721:. The deep blue, by-the-wind sailors that are recognized by many beach-goers are the polyp phase of the life cycle. Each "individual" with its sail is really a hydroid colony, with many polyps that feed on ocean plankton. These are connected by a canal system that enables the colony to share whatever food is ingested by individual polyps. Each by-the-wind sailor is a colony of all-male or all-female polyps. The colony has several different kinds of polyps, some of which are both feeding and reproductive, called
773:
622:
55:
33:
812:, while at the same time, other authors favored again placing them in the Anthomedusae/Athecatae. Most authors in the past 40 years have accepted interpretation of these animals as unusual floating colonial athecate hydroids, which produce medusae clearly belonging in the Anthomedusae. Although the exact position of the family Porpitidae within the Athecatae/Anthomedusae is not yet clear, the order
686:
674:
north and moving south over several weeks' time. In some years, so many animals are left at the tide line by receding waves, that the line of dying (and subsequently rotting) animals may be many centimetres deep, along hundreds of kilometres of beaches. Mass strandings have been reported also on the west coast of
Ireland, and in
611:
559:
Each apparent individual is a hydroid colony, and most are less than about 7 cm long. They are usually deep blue in colour, but their most obvious feature is a small stiff sail that catches the wind and propels them over the surface of the sea. Under certain wind conditions, they may be stranded
673:
is at the mercy of prevailing winds for moving around the seas, and are thereby also subject to mass-strandings on beaches throughout the world. For example, a mass stranding occurs most years in the spring along the West Coast of North
America, from British Columbia to California, beginning in the
804:. The systematic position of these peculiar genera has long been a topic of discussion among taxonomists who work with pelagic Cnidaria. The three genera were put in with athecate hydroids in the mid-to-late 19th century by some, whereas other authors at the time included them in the
755:
are rarely captured in the plankton and very little is known about their natural history. The medusae develop to sexual maturity within about three weeks in the laboratory and their free-spawned eggs and sperm develop into a planktonic larva called a
599:
s nematocysts are relatively benign to humans, although each person may respond differently to contact with the nematocyst toxin. It is wise to avoid touching one's face or eyes after handling
595:
in their nematocysts are effective against their prey. While cnidarians all possess nematocysts, in some species the nematocysts and toxins therein are more powerful than other species.
665:
sails always align along the direction of the wind where the sail may act as an aerofoil, so that the animals tend to sail downwind at a small angle to the wind. Having no means of
1350:
747:
organisms typically also found in corals and some sea anemones, that can utilize sunlight to provide energy to the jellyfish. Curiously, although a healthy captive
1389:
1507:
1149:
1492:
1502:
1324:
1497:
1363:
987:
1415:
1487:
646:
lives in warm and temperate waters in all the world's oceans. They live at the water/air interface, with the float above the water, and
1311:
1024:
949:
929:
1069:
1454:
887:
177:
1185:
498:(widely distributed) free-floating hydrozoan that lives on the surface of the open ocean. It is commonly known by the names
1368:
1376:
860:
1109:"Siphonophora of the Indian Ocean: Together with Systematic and Biological Notes on Related Specimens from Other Oceans"
650:
hanging down about a centimetre below. Organisms that live partly in and partly out of the water like this are known as
1140:
1272:
1259:
1153:
1394:
718:
495:
1160:
54:
530:
638:
751:
will release many medusae under the microscope, and are expected to do the same in the sea, the medusae of
1199:
772:
1277:
739:), each about 1 mm high and wide, over several weeks. The tiny medusae are each provided with many
156:
133:
854:
1459:
1298:
1246:
1237:
1042:
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875:
729:
621:
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833:
186:
49:
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945:
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is part of a specialised ocean surface community that includes the better-known cnidarian
477:
1251:
1264:
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805:
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740:
173:
106:
32:
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1108:
813:
809:
697:
526:
116:
1090:
Anthomedusae/Athecatae (Hydrozoa, Cnidaria) of the
Mediterranean. Part I. Capitata
962:
1441:
1381:
1337:
1231:
693:
685:
1222:
1168:
808:. A new order was established for these genera by Totton, in 1954, called the
588:
541:
485:
911:. Wagner Publishing Company, USA (see pages 138 and 144 in the 1942 edition)
1316:
1124:
722:
584:
534:
66:
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The small rigid sail projects into the air and catches the wind. However,
1407:
1216:
1178:
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679:
603:, and itching may develop on parts of the skin that have been exposed to
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522:
481:
96:
86:
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1329:
859:. Paris, France: by the author and Deterville. p. 555 – via
732:
651:
537:
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of hydroids that live floating free at the surface of the open ocean:
1342:
988:"Uncovering the Neuston, a Mysterious Living Island of Sea Creatures"
940:
Branch, G.M., Branch, M.L, Griffiths, C.L. and
Beckley, L.E. (2010).
793:
76:
1193:
735:, so that each Velella colony produces thousands of tiny jellyfish (
771:
684:
675:
620:
610:
609:
592:
561:
1303:
1420:
572:
1197:
963:"By-the-wind-sailors: Creatures wash up on Guernsey beaches"
792:
The
Porpitidae is a family of the Hydrozoa erected for two
942:
Two Oceans: a guide to the marine life of southern Africa.
728:
The gonozooids each produce numerous tiny jellyfish by an
1150:"Billions of Blue Jelly Fish Wash Up on American Beaches"
1040:
Delap, M. J. (1921). "Drift on the Kerry coast".
1070:"'Thousands' of jellyfish-like creatures swamp beach"
654:. Offshore boaters sometimes encounter thousands of
1206:
1092:. Fauna e Flora del Golfo di Napoli. Vol. 39.
1083:
1081:
1079:
540:prey on these cnidarians. Such predators include
725:, and others protective, called dactylozooids.
816:is no longer used by hydrozoan systematists.
8:
717:has a bipartite life cycle, with a form of
1194:
31:
20:
845:
760:, which develops into a new floating
583:that hang down in the water and bear
7:
944:Cape Town:Struik Nature. page 188.
1508:Taxa named by Jean-Baptiste Lamarck
1190:Short documentary films and photos
1175:"Millions of jelly creatures land"
856:Système des animaux sans vertèbres
692:(by-the-wind sailors) stranded on
571:are carnivorous. They catch their
488:family. Its only known species is
14:
1493:Cnidarians of the Atlantic Ocean
888:World Register of Marine Species
53:
1503:Cnidarians of the Pacific Ocean
1169:Marine Life Information Network
1017:Principles of Animal Locomotion
550:and purple snails in the genus
444:Chamisso & Eysenhardt, 1821
372:Chamisso & Eysenhardt, 1821
340:Chamisso & Eysenhardt, 1821
1498:Cnidarians of the Indian Ocean
1019:. Princeton University Press.
922:Nudibranchs of Southern Africa
1:
861:Biodiversity Heritage Library
1154:National Geographic Society
1088:A. Brinckmann-Voss (1970).
1524:
1488:Monotypic cnidarian genera
719:alternation of generations
636:
907:Harrington Wells (1937).
874:Schuchert P, ed. (2013).
544:(sea slugs) in the genus
428:Peron & Lesueur, 1807
192:
185:
162:
155:
50:Scientific classification
48:
39:
30:
23:
1096:. pp. 1–96, 11 pls.
633:Distribution and habitat
533:. Specialized predatory
324:Quoy & Gaimard, 1824
920:Gosliner, T.M. (1987).
884:World Hydrozoa database
853:Lamarck, J. B. (1801).
678:, on the west coast of
639:Ocean surface ecosystem
433:Velella septentrionalis
1141:Animal Diversity Web:
1107:Totton, A. K. (1954).
789:
701:
658:on the water surface.
629:
618:
1013:McNeill Alexander, R.
775:
688:
669:other than its sail,
624:
613:
567:Like other Cnidaria,
531:Portuguese man o' war
1181:. November 27, 2006.
1043:The Irish Naturalist
417:Velella sandwichiana
353:Velella meridionalis
16:Species of cnidarian
1187:Plankton Chronicles
787:Cambria, California
560:by the thousand on
449:Velella tentaculata
401:Velella pyramidalis
233:Armenista sigmoides
1094:Stazione Zoologica
834:Glaucus atlanticus
790:
702:
630:
619:
504:by-the-wind sailor
409:Velella radackiana
393:Velella patellaris
321:Velella emarginata
281:Velella antarctica
241:Holothuria spirans
1470:
1469:
1429:Open Tree of Life
1200:Taxon identifiers
1161:Jellieszone.com:
1156:. April 20, 2015.
1113:Discovery Reports
880:(Linnaeus, 1758)"
469:
468:
461:
460:Eschscholtz, 1829
453:
445:
437:
436:Eschscholtz, 1829
429:
425:Velella scaphidia
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397:
389:
381:
377:Velella oxyothone
373:
365:
357:
349:
341:
333:
332:Eschscholtz, 1829
325:
317:
309:
308:Eschscholtz, 1829
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297:Velella australis
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292:Eschscholtz, 1829
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284:Eschscholtz, 1829
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276:Eschscholtz, 1829
269:
268:Eschscholtz, 1829
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215:Eschscholtz, 1829
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137:
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1382:NBNSYS0000178601
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782:Palmaria palmata
764:hydroid colony.
743:, single-celled
459:
451:
443:
441:Velella sinistra
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395:
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385:Velella pacifica
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35:
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1403:Observation.org
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1336:
1328:
1323:
1315:
1310:
1302:
1297:
1289:
1284:
1276:
1271:
1265:Velella_velella
1263:
1258:
1252:Velella_velella
1250:
1245:
1238:Velella velella
1236:
1235:
1230:
1221:
1220:
1215:
1208:Velella velella
1202:
1173:
1148:
1137:
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961:
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939:
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919:
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892:
890:
878:Velella velella
873:
872:
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851:
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827:Porpita porpita
822:
785:in a tidepool,
777:Velella velella
770:
733:budding process
715:Velella velella
707:
644:Velella velella
641:
635:
569:Velella velella
491:Velella velella
465:
464:
457:Velella tropica
369:Velella oblonga
345:Velella limbosa
305:Velella caurina
273:Rataria mitrata
265:Rataria cordata
249:Medusa pocillum
196:
181:
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166:Velella velella
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148:V. velella
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52:
42:Velella velella
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1135:External links
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1072:. 4 July 2022.
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361:Velella mutica
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329:Velella indica
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318:
313:Velella cyanea
310:
302:
294:
289:Velella aurora
286:
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262:
260:Linnaeus, 1758
257:Medusa velella
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244:Forsskål, 1775
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40:Close-up of a
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806:Siphonophorae
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783:
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745:endosymbiotic
742:
741:zooxanthellae
738:
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700:, California.
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664:
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587:(also called
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420:de Haan, 1827
418:
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412:de Haan, 1827
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388:de Haan, 1827
386:
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364:Lamarck, 1801
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348:Lamarck, 1816
346:
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300:de Haan, 1827
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252:Montagu, 1815
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236:Haeckel, 1888
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223:Haeckel, 1888
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207:Haeckel, 1888
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157:Binomial name
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996:. Retrieved
994:. 2021-05-09
991:
982:
971:. Retrieved
969:. 2024-04-22
966:
957:
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936:
921:
916:
908:
903:
891:. Retrieved
883:
877:
869:
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814:Chondrophora
810:Chondrophora
801:
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698:Marin County
689:
682:in England.
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575:, generally
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527:siphonophore
520:
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514:, or simply
511:
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490:
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478:monospecific
472:
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404:Cranch, 1818
400:
396:Brandt, 1835
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380:Brandt, 1835
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356:Fewkes, 1889
352:
344:
337:Velella lata
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41:
24:
18:
1442:SeaLifeBase
1338:iNaturalist
1232:Wikispecies
768:Systematics
694:Rodeo Beach
597:V. velella'
589:nematocysts
542:nudibranchs
521:This small
512:little sail
508:purple sail
1483:Porpitidae
1477:Categories
1119:: 1–162 .
998:2023-05-21
973:2024-04-23
924:page 127,
841:References
723:gonozooids
709:Like many
705:Life cycle
671:V. velella
667:locomotion
656:V. velella
637:See also:
605:V. velella
601:V. velella
585:cnidocysts
486:Porpitidae
228:(Species)
117:Porpitidae
1050:(3): 40.
614:Stranded
581:tentacles
535:gastropod
523:cnidarian
480:genus of
204:Armenista
142:Species:
73:Kingdom:
67:Eukaryota
1356:10942759
1304:46550209
1223:Q1366657
1217:Wikidata
1179:BBC News
1125:14100651
1056:25525026
1015:(2002).
967:BBC News
893:23 April
820:See also
711:Hydrozoa
680:Cornwall
628:close-up
577:plankton
553:Janthina
538:molluscs
500:sea raft
482:hydrozoa
199:(Genus)
187:Synonyms
174:Linnaeus
113:Family:
97:Hydrozoa
87:Cnidaria
83:Phylum:
77:Animalia
63:Domain:
1330:2265793
1163:Velella
1143:Velella
802:Porpita
798:Velella
762:Velella
758:conaria
753:Velella
749:Velella
737:medusae
730:asexual
690:Velella
663:Velella
652:neuston
626:Velella
616:Velella
591:). The
562:beaches
547:Glaucus
516:Velella
484:in the
473:Velella
220:Velaria
212:Rataria
134:Lamarck
128:Velella
123:Genus:
103:Order:
93:Class:
44:colony
25:Velella
1460:117832
1434:707202
1421:117832
1395:264060
1278:124753
1123:
1054:
1023:
948:
928:
794:genera
779:&
648:polyps
593:toxins
529:, the
136:, 1801
1455:WoRMS
1447:44629
1408:27080
1369:51267
1351:IRMNG
1343:59698
1317:37832
1312:EUNIS
1291:7FL3G
1052:JSTOR
676:Hayle
476:is a
1416:OBIS
1390:NCBI
1364:ITIS
1325:GBIF
1273:BOLD
1121:OCLC
1021:ISBN
946:ISBN
926:ISBN
895:2013
800:and
573:prey
494:, a
195:List
178:1758
1377:NBN
1299:EoL
1286:CoL
1260:AFD
1247:ADW
992:NPR
1479::
1457::
1444::
1431::
1418::
1405::
1392::
1379::
1366::
1353::
1340::
1327::
1314::
1301::
1288::
1275::
1262::
1249::
1234::
1219::
1177:.
1152:.
1117:27
1115:.
1111:.
1078:^
1048:30
1046:.
990:.
965:.
886:.
882:.
713:,
696:,
564:.
556:.
518:.
510:,
506:,
502:,
176:,
1127:.
1058:.
1029:.
1001:.
976:.
952:.
897:.
876:"
863:.
180:)
172:(
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