figured herein ( Figs 81B–H ) as well as the lectotype figured in Kay (1965: pl. 11, figs 6, 7; Fig. 81A herein). The circular and complete ADM scar ( Fig. 81F ) corresponds well with the scar figured in Iredale (1915: pl. 9, fig. 10) as ‘ Roya kermadecensis ’ from Sunday Is, Kermadecs. The figured horseshoe shaped ADM scar of Williamia in Hubendick (1946: fig. 9) is incorrect. The RS of ‘W. radiata’ described and figured in Ruthensteiner et al. (2007: figs 1A–C) corresponds well with that figured herein ( Fig. 80G ). The record of Roya sp. in Powell (1934: 155) likely refers to W. radiata .

Distribution and habitat. Recorded from Kermadec Islands, NZ, NC, PNG, Indian Ocean, E and SW Australia ( Fig. 83 ) in subtidal depths.

Figures

FIGURE 80. Reproductive morphology of S. vudaensis sp. nov., S. waikoloaensis sp. nov., S. yagasaensis sp. nov., Williamia radiata and Williamia sp. ‘Walters Shoal’. A–B. Holotype of S. vudaensis sp. nov. AM C.584785 [SK119]. C–D. Holotype of S. waikoloaensis sp. nov. AM C.584907 [M295, SK214]. E–F. Holotype of S. yagasaensis sp. nov. AM C.584827 [M437 SK226]. G–H. Williamia radiata. G. NZ, Poor Knights Is, NMNZ M.100391/1 [M601, SK555], reproductive organs and animal anterior. H. Walters Shoal, MNHN IM 2013-67370 [M567, SK556], reproductive organs, animal anterior, detail of epiphalic parts. Unlabelled scale bars = 1 mm.

FIGURE 81. Shells if Williamia radiata. A–H, J. W. radiata, A. Lectotype of Tectura radiata NHMUK 1962837. B. Holotype of Capulus nutatus AM C.029106. C. Paratype of C. nutatus AM C.143080. D. Holotype of Roya kermadecensis CM M.5464. E. Holotype of W. polynesica USNM 757897. F. NSW, Botany Bay, AM C.112575. G. NZ, Poor Knights Is, NMNZ M.100391/1 [M601, SK555]. H. NZ, Kermadec Is, AM C.110819. J. NSW, Port Stephens, AM C.595937 [SK562], protoconch. I. Walters Shoal, MNHN IM-2013-67370 [M567, SK556]. Unlabelled scale bars = 10 mm.

FIGURE 83. Radula morphology of S. diemenensis, S. denticulata, S. restis sp. nov. and S. tasmanica. A–D. S. diemenensis, Tas, Recherche Bay, AM C.201772. A. Inner central area x256. B. central area x585. C. Outer laterals x256. D. Shell. E–H. S. denticulata, NSW, Sydney, AM C.315783 x520. E. Inner central area. F. Central area. G. Outer laterals. H. Shell. I–L. S. restis sp. nov. WA, Rottnest Is, AM C.320123. I. Inner central area x234. J. Central area x466. K. Outer laterals x466. L. Shell. M–P. S. tasmanica, Tas, Eaglehawk Neck, AM C.311615. M. Inner central area x505. N. Central area x505. O. Outer laterals x650. P. Shell. Unlabelled scale bars 1 mm.