504:
495:
754:
554:—a practice that has given rise to the name "peanut worm". The introvert is pulled inside the trunk by two pairs of retractor muscles that extend as narrow ribbons from the trunk wall to attachment points in the introvert. It can be protruded from the trunk by contracting the muscles of the trunk wall, thus forcing the fluid in the body cavity forwards. The introvert can vary in size from half the length of the trunk to several times its length, but whatever their comparative sizes, it is fully retractable.
1105:
124:
1117:
958:
102:
790:
933:
those that burrow through the sand, the tentacles are replaced by fluted folds which scoop up sediment and food particles. Most of this material is swallowed but larger particles are discarded. Species dwelling in crevices are able to withdraw their introverts, blocking the crevice entrance with their thickened trunks and presumably ingesting any food they have snared at the same time. One species,
741:
crevice-dwelling sipunculans, respiration is mainly through the tentacular system, with oxygen diffusing into the trunk coelom from the tentacular coelom. However, in other species the skin is thin and respiration is mainly through the cuticle of the trunk, where oxygen uptake is assisted by the presence of dermal coelomic canals just beneath the
737:, which have only a single nephridium. A ciliated funnel, or nephrostome, opens into the coelomic cavity at the anterior end, close to the nephridiopore. The metanephridia have an osmoregulation function but it is unclear whether the mechanism is via filtration or secretion. They also serve as gamete storage and maintenance organs.
312:
section, called the "introvert", which can be retracted into the trunk. The mouth is at the tip of the introvert and is surrounded in most groups by a ring of short tentacles. With no hard parts, the body is flexible and mobile. Although found in a range of habitats throughout the world's oceans, the
623:
family possess epidermal structures, known as anal and caudal shields. These are patches of thickened, hard plates, and are used for boring into rock; the anal shield is near the anteriorly-located anus on the trunk, just below the introvert of the animal, while the caudal shield is at the posterior
518:
Sipunculans are worms ranging from 2 to 720 mm (0.1 to 28.3 in) in length, with most species being under 10 cm (4 in). The sipunculan body is divided into an unsegmented, bulbous trunk and a narrower, anterior section, called the "introvert". Sipunculans have a body wall somewhat
932:
Most sipunculans are deposit feeders employing a number of different methods to obtain their foods. Those living in burrows extend their tentacles over the surface of the sediment. Food particles get trapped in mucous secretions and the beating of cilia transport the particles to the mouth. Among
761:
The nervous system consists of dorsal cerebral ganglion, brain above the oesophagus and a nerve ring around the oesophagus, which links the brain with the single ventral nerve cord that runs the length of the body. Lateral nerves lead off this to innervate the muscles of the body wall.
740:
The tentacular coelom connects the tentacles at the tip of the introvert to a ring canal at their base, from which a contractile vessel runs along beside the esophagus and ends blindly posteriorly. Some evidence points towards the involvement of these structures in ultrafiltration. In
316:
Most sipunculans are deposit feeders, extending the introvert to gather food particles and draw them into the mouth, and retracting the introvert when feeding conditions are unsuitable or danger threatens. With a few exceptions, reproduction is sexual and involves a
668:
of sipunculans starts with the esophagus, located between the introvert retractor muscles. In the trunk the intestine runs posteriorly, forms a loop and turns anteriorly again. The downward and upward sections of the gut are coiled around each other, forming a
592:. The tentacles are hollow and are extended via hydrostatic pressure in a similar manner as the introvert, but have a different mechanism from that of the rest of the introvert, being connected, via a system of ducts, to one or two contractile sacs next to the
685:, taking place in the lumen of the intestine. A rectal caecum, present in most species, is a blind ending sac at the transition between intestine and rectum with unknown function. The anus is often not visible when the introvert is retracted into the trunk.
809:, but the majority of species occur in shallow water, where they are relatively common. They inhabit a range of habitats including burrowing in sand, mud, clay and gravel, hiding under stones, in rock crevices, in hollow coral heads, in wood, in empty
901:
are produced in the coelomic lining, where they are released into the coelom to mature. These gametes are then picked up by the metanephridia system and released into the aquatic environment, where fertilisation takes place. In at least one species,
576:, also located at the tip of the introvert. The tentacles each have a deep groove along which food is moved to the mouth by cilia. They are used to gather organic detritus from the water or substrate, and probably also function as
1349:
Struck, T. H.; Paul, C.; Hill, N.; Hartmann, S.; Hösel, C.; Kube, M.; Lieb, B.; Meyer, A.; Tiedemann, R.; Purschke, G. N.; Bleidorn, C. (3 March 2011). "Phylogenomic analyses unravel annelid evolution".
915:
larva, which metamorphoses into the adult after anything from a day to a month, depending on species. In a few species, the trochophore does not develop directly into the adult, but into an intermediate
781:
annelids. In addition, all sipunculans have numerous sensory nerve endings on the body wall, especially at the forward end of the introvert which is used for exploring the surrounding environment.
840:. These worms may stay submerged in the sea bed for between 10 and 18 hours a day. They are sensitive to low salinities, and thus not commonly found near estuaries. They can also be abundant in
1317:
313:
majority of species live in shallow water habitats, burrowing under the surface of sandy and muddy substrates. Others live under stones, in rock crevices or in other concealed locations.
1265:
Précis des découvertes et travaux somiologiques de m.r C. S. Rafinesque-Schmaltz entre 1800 et 1814 ou Choix raisonné de ses principales découvertes en zoologie et en botanique
481:). It has also been shown that a rudimentary neural segmentation similar to that of annelids occurs in the early larval stage, even if these traits are absent in the adults.
430:), and in time, the term came to be used for the whole class. This is a relatively understudied group, and it is estimated there may be around 162 species worldwide.
1116:
882:
308:
Sipunculans vary in size but most species are under 10 cm (4 in) in length. The body is divided into an unsegmented, bulbous trunk and a narrower,
110:
2191:
469:
and several other phyla. Phylogenetic analyses based on 79 ribosomal proteins indicated a position of
Sipuncula within Annelida. Subsequent analysis of the
2500:
2158:
976:
970:
1149:"A close phylogenetic relationship between Sipuncula and Annelida evidenced from the complete mitochondrial genome sequence of Phascolosoma esculenta"
1075:. It is a basic food for local fisherman and is sometimes seen in city restaurants as an appetizer. This style of food preparation is locally called
1806:
1569:
2372:
1324:
648:
it is composed of separate plates. When the introvert is retracted in these animals, the anal shield blocks the entrance to its burrow. At the
1098:. The relatively high market price of the worms have made them a significant source of income for the local population of fishermen families.
2398:
1671:
Pilger, J.F.; Rice, M.E. (1987). "Ultrastructural evidence for the contractile vessel of sipunculans as a possible ultrafiltration site".
852:
Both asexual and sexual reproduction can be found in sipunculans, although asexual reproduction is uncommon and has only been observed in
632:
the anal shield is restricted to the dorsal side, causing the introvert to emerge at an angle, whereas it surrounds the anterior trunk in
2233:
2495:
1198:
2346:
649:
309:
2385:
2011:
991:, and demonstrate that sipunculans have changed little (morphologically) since the early Cambrian, about 520 million years ago.
1871:
Pechenik, J.A.; Rice, M.E. (1990). "Influence of delayed metamorphosis on postsettlement survival and growth in the sipunculan
604:, either arranged in rings or scattered. They may be involved in scraping algae off rock, or alternatively provide anchorage.
1768:
1701:
1624:
1594:
1553:
1513:
721:, large multinuclear cells, ciliated urn-shaped cells and immature cells. The ciliated urn cells may also be attached to the
2390:
1071:. The muscle is first prepared by soaking it in spiced vinegar and then served with other ingredients as a dish similar to
968:
Because of their soft-bodied structure, fossils of sipunculans are extremely rare, and are only known from a few genera.
1903:
547:
to extend or contract the animal. When threatened, Sipunculid worms can contract their body into a shape resembling a
2457:
2140:
1291:
1241:
332:
1104:
2403:
2166:
2049:
Muir, L. A.; Botting, J. P. (2007). "A Lower
Carboniferous sipunculan from the Granton Shrimp Bed, Edinburgh".
777:, and the nuchal organ, located posterior to the brain. Similar light-sensing tubes have been reported in the
423:
170:
844:, and in Hawaii, up to seven hundred individuals have been found per square metre in burrows in the rock.
2320:
2307:
908:, swarming behaviour occurs with adults creating compact masses among rocks immediately before spawning.
2012:"A new Burgess Shale-type assemblage from the "thin" Stephen Formation of the southern Canadian Rockies"
1813:
924:
occurs only in the presence of suitable habitat conditions, and is triggered by the presence of adults.
2490:
725:
and assist in waste filtering from the coelomic fluid. Nitrogenous waste is excreted through a pair of
123:
2413:
2325:
1760:
1754:
1229:
1095:
2462:
1403:"Spiralian Phylogenomics Supports the Resurrection of Bryozoa Comprising Ectoprocta and Entoprocta"
1283:
369:
584:
the tentacles form an elaborate crown-like structure, the members of this group being specialized
805:; they are found throughout the world's oceans including polar waters, equatorial waters and the
682:
398:
394:
2439:
2247:
869:
833:
organisms on man-made structures. Some bore into solid rocks to make a shelter for themselves.
384:
379:
292:
1691:
1614:
656:; this may help with anchoring the animal in its burrow or may be used in the boring process.
2434:
2227:
1269:
1032:
935:
2449:
2426:
1584:
2485:
2333:
2294:
2108:
2058:
2023:
1359:
1027:
Some scientists once hypothesized a close relationship between sipunculans and the extinct
854:
544:
2377:
753:
8:
2285:
1983:
Eibye-Jacobsen, D.; Vinther, J. (February 2012). "Reconstructing the ancestral annelid".
1206:
860:
601:
2215:
2112:
2062:
2027:
1640:
Schulze, A.; et al. (March 2005). "Reconstructing the phylogeny of the
Sipuncula".
1363:
596:. Hooks are often present near the mouth on the introvert. These are proteinaceous, non-
2132:
2074:
1960:
1935:
1888:
1653:
1563:
1468:
1443:
1383:
1175:
1148:
1048:
1009:
984:
945:
818:
773:
are located near its anterior margin; the non-ciliated cerebral organ, which possesses
343:
118:
321:
larval stage. Sipunculid worms are used as food in some countries in south-east Asia.
2421:
2124:
2078:
1996:
1965:
1764:
1734:
1697:
1620:
1590:
1549:
1509:
1473:
1424:
1375:
1263:
1180:
904:
865:
569:
543:(body cavity) that is filled with fluid on which the body wall musculature acts as a
437:
placement of this group in the past has proved troublesome. Originally classified as
217:
197:
1657:
1315:
1039:
with which they share a helical gut; but this hypothesis has since been discounted.
2136:
2116:
2066:
2031:
1992:
1955:
1947:
1884:
1851:
1730:
1645:
1463:
1455:
1414:
1387:
1367:
1170:
1160:
794:
620:
411:
206:
187:
2299:
363:
2312:
2091:
999:
887:
665:
183:
179:
1934:
Huang, D. -Y.; Chen, J. -Y.; Vannier, J.; Saiz
Salinas, J. I. (22 August 2004).
503:
2010:
Caron, J. -B.; Gaines, R. R.; Mangano, M. G.; Streng, M.; Daley, A. C. (2010).
1122:
This sipunculid worm dish is made by adding vinegar and local spices. Taken in
994:
An unnamed sipunculid worm from the
Cambrian period has been discovered in the
841:
778:
774:
458:
358:
245:
1649:
710:
705:, and the separate tentacular system, the two being separated by an elaborate
494:
2479:
2270:
1165:
1063:. A sipunculid worm dish is also considered a delicacy in the islands of the
1020:
of burrows that may have been formed by sipunculans have been found from the
995:
921:
890:; eggs produced in the absence of sperm developed through the normal stages.
770:
585:
470:
450:
445:
and other annelid characters, the phylum
Sipuncula was later allied with the
434:
405:
59:
1442:
Wanninger, Andreas; Kristof, Alen; Brinkmann, Nora (January–February 2009).
1419:
1402:
2128:
1969:
1951:
1856:
1839:
1477:
1428:
1379:
1184:
1017:
806:
702:
670:
573:
558:
478:
427:
251:
239:
227:
305:, but was demoted to a class of Annelida, based on recent molecular work.
2359:
2279:
2093:
1717:
Purschke, Günter (2011). "Sipunculid-like ocellar tubes in a polychaete,
1459:
1068:
988:
957:
912:
718:
697:
system. Fluid transport and gas exchange are instead accomplished by the
589:
581:
540:
473:'s DNA has confirmed their close relationship to the Annelida (including
257:
233:
34:
2120:
2070:
1371:
769:
associated with the brain. Two organs, likely functioning as a unit for
572:, the tentacles are arranged in an arc above the mouth, surrounding the
557:
The mouth is located at the anterior end of the animal; in the subclass
1036:
1004:
837:
726:
722:
714:
593:
352:
347:
79:
44:
911:
Although some species hatch directly into the adult form, many have a
101:
2364:
2035:
1689:
1612:
1094:
as well, where they are caught on the coasts of Minh Chao island, in
1021:
940:
894:
742:
524:
135:
84:
2241:
2226:
920:
stage, that possesses a greatly enlarged metatroch (ciliated band).
789:
2264:
2220:
1508:. Philadelphia, PA: Holt-Saunders International. pp. 863–870.
1060:
1013:
981:
822:
810:
652:
end of the trunk, a hardened caudal shield is sometimes present in
565:
466:
446:
318:
74:
69:
54:
49:
39:
2351:
2192:"Women earn a living digging for peanut worms in northern Vietnam"
1090:
The worms, especially in dried form, are considered a delicacy in
457:
characters. These phyla have been included in a larger group, the
1316:
Pancucci-Papadopoulou, M.A.; Murina, G.V.V.; Zenetos, A. (2014).
1091:
1080:
1076:
1072:
1064:
1028:
877:
830:
802:
532:
520:
474:
462:
442:
438:
298:
288:
155:
89:
64:
1544:
Ruppert, Edward E.; Fox, Richard, S.; Barnes, Robert D. (2004).
1268:. Royale typographie militaire, aux dépens de l'auteur. p.
943:, gaining entrance in some way to the interior of the sea mouse
535:, an outer layer of circular and an inner layer of longitudinal
898:
829:
and in the empty tubes of other organisms, and some live among
826:
766:
706:
698:
674:
597:
562:
548:
536:
528:
302:
145:
2092:
Moysiuk,Joseph; Smith, Martin R.; Caron, Jean-Bernard (2017).
1792:) in relation with geo-environmental characteristics." (2007).
1261:
2338:
1788:
Nguyen, Thi Thu Ha, et al. "The distribution of peanut-worm (
1721:(Annelida, Fauveliopsidae): implications for eye evolution".
1084:
1056:
1052:
814:
694:
454:
382:
1933:
1804:
1985:
Journal of
Zoological Systematics and Evolutionary Research
1123:
681:, located in the anterior third of the trunk. Digestion is
678:
577:
551:
1441:
295:
2009:
1870:
1639:
1586:
The
Sipuncula: Their Systematics, Biology, and Evolution
512:
A sipunculan with introvert everted (left) and retracted
1940:
Proceedings of the Royal
Society B: Biological Sciences
1936:"Early Cambrian sipunculan worms from southwest China"
1670:
1348:
426:
used the word "Sipuncula" to describe the family (now
1982:
1582:
1323:. National Centre for Marine Research. Archived from
836:
They are common below the surface of the sediment on
2156:
1840:"Larval development and metamorphosis in Sipuncula"
588:, unlike the other groups of sipunculans which are
1976:
1227:
765:In some species, there are simple light-sensitive
1784:
1782:
1780:
1503:
2477:
1716:
1693:Polychaetes & Allies: The Southern Synthesis
1616:Polychaetes & Allies: The Southern Synthesis
1543:
987:in China. These fossils appear to belong to the
636:with the introvert emerging from its center. In
561:, the mouth is surrounded by a mass of 18 to 24
1318:"The phylum Sipuncula in the Mediterranean Sea"
864:. These reproduce asexually through transverse
523:(though unsegmented) in that it consists of an
1777:
1690:Australian Biological Resources Study (2000).
1613:Australian Biological Resources Study (2000).
640:the shield is a hardened, horny structure; in
1904:"Factors influencing larval metamorphosis in
1146:
964:, a sipunculan from the Silurian of Illinois.
441:, despite the complete lack of segmentation,
1929:
1927:
1925:
1568:: CS1 maint: multiple names: authors list (
1147:Shen, X.; Ma, X.; Ren, J.; Zhao, F. (2009).
2501:Taxa named by Constantine Samuel Rafinesque
2159:"Peanut worm jelly: It's what's for dinner"
2048:
1633:
1394:
784:
417:
409:
373:
361:
350:
337:
1901:
1837:
1539:
1537:
1535:
1533:
1531:
1529:
1527:
1525:
1311:
1309:
1142:
1140:
1012:, near Edinburgh, Scotland, dating to the
673:. At the termination of the gut coil, the
100:
2157:Dorman, Jeremy Alban (16 December 2009).
2003:
1959:
1922:
1855:
1467:
1418:
1342:
1255:
1205:. Oxford University Press. Archived from
1174:
1164:
701:, which contains the respiratory pigment
2042:
1748:
1746:
1744:
1608:
1606:
1400:
956:
949:and sucking out its liquefied contents.
788:
752:
2221:Sipuncula in "Tree of Life web project"
2094:"Hyoliths are Palaeozoic lophophorates"
1805:Rice, Mary E.; Pilger, John F. (1988).
1800:
1798:
1589:. Cornell University Press. p. 5.
1522:
1306:
1262:Rafinesque, Constantine Samuel (1814).
1137:
713:contains five types of coelomic cells:
422:in 1767. In 1814, the French zoologist
2478:
2216:Introduction to the Sipuncula, by UCMP
2186:
2184:
1664:
1576:
1548:. Cengage Learning. pp. 495–501.
2246:
2245:
1752:
1741:
1603:
1499:
1497:
1495:
1493:
1491:
1489:
1487:
1448:Communicative and Integrative Biology
729:opening close to the anus, except in
16:Phylum of invertebrates, peanut worms
2414:4554bec7-b7cd-4189-9c31-25fee2056b1a
2146:from the original on 9 October 2022.
1795:
1756:Encyclopedia of Marine Invertebrates
1683:
801:All sipunculid worms are marine and
2181:
886:, has been recorded as reproducing
693:Sipunculans do not have a vascular
659:
13:
2165:. Never yet melted. Archived from
1889:10.1111/j.1744-7410.2001.tb00025.x
1484:
1401:Hausdorf, B.; et al. (2007).
301:. Sipuncula was once considered a
287:) is a class containing about 162
14:
2512:
2496:Extant Cambrian first appearances
2209:
1696:. Csiro Publishing. p. 383.
1619:. Csiro Publishing. p. 378.
1546:Invertebrate Zoology, 7th edition
1110:A plate of Sipunculid worm jelly.
748:
1997:10.1111/j.1439-0469.2011.00651.x
1735:10.1111/j.1744-7410.2011.00226.x
1292:World Register of Marine Species
1242:World Register of Marine Species
1115:
1103:
952:
502:
493:
333:List of bilaterial animal orders
122:
32:
2150:
2085:
1895:
1864:
1831:
1710:
1407:Molecular Biology and Evolution
872:of vital body components, with
847:
1583:Cutler, Edward Bayler (1994).
1444:"Sipunculans and segmentation"
1435:
1276:
1221:
1191:
688:
539:. The body wall surrounds the
519:similar to that of most other
1:
2194:. Tuoi Tre News. 16 June 2018
1759:. TFH Publications. pp.
1232:Sipunculus (Sipunculus) nudus
1131:
1083:, and is also used for fish,
1051:) is a delicacy in southeast
1008:has been identified from the
880:. One species of sipunculan,
813:and inside the bones of dead
424:Constantine Samuel Rafinesque
927:
893:Most sipunculan species are
644:it is a calcareous cone; in
346:variant of the now-obsolete
7:
2051:Scottish Journal of Geology
1228:Saiz-Salinas, José (2009).
757:Nervous system of Sipuncula
326:
10:
2517:
1912:Bulletin of Marine Science
1719:Fauveliopsis cf. adriatica
1504:Barnes, Robert D. (1982).
1203:Oxford Living Dictionaries
1042:
484:
383:
357:, itself a variant of the
330:
2254:
1650:10.1007/s10750-004-4404-3
461:, that also includes the
449:, mostly on the basis of
408:first described the worm
193:
178:
119:Scientific classification
117:
108:
99:
23:
1753:Walls, Jerry G. (1982).
1166:10.1186/1471-2164-10-136
785:Distribution and habitat
677:emerges and ends in the
568:, while in the subclass
2234:Encyclopædia Britannica
1047:Sipunculid worm jelly (
600:specializations of the
404:The Swedish naturalist
213:Order Phascolosomatida
2237:(11th ed.). 1911.
1952:10.1098/rspb.2004.2774
965:
798:
758:
418:
410:
374:
362:
351:
338:
202:Order Aspidosiphonida
2435:Paleobiology Database
2228:"Sipunculoidea"
1420:10.1093/molbev/msm214
960:
936:Thysanocardia procera
883:Themiste lageniformis
792:
775:bipolar sensory cells
756:
1877:Invertebrate Biology
1873:Apionsoma misakianum
1857:10.1093/icb/16.3.563
1723:Invertebrate Biology
1644:. 535/536: 277–296.
1506:Invertebrate Zoology
1460:10.4161/cib.2.1.7505
962:Lecthaylus gregarius
876:also reproducing by
855:Aspidosiphon elegans
817:. Some hide in kelp
545:hydrostatic skeleton
2121:10.1038/nature20804
2113:2017Natur.541..394M
2071:10.1144/sjg43010051
2063:2007ScJG...43...51M
2028:2010Geo....38..811C
1906:Golfingia misakiana
1902:Rice, M.E. (1986).
1838:Rice, M.E. (1976).
1372:10.1038/nature09864
1364:2011Natur.471...95S
1330:on 12 February 2019
1209:on 12 February 2019
888:parthenogenetically
861:Sipunculus robustus
821:, under tangles of
368:("little tube"), a
111:Thysanocardia nigra
2169:on 9 February 2019
1844:American Zoologist
1055:, originally from
1010:Granton Shrimp Bed
966:
946:Aphrodita aculeata
799:
759:
2491:Spiralian classes
2473:
2472:
2422:Open Tree of Life
2248:Taxon identifiers
2107:(7637): 394–397.
1770:978-0-86622-141-2
1703:978-0-643-06571-0
1626:978-0-643-06571-0
1596:978-0-8014-2843-2
1555:978-81-315-0104-7
1515:978-0-03-056747-6
1413:(12): 2723–2729.
939:is thought to be
905:Themiste pyroides
570:Phascolosomatidea
269:
268:
218:Phascolosomatidae
198:Phascolosomatidea
174:
2508:
2466:
2465:
2453:
2452:
2443:
2442:
2430:
2429:
2417:
2416:
2407:
2406:
2394:
2393:
2381:
2380:
2368:
2367:
2355:
2354:
2342:
2341:
2329:
2328:
2316:
2315:
2303:
2302:
2290:
2289:
2288:
2275:
2274:
2273:
2243:
2242:
2238:
2230:
2204:
2203:
2201:
2199:
2188:
2179:
2178:
2176:
2174:
2154:
2148:
2147:
2145:
2098:
2089:
2083:
2082:
2046:
2040:
2039:
2036:10.1130/G31080.1
2007:
2001:
2000:
1980:
1974:
1973:
1963:
1946:(1549): 1671–6.
1931:
1920:
1919:
1899:
1893:
1892:
1868:
1862:
1861:
1859:
1835:
1829:
1828:
1826:
1824:
1818:
1812:. Archived from
1811:
1802:
1793:
1790:Sipunculus nudus
1786:
1775:
1774:
1750:
1739:
1738:
1714:
1708:
1707:
1687:
1681:
1680:
1673:American Zoology
1668:
1662:
1661:
1637:
1631:
1630:
1610:
1601:
1600:
1580:
1574:
1573:
1567:
1559:
1541:
1520:
1519:
1501:
1482:
1481:
1471:
1439:
1433:
1432:
1422:
1398:
1392:
1391:
1346:
1340:
1339:
1337:
1335:
1329:
1322:
1313:
1304:
1303:
1301:
1299:
1280:
1274:
1273:
1259:
1253:
1252:
1250:
1248:
1225:
1219:
1218:
1216:
1214:
1195:
1189:
1188:
1178:
1168:
1144:
1119:
1107:
1096:Van Don District
1087:and vegetables.
1035:shells from the
985:Chengjiang biota
977:Cambrosipunculus
971:Archaeogolfingia
795:Sipunculus nudus
660:Digestive system
624:of the body. In
621:Aspidosiphonidae
580:. In the family
506:
497:
421:
415:
412:Sipunculus nudus
388:
387:
377:
367:
356:
341:
281:sipunculid worms
207:Aspidosiphonidae
169:
127:
126:
104:
94:
31:
27:Temporal range:
21:
20:
2516:
2515:
2511:
2510:
2509:
2507:
2506:
2505:
2476:
2475:
2474:
2469:
2461:
2456:
2448:
2446:
2438:
2433:
2425:
2420:
2412:
2410:
2402:
2397:
2389:
2384:
2376:
2371:
2363:
2358:
2350:
2345:
2337:
2332:
2324:
2319:
2311:
2306:
2298:
2293:
2284:
2283:
2278:
2269:
2268:
2263:
2250:
2225:
2212:
2207:
2197:
2195:
2190:
2189:
2182:
2172:
2170:
2155:
2151:
2143:
2096:
2090:
2086:
2047:
2043:
2008:
2004:
1981:
1977:
1932:
1923:
1900:
1896:
1869:
1865:
1836:
1832:
1822:
1820:
1816:
1809:
1803:
1796:
1787:
1778:
1771:
1751:
1742:
1715:
1711:
1704:
1688:
1684:
1669:
1665:
1638:
1634:
1627:
1611:
1604:
1597:
1581:
1577:
1561:
1560:
1556:
1542:
1523:
1516:
1502:
1485:
1440:
1436:
1399:
1395:
1358:(7336): 95–98.
1347:
1343:
1333:
1331:
1327:
1320:
1314:
1307:
1297:
1295:
1282:
1281:
1277:
1260:
1256:
1246:
1244:
1234:Linnaeus, 1766"
1226:
1222:
1212:
1210:
1197:
1196:
1192:
1145:
1138:
1134:
1127:
1120:
1111:
1108:
1045:
1000:Alberta, Canada
955:
930:
850:
787:
751:
691:
666:digestive tract
662:
590:deposit feeders
516:
515:
514:
513:
509:
508:
507:
499:
498:
487:
419:Systema Naturae
335:
329:
168:
121:
95:
93:
92:
87:
82:
77:
72:
67:
62:
57:
52:
47:
42:
37:
30:Cambrian–Recent
29:
28:
25:
17:
12:
11:
5:
2514:
2504:
2503:
2498:
2493:
2488:
2471:
2470:
2468:
2467:
2454:
2444:
2431:
2418:
2408:
2395:
2382:
2369:
2356:
2343:
2330:
2317:
2304:
2291:
2276:
2260:
2258:
2252:
2251:
2240:
2239:
2223:
2218:
2211:
2210:External links
2208:
2206:
2205:
2180:
2149:
2084:
2041:
2022:(9): 811–814.
2002:
1975:
1921:
1894:
1863:
1850:(3): 563–571.
1830:
1794:
1776:
1769:
1740:
1729:(2): 115–128.
1709:
1702:
1682:
1663:
1632:
1625:
1602:
1595:
1575:
1554:
1521:
1514:
1483:
1434:
1393:
1341:
1305:
1275:
1254:
1220:
1190:
1135:
1133:
1130:
1129:
1128:
1126:, Philippines.
1121:
1114:
1112:
1109:
1102:
1044:
1041:
980:appear in the
954:
951:
929:
926:
868:, followed by
849:
846:
842:coralline rock
786:
783:
771:chemoreception
750:
749:Nervous system
747:
711:coelomic fluid
690:
687:
683:extra-cellular
661:
658:
642:Lithacrosiphon
630:Lithacrosiphon
613:Lithacrosiphon
607:Three genera (
586:filter feeders
531:overlain by a
511:
510:
501:
500:
492:
491:
490:
489:
488:
486:
483:
459:Lophotrochozoa
328:
325:
279:(common names
267:
266:
265:
264:
263:
262:
261:
260:
254:
248:
246:Phascolionidae
242:
224:
223:
222:
221:
220:
211:
210:
209:
191:
190:
176:
175:
163:
159:
158:
153:
149:
148:
143:
139:
138:
133:
129:
128:
115:
114:
106:
105:
97:
96:
88:
83:
78:
73:
68:
63:
58:
53:
48:
43:
38:
33:
26:
15:
9:
6:
4:
3:
2:
2513:
2502:
2499:
2497:
2494:
2492:
2489:
2487:
2484:
2483:
2481:
2464:
2459:
2455:
2451:
2445:
2441:
2436:
2432:
2428:
2423:
2419:
2415:
2409:
2405:
2400:
2396:
2392:
2387:
2383:
2379:
2374:
2370:
2366:
2361:
2357:
2353:
2348:
2344:
2340:
2335:
2331:
2327:
2322:
2318:
2314:
2309:
2305:
2301:
2296:
2292:
2287:
2281:
2277:
2272:
2266:
2262:
2261:
2259:
2257:
2253:
2249:
2244:
2236:
2235:
2229:
2224:
2222:
2219:
2217:
2214:
2213:
2193:
2187:
2185:
2168:
2164:
2163:The Telegraph
2160:
2153:
2142:
2138:
2134:
2130:
2126:
2122:
2118:
2114:
2110:
2106:
2102:
2095:
2088:
2080:
2076:
2072:
2068:
2064:
2060:
2056:
2052:
2045:
2037:
2033:
2029:
2025:
2021:
2017:
2013:
2006:
1998:
1994:
1990:
1986:
1979:
1971:
1967:
1962:
1957:
1953:
1949:
1945:
1941:
1937:
1930:
1928:
1926:
1918:(2): 362–375.
1917:
1913:
1909:
1907:
1898:
1890:
1886:
1882:
1878:
1874:
1867:
1858:
1853:
1849:
1845:
1841:
1834:
1819:on 5 May 2017
1815:
1808:
1801:
1799:
1791:
1785:
1783:
1781:
1772:
1766:
1762:
1758:
1757:
1749:
1747:
1745:
1736:
1732:
1728:
1724:
1720:
1713:
1705:
1699:
1695:
1694:
1686:
1678:
1674:
1667:
1659:
1655:
1651:
1647:
1643:
1642:Hydrobiologia
1636:
1628:
1622:
1618:
1617:
1609:
1607:
1598:
1592:
1588:
1587:
1579:
1571:
1565:
1557:
1551:
1547:
1540:
1538:
1536:
1534:
1532:
1530:
1528:
1526:
1517:
1511:
1507:
1500:
1498:
1496:
1494:
1492:
1490:
1488:
1479:
1475:
1470:
1465:
1461:
1457:
1453:
1449:
1445:
1438:
1430:
1426:
1421:
1416:
1412:
1408:
1404:
1397:
1389:
1385:
1381:
1377:
1373:
1369:
1365:
1361:
1357:
1353:
1345:
1326:
1319:
1312:
1310:
1293:
1289:
1285:
1279:
1271:
1267:
1266:
1258:
1243:
1239:
1235:
1233:
1224:
1208:
1204:
1200:
1194:
1186:
1182:
1177:
1172:
1167:
1162:
1158:
1154:
1150:
1143:
1141:
1136:
1125:
1118:
1113:
1106:
1101:
1100:
1099:
1097:
1093:
1088:
1086:
1082:
1078:
1074:
1070:
1066:
1062:
1058:
1054:
1050:
1040:
1038:
1034:
1030:
1025:
1023:
1019:
1018:Trace fossils
1015:
1011:
1007:
1006:
1001:
997:
996:Burgess Shale
992:
990:
986:
983:
979:
978:
973:
972:
963:
959:
953:Fossil record
950:
948:
947:
942:
938:
937:
925:
923:
922:Metamorphosis
919:
918:pelagosphaera
914:
909:
907:
906:
900:
896:
891:
889:
885:
884:
879:
875:
871:
867:
863:
862:
857:
856:
845:
843:
839:
834:
832:
828:
824:
820:
816:
812:
808:
804:
797:
796:
791:
782:
780:
776:
772:
768:
763:
755:
746:
744:
738:
736:
732:
728:
727:metanephridia
724:
720:
716:
712:
708:
704:
700:
696:
686:
684:
680:
676:
672:
667:
657:
655:
651:
647:
643:
639:
635:
631:
627:
622:
618:
614:
610:
605:
603:
599:
595:
591:
587:
583:
579:
575:
571:
567:
564:
560:
555:
553:
550:
546:
542:
538:
534:
530:
526:
522:
505:
496:
482:
480:
479:pogonophorans
476:
472:
471:mitochondrion
468:
464:
460:
456:
452:
451:developmental
448:
444:
440:
436:
431:
429:
425:
420:
414:
413:
407:
406:Carl Linnaeus
402:
400:
396:
392:
386:
381:
376:
371:
366:
365:
360:
355:
354:
349:
345:
340:
334:
324:
322:
320:
314:
311:
306:
304:
300:
299:annelid worms
297:
294:
290:
286:
282:
278:
274:
259:
255:
253:
249:
247:
243:
241:
237:
236:
235:
231:
230:
229:
225:
219:
215:
214:
212:
208:
204:
203:
201:
200:
199:
195:
194:
192:
189:
185:
181:
177:
172:
167:
164:
161:
160:
157:
154:
151:
150:
147:
144:
141:
140:
137:
134:
131:
130:
125:
120:
116:
113:
112:
107:
103:
98:
91:
86:
81:
76:
71:
66:
61:
56:
51:
46:
41:
36:
22:
19:
2255:
2232:
2196:. Retrieved
2171:. Retrieved
2167:the original
2162:
2152:
2104:
2100:
2087:
2057:(1): 51–56.
2054:
2050:
2044:
2019:
2015:
2005:
1988:
1984:
1978:
1943:
1939:
1915:
1911:
1908:(Sipuncula)"
1905:
1897:
1883:(1): 50–57.
1880:
1876:
1872:
1866:
1847:
1843:
1833:
1821:. Retrieved
1814:the original
1789:
1755:
1726:
1722:
1718:
1712:
1692:
1685:
1676:
1672:
1666:
1641:
1635:
1615:
1585:
1578:
1545:
1505:
1454:(1): 56–59.
1451:
1447:
1437:
1410:
1406:
1396:
1355:
1351:
1344:
1332:. Retrieved
1325:the original
1296:. Retrieved
1287:
1278:
1264:
1257:
1245:. Retrieved
1237:
1231:
1223:
1211:. Retrieved
1207:the original
1202:
1193:
1156:
1153:BMC Genomics
1152:
1089:
1046:
1026:
1003:
993:
975:
969:
967:
961:
944:
934:
931:
917:
910:
903:
892:
881:
873:
870:regeneration
859:
853:
851:
848:Reproduction
835:
807:abyssal zone
800:
793:
779:fauveliopsid
764:
760:
739:
734:
730:
719:granulocytes
703:haemerythrin
692:
671:double helix
663:
654:Aspidosiphon
653:
645:
641:
638:Aspidosiphon
637:
633:
629:
626:Aspidosiphon
625:
616:
612:
609:Aspidosiphon
608:
606:
574:nuchal organ
559:Sipunculidea
556:
517:
467:ribbon worms
435:phylogenetic
432:
428:Sipunculidae
403:
390:
336:
323:
315:
307:
285:peanut worms
284:
280:
276:
272:
270:
252:Sipunculidae
240:Golfingiidae
228:Sipunculidea
165:
109:
18:
2486:Sipunculans
2360:iNaturalist
2280:Wikispecies
1807:"Sipuncula"
1334:10 February
1298:27 February
1284:"Sipuncula"
1247:27 February
1213:10 February
1199:"Sipuncula"
1069:Philippines
989:crown group
941:carnivorous
913:trochophore
874:S. robustus
838:tidal flats
689:Circulation
646:Cloeosiphon
634:Cloeosiphon
617:Cloeosiphon
582:Themistidae
537:musculature
364:siphunculus
293:unsegmented
277:Sipunculida
258:Themistidae
234:Golfingiida
2480:Categories
2198:9 February
2173:9 February
1823:6 February
1132:References
1037:Palaeozoic
1033:operculate
1005:Lecthaylus
735:Onchnesoma
731:Phascolion
723:peritoneum
715:haemocytes
594:oesophagus
370:diminutive
353:Sipunculus
348:genus name
331:See also:
319:planktonic
180:Subclasses
171:Rafinesque
2313:Sipuncula
2300:Sipuncula
2286:Sipuncula
2256:Sipuncula
2079:131119101
1991:: 85–87.
1564:cite book
1022:Paleozoic
928:Behaviour
895:dioecious
825:, inside
819:holdfasts
811:seashells
743:epidermis
650:posterior
619:) in the
602:epidermis
598:chitinous
566:tentacles
525:epidermis
475:echiurans
339:Sipuncula
273:Sipuncula
226:Subclass
196:Subclass
166:Sipuncula
142:Kingdom:
136:Eukaryota
24:Sipuncula
2265:Wikidata
2141:Archived
2129:28077871
1970:15306286
1658:20948259
1478:19513266
1429:17921486
1380:21368831
1185:19327168
1067:region,
1061:Quanzhou
1029:hyoliths
1016:period.
1014:Silurian
982:Cambrian
897:. Their
823:eelgrass
563:ciliated
527:without
521:annelids
463:annelids
447:Mollusca
443:bristles
439:annelids
344:feminine
327:Taxonomy
310:anterior
188:families
156:Annelida
152:Phylum:
146:Animalia
132:Domain:
2271:Q205712
2137:4409157
2109:Bibcode
2059:Bibcode
2024:Bibcode
2016:Geology
1961:1691784
1761:255–262
1679:: 810a.
1469:2649304
1388:4428998
1360:Bibcode
1176:2667193
1159:: 136.
1092:Vietnam
1081:kinilaw
1077:kilawin
1073:ceviche
1065:Visayas
1059:, near
1043:As food
899:gametes
878:budding
866:fission
831:fouling
827:sponges
803:benthic
533:cuticle
485:Anatomy
416:in his
289:species
256:Family
250:Family
244:Family
238:Family
216:Family
205:Family
162:Class:
2450:230457
2447:uBio:
2427:377817
2411:NZOR:
2391:154520
2135:
2127:
2101:Nature
2077:
1968:
1958:
1767:
1700:
1656:
1623:
1593:
1552:
1512:
1476:
1466:
1427:
1386:
1378:
1352:Nature
1294:. 2018
1183:
1173:
1002:, and
815:whales
767:ocelli
709:. The
707:septum
699:coelom
675:rectum
552:kernel
549:peanut
541:coelom
465:, the
455:larval
391:síphōn
303:phylum
296:marine
232:Order
184:orders
173:, 1814
2458:WoRMS
2440:67166
2373:IRMNG
2365:48665
2144:(PDF)
2133:S2CID
2097:(PDF)
2075:S2CID
1817:(PDF)
1810:(PDF)
1654:S2CID
1384:S2CID
1328:(PDF)
1321:(PDF)
1288:WoRMS
1238:WoRMS
1085:conch
1057:Anhai
1053:China
695:blood
578:gills
529:cilia
385:σίφων
380:Greek
378:from
375:sipho
359:Latin
342:is a
2463:1268
2404:6433
2399:NCBI
2386:ITIS
2347:GBIF
2339:8871
2321:BOLD
2200:2019
2175:2019
2125:PMID
1966:PMID
1825:2019
1765:ISBN
1698:ISBN
1621:ISBN
1591:ISBN
1570:link
1550:ISBN
1510:ISBN
1474:PMID
1425:PMID
1376:PMID
1336:2019
1300:2019
1249:2019
1215:2019
1181:PMID
1124:Cebu
974:and
858:and
733:and
679:anus
664:The
628:and
615:and
477:and
453:and
433:The
401:").
399:pipe
395:tube
271:The
186:and
35:PreꞒ
2378:200
2334:EoL
2308:AFD
2295:ADW
2117:doi
2105:541
2067:doi
2032:doi
1993:doi
1956:PMC
1948:doi
1944:271
1885:doi
1881:120
1875:".
1852:doi
1731:doi
1727:130
1646:doi
1464:PMC
1456:doi
1415:doi
1368:doi
1356:471
1171:PMC
1161:doi
1079:or
1049:土笋凍
998:in
393:, "
372:of
291:of
283:or
275:or
2482::
2460::
2437::
2424::
2401::
2388::
2375::
2362::
2352:74
2349::
2336::
2326:15
2323::
2310::
2297::
2282::
2267::
2231:.
2183:^
2161:.
2139:.
2131:.
2123:.
2115:.
2103:.
2099:.
2073:.
2065:.
2055:43
2053:.
2030:.
2020:38
2018:.
2014:.
1989:50
1987:.
1964:.
1954:.
1942:.
1938:.
1924:^
1916:39
1914:.
1910:.
1879:.
1848:16
1846:.
1842:.
1797:^
1779:^
1763:.
1743:^
1725:.
1677:27
1675:.
1652:.
1605:^
1566:}}
1562:{{
1524:^
1486:^
1472:.
1462:.
1450:.
1446:.
1423:.
1411:24
1409:.
1405:.
1382:.
1374:.
1366:.
1354:.
1308:^
1290:.
1286:.
1270:32
1240:.
1236:.
1201:.
1179:.
1169:.
1157:10
1155:.
1151:.
1139:^
1031:,
1024:.
745:.
717:,
611:,
397:,
182:,
85:Pg
2202:.
2177:.
2119::
2111::
2081:.
2069::
2061::
2038:.
2034::
2026::
1999:.
1995::
1972:.
1950::
1891:.
1887::
1860:.
1854::
1827:.
1773:.
1737:.
1733::
1706:.
1660:.
1648::
1629:.
1599:.
1572:)
1558:.
1518:.
1480:.
1458::
1452:2
1431:.
1417::
1390:.
1370::
1362::
1338:.
1302:.
1272:.
1251:.
1230:"
1217:.
1187:.
1163::
389:(
90:N
80:K
75:J
70:T
65:P
60:C
55:D
50:S
45:O
40:Ꞓ
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
