33:
55:
253:, more abundant north to Alaska. Both have oval and chalky-white or yellow shells with patches of brown periostracum (leather-like skin) on the shell. These clams are also commonly called gapers because their shells are flared around the siphon and do not completely close, rather like geoduck clams. Like geoducks, they are unable to completely retract the siphon within the shell, though less flagrantly as the siphon on
338:
soon die if abandoned. The adults are unable to rebury themselves—they need the pressure of their surroundings to remain intact and maneuver. They can't hold their two big valves together, protecting their soft tissues. Responsible diggers carefully rebury them to about the depth at which the clams were found.
337:
Some clammers find horse clams are not as tasty as others, so it's not unusual during clamming season to find horse clams left behind on the beach. The shells are more fragile than they might appear, so it is critical that they not be damaged when first digging if they are not kept. The clams will
300:, often a mating pair, which enter through the large siphon and live within the mantle cavity of the horse clam. The crabs are easily seen and in no way affect the clam as food. The meat is good and makes excellent chowder. They tend to be ignored by sport diggers in Washington but not in Oregon.
286:, normally burying themselves 12–16 inches (30–41 cm), so they are much easier to dig than geoducks. Their preferred substrates are also preferred by butter and littleneck clams, so horse clams are often taken incidentally in commercial harvesting.
269:
usually has relatively longer, narrower shells (longer compared to height) and larger siphonal plates (horny plates found at the tip of the siphon, often with a little algae or barnacles garden). Hence
319:
Appreciated by pre-contact local Native
Americans for their size, abundance, and relatively easy capture, they are less sought today than geoducks, which have gained a marketing cachet.
325:
sets size and bag limits for these clams. The
Department of Health sometimes closes beaches for public health and safety. The Department of Health Marine Biotoxin web site
1594:
1746:
1633:
1756:
1731:
574:
1568:
1607:
1741:
1736:
322:
Identification is important. Best recipes vary with species. For resource sustainability, the
Washington State Department of Fish and Wildlife
1646:
347:
540:
471:
332:
1761:
491:
362:
has revealed use of horse clam shells as a scoop implement. An unusually well decorated specimen was found at the present day town of
282:
Their habitat is the lower intertidal zones on out to waters as deep as 50–60 feet (13–15 m). They prefer sand, mud, and gravel
1698:
388:
1612:
567:
230:), though smaller, with shells up to eight inches long (20 cm), weight to 3–4 lb (1.4–1.8 kg).
1751:
1542:
1370:
283:
1638:
1159:
1134:
1495:
1191:
947:
560:
54:
1452:
1355:
1030:
941:
753:
695:
606:
1510:
1445:
1091:
1058:
658:
543:
by the
Washington State Department of Fish and Wildlife at the King County Department of Natural Resources
359:
176:
1547:
1672:
1405:
1381:
1365:
936:
924:
811:
159:
549:, an overview by Underwater Harvesters Association, British Columbia, developers of underwater farming.
1703:
1086:
989:
914:
786:
748:
685:
621:
381:
1625:
1400:
1186:
400:
32:
1726:
1690:
1106:
1009:
999:
984:
979:
888:
880:
875:
743:
663:
653:
611:
216:
a species which is similar in morphology and lifestyle. Both species are somewhat similar to the
49:
1677:
116:
1599:
1659:
1555:
1438:
1415:
1332:
1218:
1175:
1169:
1140:
1129:
865:
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791:
648:
475:
1664:
1327:
1279:
1229:
1223:
1164:
1101:
994:
930:
730:
637:
222:
212:
495:
1111:
1096:
1081:
1076:
680:
669:
234:
1469:
1410:
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1025:
1004:
919:
855:
835:
510:
426:
1720:
1474:
1375:
1268:
1261:
1181:
1053:
1048:
850:
845:
840:
806:
758:
738:
546:
351:
529:
1560:
1121:
643:
297:
290:
1685:
1620:
1581:
1287:
1014:
894:
870:
801:
781:
763:
700:
675:
227:
1533:
1479:
1319:
1245:
962:
631:
355:
1292:
1235:
1210:
816:
705:
626:
363:
326:
203:
126:
66:
1527:
1484:
589:
293:
106:
96:
86:
233:
The two species commonly known as horse clams inhabit the
Pacific coast
1573:
1342:
1310:
1019:
971:
906:
719:
616:
217:
195:
192:
1586:
1429:
1068:
827:
773:
690:
136:
76:
1504:
1392:
1201:
1151:
1040:
711:
552:
331:
King County has a well-illustrated clam identification procedure
1651:
598:
1508:
556:
358:. For example, archaeological recovery from Chumash sites in
415:(Second Edition), McGraw-Hill Book Company, 1968, at p. 313.
528:, The Megalithic Portal, ed. A. Burnham, February 28, 2008
323:
1517:
1462:
1428:
1391:
1341:
1318:
1309:
1278:
1244:
1209:
1200:
1150:
1120:
1067:
1039:
970:
961:
905:
826:
772:
729:
597:
588:
541:Abbreviated edition of the clam identification key
513:. Washington Department of Fish and Wildlife. 2000
429:. Washington Department of Fish and Wildlife. 2000
303:Horse clams are broadcast spawners like geoducks;
265:An easy way to tell the two species apart is that
289:Horse clams often have a relationship with small
346:Early exploitation of horse clams is known by
568:
494:. Washington State University. Archived from
245:, more abundant south to California; and the
8:
1505:
1315:
1206:
967:
594:
575:
561:
553:
472:"Beach Assessment Clam Identification Key"
31:
20:
492:"At the Beach Now: Horse? Or Gaper Clams"
374:
191:is a species of saltwater clam, marine
547:Science: Geoduck and Horseclam Biology
7:
1747:Western North American coastal fauna
411:G.E. MacGinite & N. MacGinite,
1757:Seafood in Native American cuisine
366:during archaeological excavation.
14:
413:Natural History of Marine Animals
206:. It also shares the common name
1732:Marine molluscs of North America
389:World Register of Marine Species
53:
1:
1742:Molluscs of the United States
1737:Molluscs of the Pacific Ocean
474:. King County. Archived from
470:Brenner, Bob (1998-11-02).
391: on 23 September 2010.
1778:
1762:Bivalves described in 1850
387:. Retrieved through:
342:Prehistorical exploitation
1493:
1077:Black-foot opihi/Hawaiian
328:has current information.
257:species is not as large.
226:, which is in the family
165:
158:
50:Scientific classification
48:
39:
30:
23:
948:Placopecten magellanicus
792:New Zealand green-lipped
524:C. Michael Hogan (2008)
490:Nash, Pat (2004-01-15).
1453:Acanthopleura granulata
1022:(group of four species)
1446:Acanthopleura echinata
1356:Atlantic white-spotted
807:Asian/Philippine green
360:San Luis Obispo County
1673:Paleobiology Database
1382:Amphioctopus fangsiao
1026:South African abalone
898:("true oyster" genus)
664:California butterclam
307:spawns in summer and
278:Habitat and lifestyle
1107:Ribbed Mediterranean
622:Grooved carpet shell
370:Notes and references
1752:Fauna of California
1102:Rayed Mediterranean
696:Japanese littleneck
315:Harvesting for food
1475:Land snail farming
889:Gillardeau oysters
607:Atlantic jackknife
274:is the fat gaper.
198:, common name the
16:Species of bivalve
1714:
1713:
1660:Open Tree of Life
1511:Taxon identifiers
1502:
1501:
1480:Gastropod anatomy
1439:Chiton magnificus
1424:
1423:
1401:New Zealand arrow
1305:
1304:
1301:
1300:
1176:Kelletia lischkei
1141:Littorina sitkana
1087:Yellow-foot opihi
957:
956:
851:Colchester native
184:
183:
1769:
1707:
1706:
1694:
1693:
1681:
1680:
1668:
1667:
1655:
1654:
1642:
1641:
1629:
1628:
1616:
1615:
1603:
1602:
1590:
1589:
1577:
1576:
1564:
1563:
1551:
1550:
1538:
1537:
1536:
1506:
1316:
1230:Chorus giganteus
1207:
968:
931:Pecten jacobaeus
638:Mactra stultorum
595:
577:
570:
563:
554:
521:
519:
518:
506:
504:
503:
486:
484:
483:
458:
455:
449:
446:
440:
437:
435:
434:
422:
416:
409:
403:
398:
392:
379:
348:Native Americans
235:intertidal zones
223:Panopea generosa
213:Tresus nuttallii
202:, in the family
171:
58:
57:
35:
21:
1777:
1776:
1772:
1771:
1770:
1768:
1767:
1766:
1717:
1716:
1715:
1710:
1702:
1697:
1689:
1684:
1676:
1671:
1663:
1658:
1650:
1645:
1637:
1632:
1624:
1619:
1611:
1606:
1598:
1593:
1585:
1580:
1572:
1567:
1559:
1554:
1546:
1541:
1532:
1531:
1526:
1513:
1503:
1498:
1489:
1485:Bivalve anatomy
1458:
1420:
1406:Japanese flying
1387:
1337:
1297:
1274:
1240:
1196:
1146:
1116:
1097:Common European
1063:
1035:
953:
937:Peruvian calico
901:
822:
819:(mussel family)
768:
725:
670:Senilia senilis
584:
583:Edible mollusks
581:
537:
535:Further reading
516:
514:
509:
501:
499:
489:
481:
479:
469:
466:
461:
457:C.M.Hogan, 2008
456:
452:
447:
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438:
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430:
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344:
317:
280:
263:
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52:
17:
12:
11:
5:
1775:
1773:
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1739:
1734:
1729:
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1718:
1712:
1711:
1709:
1708:
1695:
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1669:
1656:
1643:
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1617:
1604:
1591:
1578:
1565:
1552:
1539:
1523:
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1515:
1514:
1509:
1500:
1499:
1494:
1491:
1490:
1488:
1487:
1482:
1477:
1472:
1470:Oyster farming
1466:
1464:
1463:Related topics
1460:
1459:
1457:
1456:
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1442:
1434:
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1426:
1425:
1422:
1421:
1419:
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1413:
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1378:
1373:
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1363:
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1339:
1338:
1336:
1335:
1330:
1324:
1322:
1313:
1307:
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1298:
1296:
1295:
1290:
1284:
1282:
1276:
1275:
1273:
1272:
1265:
1258:
1255:Cornu aspersum
1250:
1248:
1242:
1241:
1239:
1238:
1233:
1226:
1221:
1215:
1213:
1204:
1198:
1197:
1195:
1194:
1189:
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951:
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927:
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868:
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830:
824:
823:
821:
820:
814:
809:
804:
799:
794:
789:
784:
778:
776:
770:
769:
767:
766:
764:Giant Atlantic
761:
756:
751:
746:
741:
735:
733:
727:
726:
724:
723:
716:
708:
703:
698:
693:
688:
686:Triangle shell
683:
678:
673:
666:
661:
656:
651:
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641:
634:
629:
624:
619:
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531:
522:
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487:
465:
462:
460:
459:
450:
441:
417:
404:
401:Beach watchers
393:
373:
371:
368:
343:
340:
316:
313:
279:
276:
262:
261:Identification
259:
182:
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174:
163:
162:
156:
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148:
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99:
94:
90:
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84:
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74:
70:
69:
64:
60:
59:
46:
45:
44:(Gould, 1850)
37:
36:
28:
27:
15:
13:
10:
9:
6:
4:
3:
2:
1774:
1763:
1760:
1758:
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1740:
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1705:
1700:
1696:
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1657:
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1648:
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1640:
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1631:
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1570:
1566:
1562:
1557:
1553:
1549:
1544:
1540:
1535:
1529:
1525:
1524:
1522:
1520:
1516:
1512:
1507:
1497:
1492:
1486:
1483:
1481:
1478:
1476:
1473:
1471:
1468:
1467:
1465:
1461:
1455:
1454:
1450:
1448:
1447:
1443:
1441:
1440:
1436:
1435:
1433:
1431:
1427:
1417:
1414:
1412:
1409:
1407:
1404:
1402:
1399:
1398:
1396:
1394:
1390:
1384:
1383:
1379:
1377:
1374:
1372:
1369:
1367:
1366:Pacific giant
1364:
1362:
1359:
1357:
1354:
1352:
1349:
1348:
1346:
1344:
1340:
1334:
1331:
1329:
1326:
1325:
1323:
1321:
1317:
1314:
1312:
1308:
1294:
1291:
1289:
1286:
1285:
1283:
1281:
1277:
1271:
1270:
1269:Helix pomatia
1266:
1264:
1263:
1262:Helix lucorum
1259:
1257:
1256:
1252:
1251:
1249:
1247:
1243:
1237:
1234:
1232:
1231:
1227:
1225:
1222:
1220:
1217:
1216:
1214:
1212:
1208:
1205:
1203:
1199:
1193:
1190:
1188:
1185:
1183:
1180:
1178:
1177:
1173:
1171:
1168:
1166:
1163:
1161:
1158:
1157:
1155:
1153:
1149:
1143:
1142:
1138:
1136:
1133:
1131:
1128:
1127:
1125:
1123:
1119:
1113:
1110:
1108:
1105:
1103:
1100:
1098:
1095:
1093:
1090:
1088:
1085:
1083:
1080:
1078:
1075:
1074:
1072:
1070:
1066:
1060:
1057:
1055:
1052:
1050:
1047:
1046:
1044:
1042:
1038:
1032:
1029:
1027:
1024:
1021:
1018:
1016:
1013:
1011:
1008:
1006:
1003:
1001:
998:
996:
993:
991:
988:
986:
983:
981:
978:
977:
975:
973:
969:
966:
964:
960:
950:
949:
945:
943:
940:
938:
935:
933:
932:
928:
926:
923:
921:
918:
916:
913:
912:
910:
908:
904:
897:
896:
892:
890:
887:
885:
883:
882:Ostra chilena
879:
877:
874:
872:
869:
867:
864:
862:
859:
857:
854:
852:
849:
847:
844:
842:
839:
837:
834:
833:
831:
829:
825:
818:
815:
813:
810:
808:
805:
803:
800:
798:
795:
793:
790:
788:
787:Mediterranean
785:
783:
780:
779:
777:
775:
771:
765:
762:
760:
757:
755:
752:
750:
747:
745:
742:
740:
737:
736:
734:
732:
728:
722:
721:
717:
715:(razor genus)
714:
713:
709:
707:
704:
702:
699:
697:
694:
692:
689:
687:
684:
682:
679:
677:
674:
672:
671:
667:
665:
662:
660:
657:
655:
654:Pacific razor
652:
650:
647:
645:
642:
640:
639:
635:
633:
630:
628:
625:
623:
620:
618:
615:
613:
612:Atlantic surf
610:
608:
605:
604:
602:
600:
596:
593:
591:
587:
578:
573:
571:
566:
564:
559:
558:
555:
548:
545:
542:
539:
538:
534:
530:
527:
523:
512:
508:
498:on 2006-08-28
497:
493:
488:
478:on 2001-01-21
477:
473:
468:
467:
463:
454:
451:
445:
442:
428:
421:
418:
414:
408:
405:
402:
397:
394:
390:
386:
385:(Gould, 1850)
384:
378:
375:
369:
367:
365:
361:
357:
353:
352:Pacific Ocean
349:
341:
339:
335:
333:
329:
327:
324:
320:
314:
312:
310:
306:
301:
299:
295:
292:
287:
285:
277:
275:
273:
268:
260:
258:
256:
252:
248:
244:
240:
239:pacific gaper
236:
231:
229:
225:
224:
219:
215:
214:
209:
205:
201:
197:
194:
190:
189:
178:
172:
170:
164:
161:
160:Binomial name
157:
153:
152:
151:T. capax
147:
144:
143:
140:
139:
135:
132:
131:
128:
125:
122:
121:
118:
115:
113:Superfamily:
112:
111:
108:
105:
102:
101:
98:
95:
92:
91:
88:
85:
82:
81:
78:
75:
72:
71:
68:
65:
62:
61:
56:
51:
47:
43:
38:
34:
29:
26:
22:
19:
1519:Tresus capax
1518:
1451:
1444:
1437:
1380:
1371:Southern red
1267:
1260:
1253:
1228:
1202:Other snails
1174:
1139:
946:
929:
915:Atlantic bay
893:
881:
846:Southern mud
718:
710:
668:
649:Ocean quahog
636:
525:
515:. Retrieved
500:. Retrieved
496:the original
480:. Retrieved
476:the original
464:Bibliography
453:
444:
431:. Retrieved
420:
412:
407:
396:
383:Tresus capax
382:
377:
345:
336:
330:
321:
318:
308:
304:
302:
298:Pinnixa faba
288:
281:
271:
267:T. nuttallii
266:
264:
254:
250:
246:
243:T. nuttallii
242:
238:
232:
221:
211:
207:
199:
188:Tresus capax
187:
186:
185:
169:Tresus capax
168:
166:
150:
149:
137:
42:Tresus capax
41:
25:Tresus capax
24:
18:
1686:SeaLifeBase
1621:NatureServe
1582:iNaturalist
1416:Neon flying
1122:Periwinkles
1082:Turtle/talc
1015:Green ormer
925:New Zealand
895:Crassostrea
876:Sydney rock
754:New Zealand
676:Smooth clam
644:Blunt gaper
526:Morro Creek
511:"Shellfish"
427:"Shellfish"
311:in winter.
305:T. nuttalii
228:Hiatellidae
40:Siphons of
1721:Categories
1333:Bottletail
1320:Cuttlefish
1280:Freshwater
1224:Korean mud
1187:Pear whelk
963:Gastropods
920:Great/king
866:Windowpane
861:Portuguese
797:California
701:Razor clam
681:Soft-shell
517:2006-08-06
502:2006-08-06
482:2006-08-06
433:2006-08-06
356:California
284:substrates
208:horse clam
117:Mactroidea
1727:Mactridae
1626:2.1133845
1328:Spineless
1192:Lightning
1160:Channeled
817:Mytilidae
706:Pod razor
627:Hard clam
364:Morro Bay
354:coast of
294:pea crabs
291:commensal
247:fat gaper
204:Mactridae
200:fat gaper
145:Species:
127:Mactridae
73:Kingdom:
67:Eukaryota
1600:10229948
1534:Q3016512
1528:Wikidata
1496:Category
1411:Humboldt
1361:Big blue
1219:Mud-flat
1170:Kellet's
1010:Greenlip
1005:Blacklip
907:Scallops
590:Bivalves
439:(2) Nash
309:T. capax
272:T. capax
251:T. capax
123:Family:
107:Venerida
97:Bivalvia
87:Mollusca
83:Phylum:
77:Animalia
63:Domain:
1574:5188976
1430:Chitons
1343:Octopus
1311:Inkfish
1293:Nerites
1182:Knobbed
1069:Limpets
1054:Elegant
1041:Conches
1031:Chilean
972:Abalone
856:Pacific
841:Olympia
836:Eastern
828:Oysters
774:Mussels
731:Cockles
720:Paphies
617:Geoduck
448:Brenner
350:on the
218:geoduck
196:mollusk
193:bivalve
179:, 1850)
133:Genus:
103:Order:
93:Class:
1704:367776
1678:168081
1665:131015
1652:367776
1587:126927
1548:395169
1351:Common
1236:Bailer
1165:Common
1152:Whelks
1135:Banded
1130:Common
1112:Rustic
884:/Bluff
759:Sydney
749:Goolwa
739:Common
691:Tuatua
255:Tresus
237:: the
138:Tresus
1699:WoRMS
1691:47949
1639:31208
1613:80955
1595:IRMNG
1561:584FS
1393:Squid
1376:Mimic
1288:Apple
1092:China
1049:Queen
995:Green
990:Black
980:White
942:Yesso
802:Brown
744:Blood
712:Ensis
659:Venus
632:Horse
599:Clams
424:(1)
210:with
177:Gould
1647:OBIS
1634:NCBI
1608:ITIS
1569:GBIF
1543:BOLD
1246:Land
1020:Pāua
1000:Pink
871:Rock
812:Date
782:Blue
1556:CoL
1211:Sea
1059:Dog
985:Red
1723::
1701::
1688::
1675::
1662::
1649::
1636::
1623::
1610::
1597::
1584::
1571::
1558::
1545::
1530::
334:.
296:,
249:,
241:,
576:e
569:t
562:v
520:.
505:.
485:.
436:.
220:(
175:(
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