102:
120:
370:, which includes the earthworms as the largest members of the group, mostly live on land, burrowing in damp soil. Smaller freshwater species burrow in mud or live among aquatic vegetation. The marine species are mostly tiny and live in the interstices between sand grains, from the intertidal zone to the deep sea.
283:
or is located just behind them. During copulation, this glandular tissue secretes mucus that keeps the paired individuals together while they exchange sperm. Afterwards it secretes material that forms a cocoon that encircles the animal's body and encloses the eggs and sperm. The animal works this
323:
on the upper side. The clitellum occupies segments 9 to 11 but is only noticeable during breeding periods. The hindermost segments form another, larger, disc-shaped sucker located on the underside of the body. The anus is on the dorsal surface just in front of the posterior sucker. The body wall
318:
Leeches, order
Hirudinida, mostly have flattened bodies, usually tapered at both ends. They have a fixed number of segments, 33, but the segmentation is not visible externally because the cuticle is marked with annulations. Leeches do not bear chaetae. The front few segments or head have been
390:
and sperm into the coat, which is then packed into a cocoon. The zygotes then develop directly in the cocoon without passing through a larval stage (as opposed to other annelids, e.g. Polychaeta.) This mechanism is considered to be apomorphic (a newly derived characteristic rather than an
577:
Tessler, Michael; de Carle, Danielle; Voiklis, Madeleine L.; Gresham, Olivia A.; Neumann, Johannes S.; Cios, Stanisław; Siddall, Mark E. (1 October 2018). "Worms that suck: Phylogenetic analysis of
Hirudinea solidifies the position of Acanthobdellida and necessitates the dissolution of
382:. During copulation, the clitellum produces a mucus that holds worms in place whilst they mate. During reproduction, the clitellum secretes a yolk (albumen) and a proteinaceous sheath which hardens. The worm then creeps out backward from the coat and deposits either fertilized
684:
Struck, Torsten H.; Paul, Christiane; Hill, Natascha; Hartmann, Stefanie; Hösel, Christoph; Kube, Michael; Lieb, Bernhard; Meyer, Achim; Tiedemann, Ralph; Purschke, Günter; Bleidorn, Christoph (2011). "Phylogenomic analyses unravel annelid evolution".
736:
Weigert, Anne; Helm, Conrad; Meyer, Matthias; Nickel, Birgit; Arendt, Detlev; Hausdorf, Bernhard; Santos, Scott R.; Halanych, Kenneth M.; Purschke, Günter; Bleidorn, Christoph; Struck, Torsten H. (2014).
279:(proboscis). The brain is not located in the head but in one of the body segments. The clitellum is formed by a modification of several segments, and either includes the female
604:
552:
788:"Worms that suck: Phylogenetic analysis of Hirudinea solidifies the positionof Acanthobdellida and necessitates the dissolution of Rhynchobdellida"
538:
786:
Tessler, Michael; de Carle, Danielle; Voiklis, Madeleine L.; Gresham, Olivia A.; Neumann, Johannes; Cios, Stanisław; Siddall, Mark E. (2018).
284:
cocoon forward and over its head end, whereupon the ends of the cocoon become sealed, with fertilisation and development taking place inside.
1040:
1001:
878:
1027:
275:
or girdle which is located near the head end of mature individuals. The mouth is on the ventral surface and is overhung by the
439:- commonly the tube worms and the earthworms. Hirudinea contains leeches (Hirudinida), Acanthobdellida, and Branchiobdellida.
522:
1032:
324:
includes strong transverse, longitudinal and diagonal muscles which give the animal great flexibility and extensibility.
327:
Genetic studies have shown the class' genome have gone through an extreme rearrangement, more than any other animals.
479:
Manum, S. B.; Bose, M. N.; Sawyer, R. Y. T. (1991). "Clitellate cocoons in freshwater deposits since the
Triassic".
1102:
1045:
879:
A Series of
Searchable Texts on Earthworm Biodiversity, Ecology and Systematics from Various Regions of the World
962:
949:
967:
873:
1135:
119:
1094:
1055:
1107:
454:
abolish
Oligochaeta as traditionally delimited in favor of a number of smaller monophyletic lineages
400:
605:
Earthworms have ‘completely scrambled’ genomes. Did that enable their ancestors to leave the sea?
363:
can be found in nearly every part of the world, in freshwater, terrestrial, and marine habitats.
1081:
553:"Animal reproductive system: Mechanisms that aid in the union of gametes: Annelids and mollusks"
889:
315:
on each segment; these have muscles attached to their bases and can be extended or retracted.
1076:
627:"Phylogeny of Annelida (Lophotrochozoa): total-evidence analysis of morphology and six genes"
319:
modified into a sucker that usually surrounds the mouth. These segments usually bear several
1068:
988:
936:
927:
8:
1130:
851:
718:
661:
626:
532:
492:
288:
114:
247:– the 'collar' that forms a reproductive cocoon during part of their life cycles. The
1063:
975:
787:
768:
760:
710:
702:
666:
648:
518:
458:
941:
799:
750:
722:
694:
656:
638:
587:
488:
352:
340:
303:
is located). The gonads are located in a few segments near the clitellum, with the
101:
954:
291:
in the skin, especially in the dorsal portion of the anterior end. They also lack
405:
According to modern phylogenetic analyses, the
Clitellata are considered to be a
233:
200:
164:
980:
803:
591:
1124:
912:
764:
706:
652:
461:
while splitting up the traditional "oligochaetes" into monophyletic lineages.
436:
379:
59:
755:
738:
643:
772:
714:
670:
443:
406:
344:
213:
287:
Earthworms and their kin, in the subclass
Oligochaeta, lack eyes but have
1014:
921:
447:
432:
420:
367:
209:
34:
698:
841:(2008): ICZN rules – a farewell to Tubificidae (Annelida, Clitellata).
413:
292:
276:
256:
177:
79:
44:
335:
Clitellates live on land, in freshwater or in the ocean. The subclass
1019:
424:
356:
336:
296:
272:
260:
244:
204:
131:
84:
883:
625:
Zrzavý, Jan; Říha, Pavel; Piálek, Lubomír; Janouškovec, Jan (2009).
1006:
906:
428:
348:
304:
280:
74:
69:
54:
49:
39:
339:(leeches) contains three orders with various habitat preferences.
843:
739:"Illuminating the Base of the Annelid Tree Using Transcriptomics"
252:
237:
151:
89:
64:
513:
Ruppert, Edward E.; Fox, Richard, S.; Barnes, Robert D. (2004).
383:
320:
312:
141:
1089:
785:
576:
409:
360:
308:
271:
Clitellate annelids are segmented worms characterised by the
993:
624:
387:
300:
240:
839:
Erséus, Christer; Wetzel, Mark J. & Gustavsson, Lena
735:
683:
817:
815:
813:
295:and appendages on the prostomium, the body and the
810:
1122:
512:
478:
311:. There are four bundles of one to twenty-five
729:
677:
618:
537:: CS1 maint: multiple names: authors list (
427:. The oligochaetes contain the tubificids (
355:are parasitic on freshwater fishes such as
330:
100:
754:
660:
642:
508:
506:
504:
502:
419:The group is divided into the subclasses
351:, grazing algae from their exoskeletons.
472:
1123:
517:. Cengage Learning. pp. 459–482.
499:
446:, but the clade is embedded among the
888:
887:
792:Molecular Phylogenetics and Evolution
580:Molecular Phylogenetics and Evolution
1095:8759D606-FF5C-970B-C314-06DFFFD1F51F
1056:4b1b43a0-81d0-4105-9ec9-8f6a80161836
457:treat Oligochaeta and Clitellata as
263:and their heads are less developed.
13:
493:10.1111/j.1463-6409.1991.tb00300.x
266:
14:
1147:
867:
545:
515:Invertebrate Zoology, 7th edition
219:
118:
32:
779:
743:Molecular Biology and Evolution
450:. Two approaches are possible:
391:evolutionarily ancestral one).
373:
299:(terminal segment on which the
615:Reichardt (2006): pp.63, 67–68
609:
598:
570:
394:
1:
832:
465:
243:, characterized by having a
7:
804:10.1016/j.ympev.2018.05.001
592:10.1016/j.ympev.2018.05.001
10:
1152:
398:
896:
857:Reichardt, Anna Katharina
198:
193:
115:Scientific classification
113:
108:
99:
23:
631:BMC Evolutionary Biology
401:List of Annelid families
331:Distribution and habitat
644:10.1186/1471-2148-9-189
557:Encyclopedia Britannica
255:. Unlike the class of
861:Systematische Zoologie
307:being anterior to the
251:comprise around 8,000
16:Class of annelid worms
1077:Paleobiology Database
756:10.1093/molbev/msu080
412:embedded deep in the
699:10.1038/nature09864
378:All clitellata are
289:photoreceptor cells
259:, they do not have
578:Rhynchobdellida".
1136:Spiralian classes
1118:
1117:
1064:Open Tree of Life
890:Taxon identifiers
874:Brief description
524:978-81-315-0104-7
481:Zoologica Scripta
226:
225:
1143:
1111:
1110:
1098:
1097:
1085:
1084:
1072:
1071:
1059:
1058:
1049:
1048:
1036:
1035:
1023:
1022:
1010:
1009:
997:
996:
984:
983:
971:
970:
958:
957:
945:
944:
932:
931:
930:
917:
916:
915:
885:
884:
858:
840:
826:
819:
808:
807:
798:(127): 129–134.
783:
777:
776:
758:
749:(6): 1391–1401.
733:
727:
726:
681:
675:
674:
664:
646:
622:
616:
613:
607:
602:
596:
595:
574:
568:
567:
565:
563:
549:
543:
542:
536:
528:
510:
497:
496:
476:
347:with freshwater
341:Branchiobdellida
123:
122:
104:
94:
31:
27:Temporal range:
21:
20:
1151:
1150:
1146:
1145:
1144:
1142:
1141:
1140:
1121:
1120:
1119:
1114:
1106:
1101:
1093:
1088:
1080:
1075:
1067:
1062:
1054:
1052:
1044:
1039:
1031:
1026:
1018:
1013:
1005:
1000:
992:
987:
979:
974:
966:
961:
953:
948:
940:
935:
926:
925:
920:
911:
910:
905:
892:
870:
856:
838:
835:
830:
829:
820:
811:
784:
780:
734:
730:
693:(7336): 95–98.
682:
678:
623:
619:
614:
610:
603:
599:
575:
571:
561:
559:
551:
550:
546:
530:
529:
525:
511:
500:
477:
473:
468:
403:
397:
376:
353:Acanthobdellida
333:
269:
267:Characteristics
217:
207:
203:
201:Branchiobdellae
165:Pleistoannelida
117:
95:
93:
92:
87:
82:
77:
72:
67:
62:
57:
52:
47:
42:
37:
30:Triassic–Recent
29:
28:
25:
17:
12:
11:
5:
1149:
1139:
1138:
1133:
1116:
1115:
1113:
1112:
1099:
1086:
1073:
1060:
1050:
1037:
1024:
1011:
998:
985:
972:
959:
946:
933:
918:
902:
900:
894:
893:
882:
881:
876:
869:
868:External links
866:
865:
864:
854:
834:
831:
828:
827:
809:
778:
728:
676:
617:
608:
597:
569:
544:
523:
498:
470:
469:
467:
464:
463:
462:
455:
396:
393:
380:hermaphrodites
375:
372:
332:
329:
268:
265:
224:
223:
196:
195:
191:
190:
185:
181:
180:
175:
168:
167:
162:
155:
154:
149:
145:
144:
139:
135:
134:
129:
125:
124:
111:
110:
106:
105:
97:
96:
88:
83:
78:
73:
68:
63:
58:
53:
48:
43:
38:
33:
26:
15:
9:
6:
4:
3:
2:
1148:
1137:
1134:
1132:
1129:
1128:
1126:
1109:
1104:
1100:
1096:
1091:
1087:
1083:
1078:
1074:
1070:
1065:
1061:
1057:
1051:
1047:
1042:
1038:
1034:
1029:
1025:
1021:
1016:
1012:
1008:
1003:
999:
995:
990:
986:
982:
977:
973:
969:
964:
960:
956:
951:
947:
943:
938:
934:
929:
923:
919:
914:
908:
904:
903:
901:
899:
895:
891:
886:
880:
877:
875:
872:
871:
862:
855:
853:
849:
846:
845:
837:
836:
824:
818:
816:
814:
805:
801:
797:
793:
789:
782:
774:
770:
766:
762:
757:
752:
748:
744:
740:
732:
724:
720:
716:
712:
708:
704:
700:
696:
692:
688:
680:
672:
668:
663:
658:
654:
650:
645:
640:
636:
632:
628:
621:
612:
606:
601:
593:
589:
585:
581:
573:
558:
554:
548:
540:
534:
526:
520:
516:
509:
507:
505:
503:
494:
490:
486:
482:
475:
471:
460:
456:
453:
452:
451:
449:
445:
442:Hirudinea is
440:
438:
437:Lumbriculidae
434:
430:
426:
422:
417:
415:
411:
408:
402:
392:
389:
385:
381:
371:
369:
366:The subclass
364:
362:
358:
354:
350:
346:
342:
338:
328:
325:
322:
316:
314:
310:
306:
302:
298:
294:
290:
285:
282:
278:
274:
264:
262:
258:
254:
250:
246:
242:
239:
235:
231:
222:
221:
215:
211:
206:
202:
197:
192:
189:
186:
183:
182:
179:
176:
173:
170:
169:
166:
163:
160:
157:
156:
153:
150:
147:
146:
143:
140:
137:
136:
133:
130:
127:
126:
121:
116:
112:
107:
103:
98:
91:
86:
81:
76:
71:
66:
61:
56:
51:
46:
41:
36:
22:
19:
897:
860:
852:PDF fulltext
847:
842:
822:
795:
791:
781:
746:
742:
731:
690:
686:
679:
634:
630:
620:
611:
600:
583:
579:
572:
560:. Retrieved
556:
547:
514:
484:
480:
474:
444:monophyletic
441:
418:
407:monophyletic
404:
377:
374:Reproduction
365:
334:
326:
317:
286:
270:
248:
229:
227:
214:paraphyletic
199:
187:
171:
158:
18:
1015:iNaturalist
922:Wikispecies
586:: 129–134.
448:Oligochaeta
433:Lumbricidae
421:Oligochaeta
414:polychaetes
395:Systematics
368:Oligochaeta
249:clitellates
210:Oligochaeta
194:Subclasses
1131:Clitellata
1125:Categories
955:Clitellata
942:Clitellata
928:Clitellata
898:Clitellata
833:References
637:(1): 189.
562:25 October
487:(4): 347.
459:synonymous
399:See also:
277:prostomium
257:Polychaeta
230:Clitellata
188:Clitellata
178:Sedentaria
109:Earthworm
24:Clitellata
850:: 66–68.
765:1537-1719
707:0028-0836
653:1471-2148
533:cite book
466:Footnotes
425:Hirudinea
345:commensal
337:Hirudinea
297:periproct
293:parapodia
281:gonopores
273:clitellum
261:parapodia
245:clitellum
205:Hirudinea
138:Kingdom:
132:Eukaryota
907:Wikidata
859:(2006):
773:24567512
715:21368831
671:19660115
429:Naididae
386:or both
357:grayling
349:crayfish
218:and see
152:Annelida
148:Phylum:
142:Animalia
128:Domain:
913:Q839350
844:Zootaxa
821:Erséus
723:4428998
662:2732625
384:zygotes
361:Leeches
313:chaetae
309:ovaries
253:species
238:annelid
184:Class:
1082:291060
1069:563197
1053:NZOR:
1033:568832
825:(2008)
823:et al.
771:
763:
721:
713:
705:
687:Nature
669:
659:
651:
521:
435:, and
321:ocelli
305:testes
232:are a
1108:14165
1103:WoRMS
1090:Plazi
1046:42113
1020:63089
968:95135
719:S2CID
410:clade
241:worms
234:class
172:Clade
159:Clade
1041:NCBI
1028:ITIS
1002:GBIF
963:BOLD
848:1744
769:PMID
761:ISSN
711:PMID
703:ISSN
667:PMID
649:ISSN
564:2017
539:link
519:ISBN
423:and
388:ovae
343:are
301:anus
228:The
220:text
35:PreꞒ
1007:255
989:EoL
976:CoL
950:AFD
937:ADW
800:doi
796:127
751:doi
695:doi
691:471
657:PMC
639:doi
588:doi
584:127
489:doi
236:of
212:" (
1127::
1105::
1092::
1079::
1066::
1043::
1030::
1017::
1004::
994:37
991::
981:9H
978::
965::
952::
939::
924::
909::
812:^
794:.
790:.
767:.
759:.
747:31
745:.
741:.
717:.
709:.
701:.
689:.
665:.
655:.
647:.
633:.
629:.
582:.
555:.
535:}}
531:{{
501:^
485:20
483:.
431:,
416:.
359:.
174::
161::
85:Pg
863:.
806:.
802::
775:.
753::
725:.
697::
673:.
641::
635:9
594:.
590::
566:.
541:)
527:.
495:.
491::
216:)
208:"
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.
