Table 1 List of species analyzed in this study and their GenBank accession numbers.

Vetigastropoda

Turbinidae

Angaria delphinus

19,554

NC_031860

Angaria neglecta

19,470

NC_028707

Astralium haematragum

16,310

NC_031858

Bolma rugosa

17,432

NC_029366

Lunella aff. Cinereal

17,670

KF700096

Lunella granulate

17,190

NC_031857

Tegulidae

Tegula brunnea

17,690

NC_016954

Tegula lividomaculata

17,375

NC_029367

Tectus pyramis

18,439

MF138911

Trochidae

Gibbula umbilicalis

16,277

NC_035682

Stomatella planulata

17,151

NC_031861

Umbonium thomasi

15,998

MH729882

Haliotidae

Haliotis discus hannai

16,886

KF724723

Haliotis rufescens

16,646

NC_036928

Haliotis iris

17,131

NC_031361

Haliotis laevigata

16,545

NC_024562

Haliotis rubra

16,907

AY588938

Haliotis tuberculata

16,521

FJ599667

Phasianellidae

Phasianella solida

16,698

NC_028709

Neomphaliones

Bathysciadiidae

Bathysciadiidae sp.

17,238

MH837532

Cocculinidae

Cocculina subcompressa

18,167

MH837536

Peltospiridae

Peltospira smaragdina

15,112

MH837538

Caenogastropoda

Muricidae

Boreotrophon candelabrum

15,265

NC_046505

Ceratostoma burnetti

15,334

NC_046569

Ceratostoma rorifluum

15,338

MK411750

Ocinebrellus falcatus

15,326

NC_046052

Ocinebrellus inornatus

15,324

NC_046577

Concholepas concholepas

15,495

NC_017886

Rapana venosa

15,272

EU170053

Conidae

Conus betulinus

16,240

NC_039922

Conus tulipa

15,756

KR006970

Conus borgesi

15,536

EU827198

Conus capitaneus

15,829

NC_030354

Conus tribblei

15,570

NC027957

Turridae

Turricula nelliae spuria

16,453

MK251986

Naticidae

Euspira gilva

15,315

NC_046593

Euspira pila

15,244

NC_046703

Mammilla kurodai

15,309

NC_046596

Mammilla mammata

15,319

NC_046597

Xenophoridae

Onustus exutus

16,043

MK327366

Pomatiopsidae

Oncomelania hupensis nosophora

15,182

LC276226

Oncomelania quadrasi

15,184

LC276227

Oncomelania hupensis robertsoni

15,188

LC276228

Turritellidae

Turritella bacillum

15,868

NC_029717

Epitoniidae

Epitonium scalare

15,143

MK251987

Neritimorpha

Neritidae

Clithon oualaniense

15,706

MT568501

Clithon retropictus

15,802

NC_037238

Clithon sowerbianum

15,919

MT230542

Neritina usnea (partial genome)

15,574

KU342665

Neritina violacea

15,710

KY021066

Nerita albicilla

15,314

MK516738

Nerita balteata

15,571

MN477253

Nerita chamaeleon

15,716

MT161611

Nerita undata

15,583

MN477254

Nerita versicolor

15,866

KF728890

Nerita fulgurans

15,343

KF728888

Nerita tessellata

15,741

KF728889

Nerita japonica

15,875

MN747116

Nerita yoldii

15,719

MK395169

Nerita melanotragus

15,261

GU810158

Helicinidae

Pleuropoma jana

15,851

KU342666

Patellogastropoda

Acmaeidae

Bathyacmaea nipponica

16,792

MF095859

Nacellidae

Cellana radiata

16,194

MH916651

Nacella clypeater

16,742

KT990124

Nacella magellanica

16,663

KT990125

Nacella concinna

16,761

KT990126

Patellidae

Patella ferruginea

14,400

MH916654

Patella vulgata

14,808

MH916653

Lottiidae

Lottia digitalis

26,835

DQ238599

Lottia goshimai

18,192

MT248298

Nipponacmea fuscoviridis

18,720

MK395167

Heterobranchia

Aplysiidae

Aplysia californica

14,117

AY569552

Aplysia dactylomela

14,128

DQ991927

Aplysia kurodai

14,131

KF148053

Polyceridae

Nembrotha kubaryana

14,395

NC_034920

Roboastra europaea

14,472

NC_004321

Notodoris gardineri

14,424

DQ991934

Siphonariidae

Siphonaria pectinate

14,065

AY345049

Volvatellidae

Ascobulla fragilis

14,745

AY345022

Placobranchidae

Elysia cornigera

14,118

NC_035489

Elysia timida

14,088

NC_035490

Ellobiidae

Auriculastra duplicata

13,920

NC_036959

Auriculinella bidentata

14,135

JN606066

Ovatella vulcani

14,274

JN615139

Onchidiidae

Onchidella celtica

14,150

AY345048

Peronia peronii

13,968

JN619346

Platevindex mortoni

13,991

NC_013934

Pyramidellidae

Pyramidella dolabrata

13,856

AY345054