421:
315:
731:
299:
488:
307:
27:
326:
Birds reproduce using their cloaca; this occurs during a cloacal kiss in most birds. Birds that mate using this method touch their cloacae together, in some species for only a few seconds, sufficient time for
502:, the genital tract is separate from the anus, but a trace of the original cloaca does remain externally. This is one of the features of marsupials (and monotremes) that suggest their basal nature, as the
76:
256:
The cloacal region is also often associated with a secretory organ, the cloacal gland, which has been implicated in the scent-marking behavior of some reptiles, marsupials, amphibians, and
1069:
Riedelsheimer, B.; Unterberger, Pia; Künzle, H.; Welsch, U. (November 2007). "Histological study of the cloacal region and associated structures in the hedgehog tenrec
Echinops telfairi".
644:
to specialize to take advantage of it while living protected inside the cucumber. At night, many of these species emerge through the anus of the sea cucumber in search of food.
561:
456:, further progress of the fold, dividing the cloaca into urogenital sinus and rectum; the ureter has separated from the Wolffian duct and is shifting anteriorly.
409:
With a few exceptions noted below, mammals have no cloaca. Even in the marsupials that have one, the cloaca is partially subdivided into separate regions for the
420:
869:
626:
during dives. They accomplish this by having a pair of accessory air bladders connected to the cloaca, which can absorb oxygen from the water.
1265:
1236:
1209:
1139:
1022:
979:
863:
836:
807:
711:
684:
533:
divides into a posterior region that becomes part of the anus, and an anterior region that develops depending on sex: in males, it forms the
1356:
734:(Tachyglossus aculeatus setosus): implications for sexual conflict. In Chemical Signals in Vertebrates 13 (pp. 145-166). Springer, Cham.
393:, part of the cloaca remains in the adult to receive the urinary and reproductive ducts, although the anus always opens separately. In
172:
131:
82:
1307:
1155:
Symonds, Matthew R. E. (February 2005). "Phylogeny and life histories of the 'Insectivora': controversies and consequences".
314:
701:
428:, early embryonic stage, showing the cloaca receiving the urinary bladder, the rectum, and the Wolffian duct, as in non-
773:
759:
460:, completion of the fold, showing complete separation of the cloaca into ventral urogenital sinus and dorsal rectum.
1346:
1226:
796:
Michael L. Morrison; Amanda D. Rodewald; Gary
Voelker; Melanie R. Colón; Jonathan F. Prather (3 September 2018).
623:
545:
that receives the urethra and vagina. However, some placental mammals retain a cloaca as adults: those are the
1361:
1336:
492:
20:
743:
Cassell's Latin
Dictionary, Marchant, J.R.V, & Charles, Joseph F., (Eds.), Revised Edition, 1928, p.103
1106:
Morphological evidence supports
Dryolestoid affinities for the living Australian marsupial mole Notoryctes
994:
1341:
560:
Being placental animals, humans have an embryonic cloaca which divides into separate tracts during the
1078:
601:
250:
1351:
893:"Cloacal evaporation: an important and previously undescribed mechanism for avian thermoregulation"
653:
613:
565:
190:
1290:
1180:
778:
1261:
1232:
1205:
1172:
1135:
1129:
1018:
975:
914:
859:
832:
824:
803:
707:
680:
569:
319:
853:
1318:
1164:
1109:
1086:
1051:
945:
904:
542:
538:
530:
526:
437:
382:
143:
102:
44:
783:
441:
390:
31:
436:, later stage, showing the beginning of the fold which divides the cloaca into a ventral
1082:
1254:
1055:
727:
534:
514:
281:
226:
1330:
629:
186:
1184:
241:
mammals, which have two or three separate orifices for evacuation and reproduction.
632:
use cloacal respiration. The constant flow of water through it has allowed various
517:
have a true cloaca. This fact has been used to argue that they are not marsupials.
378:
293:
246:
182:
1199:
1090:
1039:
1012:
797:
674:
1114:
573:
550:
424:
Diagrams to illustrate the changes in the cloaca in mammals during development.
340:
336:
222:
249:
are also sometimes called cloacae. Mating through the cloaca is called cloacal
1168:
637:
356:
298:
198:
1281:
Dunson, William A. (1960). "Aquatic
Respiration in Trionyx spinifer asper".
1131:
Vertebrate
Biology: Systematics, Taxonomy, Natural History, and Conservation
499:
482:
470:
332:
257:
242:
238:
214:
202:
194:
1176:
918:
732:
Chemical cues, hibernation and reproduction in female short-beaked echidnas
754:
506:
from which mammals evolved had a cloaca, and probably so did the earliest
487:
306:
26:
507:
394:
366:
622:, especially those specialized in diving, are highly reliant on cloacal
1294:
597:
503:
414:
398:
386:
331:
to be transferred from the male to the female. For some birds, such as
206:
950:
933:
909:
892:
619:
596:. Some species have modified cloacae for increased gas exchange (see
546:
449:
445:
429:
218:
1308:
The
Straight Dope - Is it true turtles breathe through their butts?
974:. Philadelphia, PA: Holt-Saunders International. pp. 396–399.
362:
One study has looked into birds that use their cloaca for cooling.
554:
486:
419:
344:
328:
313:
305:
297:
269:
234:
230:
210:
25:
891:
Hoffman, Ty C. M.; Walsberg, Glenn E.; DeNardo, Dale F. (2007).
641:
633:
410:
365:
The cloaca in birds may also be referred to as the vent. Among
352:
348:
355:, the males do not use the cloaca for reproduction, but have a
164:
158:
152:
123:
117:
111:
65:
59:
53:
1228:
Comparative
Physiology of the Vertebrate Digestive System
1104:
Chimento, Nicolás; Agnolin, Federico (22 December 2014),
1198:
Stephen J. Divers; Douglas R. Mader (13 December 2005).
999:
A laboratory manual for comparative vertebrate anatomy.
294:
Bird anatomy § Reproductive and urogenital systems
1256:
Turtles, Tortoises & Terrapins: Survivors in Armor
568:
result in persons being born with a cloaca, including
401:, however, all three openings are entirely separated.
369:, the word vent is also a verb meaning "to defecate".
173:
161:
146:
132:
120:
105:
83:
62:
47:
149:
108:
50:
1225:C. Edward Stevens; Ian D. Hume (25 November 2004).
1040:"On the Systematic Position of Notoryctes typhlops"
970:Romer, Alfred Sherwood; Parsons, Thomas S. (1977).
155:
114:
56:
1253:
799:Ornithology: Foundation, Analysis, and Application
562:development of the urinary and reproductive organs
553:(small mammals native to Africa), as well as some
229:) have this orifice, from which they excrete both
1134:. Johns Hopkins University Press. p. 306.
1044:Proceedings of the Zoological Society of London
604:). This is where reproductive activity occurs.
377:Among fish, a true cloaca is present only in
8:
1231:. Cambridge University Press. pp. 23–.
730:, Davies, N. W., & Nicol, S. C. (2016).
473:(egg-laying mammals) possess a true cloaca.
448:, and into a dorsal part which receives the
1319:Aquarium Invertebrates by Rob Toonen, Ph.D.
1113:
949:
908:
537:, while in females, it develops into the
584:In reptiles, the cloaca consists of the
245:openings with analogous purpose in some
185:that serves as the only opening for the
776:. Charlton T. Lewis and Charles Short.
665:
1201:Reptile Medicine and Surgery - E-Book
965:
963:
961:
7:
1011:Mervyn Griffiths (2 December 2012).
829:Owls of the United States and Canada
673:Carl Gans; David Crews (June 1992).
483:Marsupial § Reproductive system
938:The Journal of Experimental Biology
897:The Journal of Experimental Biology
855:Comparative Vertebrate Reproduction
529:have no cloaca. In the embryo, the
92:
1056:10.1111/j.1469-7998.1892.tb06835.x
872:from the original on 26 March 2014
14:
142:
101:
43:
700:R. F. Ewer (11 December 2013).
679:. University of Chicago Press.
276:, "(I) cleanse", thus the noun
1038:Gadow, Hans (20 August 2009).
608:Cloacal respiration in animals
237:; this is in contrast to most
1:
1014:The Biology of the Monotremes
676:Hormones, Brain, and Behavior
1204:. Elsevier Health Sciences.
1091:10.1016/j.mambio.2006.10.012
16:Posterior opening in zoology
1115:10.7287/peerj.preprints.755
760:Online Etymology Dictionary
493:Australian brushtail possum
1380:
1357:Animal reproductive system
1252:Orenstein, Ronald (2001).
1128:Linzey, Donald W. (2020).
831:. JHU Press. p. 151.
611:
480:
291:
18:
1169:10.1017/S1464793104006566
513:Unlike other marsupials,
322:excreting urine in flight
852:Julian Lombardi (1998).
564:. However, a few human
302:Cloaca of a female bird
21:Cloaca (disambiguation)
995:Libbie Henrietta Hyman
495:
491:Cloacal opening in an
461:
444:, Wolffian ducts, and
381:(sharks and rays) and
347:, and some species of
323:
311:
303:
34:
823:Lynch, Wayne (2007).
612:Further information:
490:
481:Further information:
423:
317:
310:Cloaca of a male bird
309:
301:
268:The word is from the
253:and cloacal kissing.
213:, and a few mammals (
197:(if present) of many
29:
1017:. Elsevier Science.
932:Hager, Yfke (2007).
602:reptile reproduction
576:(mermaid syndrome).
566:congenital disorders
19:For other uses, see
1108:, PeerJ PrePrints,
1083:2007MamBi..72..330R
972:The Vertebrate Body
703:Ethology of Mammals
654:Cloaca (embryology)
614:Cloacal respiration
598:reptile respiration
440:which receives the
1157:Biological Reviews
825:"The Cloacal Kiss"
779:A Latin Dictionary
496:
462:
383:lobe-finned fishes
324:
312:
304:
35:
1267:978-1-55209-605-5
1260:. Firefly Books.
1238:978-0-521-61714-7
1211:978-1-4160-6477-0
1141:978-1-42143-733-0
1071:Mammalian Biology
1024:978-0-323-15331-7
981:978-0-03-910284-5
951:10.1242/jeb.02737
934:"Cloacal Cooling"
910:10.1242/jeb.02705
865:978-0-7923-8336-9
838:978-0-8018-8687-4
809:978-1-4214-2471-2
753:Harper, Douglas.
713:978-1-4899-4656-0
686:978-0-226-28124-7
570:persistent cloaca
527:placental mammals
391:ray-finned fishes
320:roseate spoonbill
1369:
1347:Digestive system
1321:
1316:
1310:
1305:
1299:
1298:
1278:
1272:
1271:
1259:
1249:
1243:
1242:
1222:
1216:
1215:
1195:
1189:
1188:
1152:
1146:
1145:
1125:
1119:
1118:
1117:
1101:
1095:
1094:
1066:
1060:
1059:
1035:
1029:
1028:
1008:
1002:
992:
986:
985:
967:
956:
955:
953:
929:
923:
922:
912:
888:
882:
881:
879:
877:
849:
843:
842:
820:
814:
813:
793:
787:
771:
765:
764:
750:
744:
741:
735:
724:
718:
717:
697:
691:
690:
670:
543:urogenital sinus
531:embryonic cloaca
438:urogenital sinus
177:
171:
170:
167:
166:
163:
160:
157:
154:
151:
148:
136:
130:
129:
126:
125:
122:
119:
116:
113:
110:
107:
94:
87:
81:
80:
79:
78:
71:
68:
67:
64:
61:
58:
55:
52:
49:
1379:
1378:
1372:
1371:
1370:
1368:
1367:
1366:
1327:
1326:
1325:
1324:
1317:
1313:
1306:
1302:
1280:
1279:
1275:
1268:
1251:
1250:
1246:
1239:
1224:
1223:
1219:
1212:
1197:
1196:
1192:
1154:
1153:
1149:
1142:
1127:
1126:
1122:
1103:
1102:
1098:
1068:
1067:
1063:
1037:
1036:
1032:
1025:
1010:
1009:
1005:
993:
989:
982:
969:
968:
959:
931:
930:
926:
890:
889:
885:
875:
873:
866:
851:
850:
846:
839:
822:
821:
817:
810:
795:
794:
790:
784:Perseus Project
772:
768:
752:
751:
747:
742:
738:
726:Harris, R. L.,
725:
721:
714:
699:
698:
694:
687:
672:
671:
667:
662:
650:
640:worms and even
616:
610:
582:
523:
515:marsupial moles
485:
479:
467:
442:urinary bladder
407:
375:
296:
290:
266:
227:marsupial moles
181:), is the rear
175:
145:
141:
134:
104:
100:
85:
75:
74:
73:
46:
42:
32:red-tailed hawk
24:
17:
12:
11:
5:
1377:
1376:
1373:
1365:
1364:
1362:Urinary system
1359:
1354:
1349:
1344:
1339:
1337:Animal anatomy
1329:
1328:
1323:
1322:
1311:
1300:
1273:
1266:
1244:
1237:
1217:
1210:
1190:
1147:
1140:
1120:
1096:
1077:(6): 330–341.
1061:
1050:(3): 361–433.
1030:
1023:
1003:
987:
980:
957:
924:
883:
864:
844:
837:
815:
808:
788:
766:
745:
736:
728:Cameron, E. Z.
719:
712:
692:
685:
664:
663:
661:
658:
657:
656:
649:
646:
609:
606:
581:
578:
535:penile urethra
522:
519:
478:
475:
466:
463:
406:
403:
374:
371:
289:
286:
265:
262:
195:urinary tracts
15:
13:
10:
9:
6:
4:
3:
2:
1375:
1374:
1363:
1360:
1358:
1355:
1353:
1350:
1348:
1345:
1343:
1340:
1338:
1335:
1334:
1332:
1320:
1315:
1312:
1309:
1304:
1301:
1296:
1292:
1289:(4): 277–83.
1288:
1284:
1283:Herpetologica
1277:
1274:
1269:
1263:
1258:
1257:
1248:
1245:
1240:
1234:
1230:
1229:
1221:
1218:
1213:
1207:
1203:
1202:
1194:
1191:
1186:
1182:
1178:
1174:
1170:
1166:
1163:(1): 93–128.
1162:
1158:
1151:
1148:
1143:
1137:
1133:
1132:
1124:
1121:
1116:
1111:
1107:
1100:
1097:
1092:
1088:
1084:
1080:
1076:
1072:
1065:
1062:
1057:
1053:
1049:
1045:
1041:
1034:
1031:
1026:
1020:
1016:
1015:
1007:
1004:
1000:
996:
991:
988:
983:
977:
973:
966:
964:
962:
958:
952:
947:
943:
939:
935:
928:
925:
920:
916:
911:
906:
902:
898:
894:
887:
884:
871:
867:
861:
857:
856:
848:
845:
840:
834:
830:
826:
819:
816:
811:
805:
802:. JHU Press.
801:
800:
792:
789:
785:
781:
780:
775:
770:
767:
762:
761:
756:
749:
746:
740:
737:
733:
729:
723:
720:
715:
709:
705:
704:
696:
693:
688:
682:
678:
677:
669:
666:
659:
655:
652:
651:
647:
645:
643:
639:
635:
631:
630:Sea cucumbers
627:
625:
621:
615:
607:
605:
603:
599:
595:
591:
587:
579:
577:
575:
571:
567:
563:
558:
556:
552:
548:
544:
540:
536:
532:
528:
520:
518:
516:
511:
509:
505:
501:
494:
489:
484:
476:
474:
472:
464:
459:
455:
451:
447:
443:
439:
435:
432:vertebrates.
431:
427:
422:
418:
416:
412:
404:
402:
400:
396:
392:
388:
384:
380:
379:elasmobranchs
372:
370:
368:
363:
360:
358:
354:
350:
346:
342:
338:
334:
330:
321:
316:
308:
300:
295:
287:
285:
283:
279:
275:
271:
263:
261:
259:
254:
252:
248:
247:invertebrates
244:
240:
236:
232:
228:
224:
220:
216:
212:
208:
204:
201:animals. All
200:
196:
192:
188:
184:
180:
179:
169:
139:
138:
128:
98:
90:
89:
77:
70:
40:
33:
28:
22:
1342:Bird anatomy
1314:
1303:
1286:
1282:
1276:
1255:
1247:
1227:
1220:
1200:
1193:
1160:
1156:
1150:
1130:
1123:
1105:
1099:
1074:
1070:
1064:
1047:
1043:
1033:
1013:
1006:
1001:1922 (1920s)
998:
990:
971:
941:
937:
927:
903:(5): 741–9.
900:
896:
886:
874:. Retrieved
858:. Springer.
854:
847:
828:
818:
798:
791:
777:
769:
758:
748:
739:
722:
706:. Springer.
702:
695:
675:
668:
628:
617:
593:
589:
585:
583:
559:
551:golden moles
524:
512:
497:
468:
457:
453:
433:
425:
408:
389:and in some
376:
364:
361:
325:
277:
273:
267:
255:
223:golden moles
191:reproductive
96:
38:
36:
30:Cloaca of a
624:respiration
574:sirenomelia
525:Most adult
337:cassowaries
1352:Sex organs
1331:Categories
876:5 December
660:References
638:polychaete
590:proctodeum
521:Placentals
500:marsupials
477:Marsupials
471:monotremes
465:Monotremes
292:See also:
284:, drain".
258:monotremes
251:copulation
215:monotremes
203:amphibians
199:vertebrate
594:coprodeum
539:vestibule
397:and most
395:chimaeras
367:falconers
333:ostriches
264:Etymology
243:Excretory
239:placental
187:digestive
1185:21132866
1177:15727040
944:(5): i.
919:17297135
870:Archived
755:"cloaca"
648:See also
580:Reptiles
504:amniotes
399:teleosts
387:lampreys
207:reptiles
1295:3889486
1079:Bibcode
620:turtles
586:urodeum
547:tenrecs
508:mammals
446:ureters
430:therian
415:urethra
405:Mammals
357:phallus
219:tenrecs
183:orifice
97:cloacae
1293:
1264:
1235:
1208:
1183:
1175:
1138:
1021:
978:
917:
862:
835:
806:
774:cloaca
710:
683:
592:, and
555:shrews
450:rectum
278:cloaca
225:, and
193:, and
39:cloaca
1291:JSTOR
1181:S2CID
642:crabs
618:Some
385:. In
353:ducks
349:swans
345:geese
329:sperm
288:Birds
282:sewer
272:verb
270:Latin
235:feces
231:urine
211:birds
174:kloh-
133:kloh-
84:kloh-
72:
1262:ISBN
1233:ISBN
1206:ISBN
1173:PMID
1136:ISBN
1019:ISBN
976:ISBN
915:PMID
878:2012
860:ISBN
833:ISBN
804:ISBN
708:ISBN
681:ISBN
634:fish
600:and
572:and
549:and
469:The
413:and
411:anus
373:Fish
351:and
341:kiwi
274:cluo
233:and
178:-kee
137:-see
1165:doi
1110:doi
1087:doi
1052:doi
946:doi
942:210
905:doi
901:210
782:on
541:or
498:In
280:, "
140:or
93:pl.
91:),
88:-kə
1333::
1287:16
1285:.
1179:.
1171:.
1161:80
1159:.
1085:.
1075:72
1073:.
1048:60
1046:.
1042:.
997:,
960:^
940:.
936:.
913:.
899:.
895:.
868:.
827:.
757:.
636:,
588:,
557:.
510:.
452:.
417:.
359:.
343:,
339:,
335:,
318:A
260:.
221:,
217:,
209:,
205:,
189:,
176:AY
159:eɪ
153:oʊ
135:AY
118:eɪ
112:oʊ
95::
86:AY
60:eɪ
54:oʊ
37:A
1297:.
1270:.
1241:.
1214:.
1187:.
1167::
1144:.
1112::
1093:.
1089::
1081::
1058:.
1054::
1027:.
984:.
954:.
948::
921:.
907::
880:.
841:.
812:.
786:.
763:.
716:.
689:.
458:D
454:C
434:B
426:A
168:/
165:i
162:k
156:ˈ
150:l
147:k
144:/
127:/
124:i
121:s
115:ˈ
109:l
106:k
103:/
99:(
69:/
66:ə
63:k
57:ˈ
51:l
48:k
45:/
41:(
23:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
