393:
901:
303:(Greek poikilos – 'various, spotted', and therme – 'heat) whose internal temperature varies considerably. Poikilotherms have to survive and adapt to environmental stress. One of the most important stressors is temperature change, which can lead to alterations in membrane lipid order and can cause protein unfolding and denaturation at elevated temperatures. It is the opposite of a
204:
36:
542:
homeotherms and poikilotherms have similar niches, and compete, the homeotherm can often drive poikilothermic competitors to extinction, because homeotherms can gather food for a greater fraction of each day and in more effective, specialized ways (e.g. chimpanzees actively seeking out and collecting army ants with sticks versus the typical poikilotherm sit-and-wait strategy).
85:
541:
This difference in energy requirement also means that a given food source can support a greater density of poikilothermic animals than homeothermic animals. This is reflected in the predator-prey ratio which is usually higher in poikilothermic fauna compared to homeothermic ones. However, when
473:
are unable to regulate heat. A behavioral adaptation to combat this is incubation, where to maintain the internal temperatures of eggs, the queen and her workers will incubate the brood almost constantly, by warming their abdomens and touching them to the eggs. The bumblebee generates heat by
517:, although they are homeotherms, thermoregulate using a method termed "temperature cycling" to conserve energy. In hot deserts, they allow their body temperature to rise during the day and fall during the night, adjusting their body temperature to cycle over approximately 6 °C.
708:
Sherwin, C.M. (2010). The
Husbandry and Welfare of Non-traditional Laboratory Rodents. In "UFAW Handbook on the Care and Management of Laboratory Animals", R. Hubrecht and J. Kirkwood (Eds). Wiley-Blackwell. Chapter 25, pp.
412:
Poikilotherm animals must be able to function over a wider range of temperatures than homeotherms. The speed of most chemical reactions vary with temperature, and in order to function poikilotherms may have four to ten
691:
Daly, T.J.M., Williams, L.A. and
Buffenstein, R., (1997). Catecholaminergic innervation of interscapular brown adipose tissue in the naked mole-rat (Heterocephalus glaber). Journal of Anatomy, 190: 321-326.
444:
is generally beyond poikilotherm animals. The metabolism of poikilotherms favors strategies such as sit-and-wait hunting over chasing prey for larger animals with high movement cost. As they do not use their
330:
are poikilothermic. However some ectotherms remain in temperature-constant environments to the point that they are actually able to maintain a constant internal temperature and are considered
866:
Steen, J.B, Steen, H. & Stenseth, N.C. (1991): Population
Dynamics of Poikilotherm and Homeotherm Vertebrates: Effects of Food Shortage. OICOS Vol. 60, No 2 (March, 1991), pp 269-272.
190:
511:. Body volume increases proportionally faster than does body surface, with increasing size; and less body surface area per unit body volume tends to minimise heat loss.
480:
mounds are usually oriented in a north–south direction so that they absorb as much heat as possible around dawn and dusk and minimise heat absorption around noon.
408:) as a function of core body temperature. The homeotherm has a much higher output, but can only function over a very narrow range of body temperatures.
334:. It is this distinction that often makes the term "poikilotherm" more useful than the vernacular "cold-blooded", which is sometimes used to refer to
449:
to heat or cool themselves, total energy requirement over time is low. For the same body weight, poikilotherms need only 5 to 10% of the energy of
530:
often have much shorter generations than homeotherms: weeks rather than years. Such applies even to animals with similar ecological roles such as
183:
417:
systems that operate at different temperatures for an important chemical reaction. As a result, poikilotherms often have larger, more complex
851:
820:
661:
176:
52:
494:. They also have their swimming muscles near the center of their bodies instead of near the surface, which minimises heat loss.
341:
Poikilothermic animals include types of vertebrate animals, specifically some fish, amphibians, and reptiles, as well as many
429:
are a notable example of this effect, though their complex development is also an important factor in their large genome.
905:
879:
923:
928:
526:
It is comparatively easy for a poikilotherm to accumulate enough energy to reproduce. Poikilotherms at the same
832:
Campbell, N. A., Reece, J. B., et al. (2002). Biology. 6th edition. Benjamin / Cummings
Publishing Company.
470:
601:
Guschina, Irina A.; Harwood, John L. (2006). "Mechanisms of temperature adaptation in poikilotherms".
555:
579:
505:
323:
794:
736:
634:
308:
847:
816:
786:
657:
626:
618:
559:
778:
728:
693:
610:
422:
222:
75:
811:
Willmer, P., Stone, G., & Johnston, I. A. (2000): Environmental physiology of animals.
392:
571:
154:
139:
677:"Body size shifts influence effects of increasing temperatures on ectotherm metabolism".
754:
Cavalier-Smith, T. (1991). "Coevolution of vertebrate genome, cell, and nuclear sizes".
697:
346:
900:
578:
is considered a poikilothermic state in humans. Poikilothermia is one of the signs of
211:
is a poikilotherm and is able to function over a wide range of body core temperatures.
917:
527:
497:
487:
362:
164:
144:
798:
638:
490:, which helps keep heat inside the body, and minimises the loss of heat through the
466:
bask in the sun in the early morning and late evening, and seek shelter around noon.
342:
159:
149:
134:
124:
119:
614:
486:
are able to warm their entire bodies through a heat exchange mechanism called the
563:
374:), meaning "varied," ultimately from a root meaning "dappled" or "painted," and
311:
208:
114:
769:
Ryan
Gregory, T. (1 January 2002). "Genome size and developmental complexity".
782:
501:
450:
446:
432:
Because their metabolism is variable and generally below that of homeothermic
401:
331:
319:
304:
203:
17:
622:
575:
508:
335:
327:
129:
104:
99:
94:
790:
630:
84:
315:
719:
Britton, S. W.; Atkinson, W. E. (1938). "Poikilothermism in the Sloth".
867:
740:
567:
477:
433:
500:
means growing to large size in order to reduce heat loss, such as in
437:
418:
414:
397:
300:
732:
535:
514:
463:
441:
405:
391:
350:
202:
656:. Principal ill. Viola Hildebrand. New York: Wiley. p. 429.
322:. Usually the fluctuations are a consequence of variation in the
491:
483:
426:
550:
In medicine, loss of normal thermoregulation is referred to as
531:
264:
231:
29:
288:
285:
252:
249:
279:
243:
237:
474:
shivering flight muscles even though they are not flying.
318:, it is generally only applied to animals, and mostly to
273:
27:
Organism with considerable internal temperature variation
353:
are some of the rare mammals which are poikilothermic.
756:
Symposium on the
Evolution of Terrestrial Vertebrates
282:
270:
246:
234:
276:
261:
240:
228:
846:. Sunderland, MA: Sinauer Associates. p. 270.
291:
267:
255:
225:
436:, sustained high-energy activities like powered
314:. While the term in principle can apply to all
462:Some adaptations are behavioral. Lizards and
396:Sustained energy output of a poikilotherm (a
184:
8:
652:Milton Hildebrand; G. E. Goslow Jr. (2001).
379:
369:
882:(2009). "3". In Teofilo Lee-Chiong (ed.).
191:
177:
71:
49:Article could have a lot more information.
45:needs attention from an expert in biology
440:in large animals or maintaining a large
590:
74:
55:may be able to help recruit an expert.
7:
596:
594:
698:10.1046/j.1469-7580.1997.19030321.x
25:
324:ambient environmental temperature
899:
654:Analysis of vertebrate structure
221:
83:
34:
679:Global Ecology and Biogeography
886:. Wiley-Blackwell. p. 12.
1:
904:The dictionary definition of
615:10.1016/j.febslet.2006.06.066
421:than homeotherms in the same
457:Adaptations in poikilotherms
307:, an animal which maintains
47:. The specific problem is:
945:
884:Sleep Medicine Essentials
380:
370:
783:10.1023/A:1016032400147
842:Hill, Richard (2016).
554:. This can be seen in
471:yellow-faced bumblebee
409:
361:The term derives from
212:
815:, London. 644 pages,
395:
206:
721:Journal of Mammalogy
556:compartment syndrome
580:acute limb ischemia
384:), meaning "heat".
326:. Many terrestrial
53:WikiProject Biology
560:sedative-hypnotics
410:
213:
924:Animal physiology
844:Animal Physiology
813:Blackwell Science
609:(23): 5477–5483.
201:
200:
70:
69:
16:(Redirected from
936:
929:Thermoregulation
903:
888:
887:
876:
870:
864:
858:
857:
839:
833:
830:
824:
809:
803:
802:
766:
760:
759:
751:
745:
744:
716:
710:
706:
700:
689:
683:
682:
674:
668:
667:
649:
643:
642:
598:
558:and with use of
469:The eggs of the
423:ecological niche
383:
382:
373:
372:
338:more generally.
298:
297:
294:
293:
290:
287:
284:
281:
278:
275:
272:
269:
266:
263:
258:
257:
254:
251:
248:
245:
242:
239:
236:
233:
230:
227:
193:
186:
179:
87:
76:Thermoregulation
72:
65:
62:
56:
38:
37:
30:
21:
944:
943:
939:
938:
937:
935:
934:
933:
914:
913:
896:
891:
878:
877:
873:
865:
861:
854:
841:
840:
836:
831:
827:
810:
806:
768:
767:
763:
753:
752:
748:
733:10.2307/1374287
718:
717:
713:
707:
703:
690:
686:
676:
675:
671:
664:
651:
650:
646:
600:
599:
592:
588:
572:chloral hydrate
548:
524:
459:
390:
359:
260:
224:
220:
197:
160:Tachymetabolism
155:Bradymetabolism
140:Thermostability
66:
60:
57:
51:
39:
35:
28:
23:
22:
15:
12:
11:
5:
942:
940:
932:
931:
926:
916:
915:
912:
911:
895:
894:External links
892:
890:
889:
880:Leon Rosenthal
871:
859:
853:978-1605354712
852:
834:
825:
804:
777:(1): 131–146.
761:
746:
711:
701:
684:
669:
662:
644:
589:
587:
584:
552:poikilothermia
547:
544:
523:
520:
519:
518:
512:
495:
481:
475:
467:
458:
455:
389:
386:
358:
355:
347:naked mole-rat
345:animals. The
199:
198:
196:
195:
188:
181:
173:
170:
169:
168:
167:
162:
157:
152:
147:
142:
137:
132:
127:
122:
117:
112:
107:
102:
97:
89:
88:
80:
79:
68:
67:
42:
40:
33:
26:
24:
18:Poikilothermic
14:
13:
10:
9:
6:
4:
3:
2:
941:
930:
927:
925:
922:
921:
919:
910:at Wiktionary
909:
908:
902:
898:
897:
893:
885:
881:
875:
872:
869:
863:
860:
855:
849:
845:
838:
835:
829:
826:
822:
821:0-632-03517-X
818:
814:
808:
805:
800:
796:
792:
788:
784:
780:
776:
772:
765:
762:
757:
750:
747:
742:
738:
734:
730:
726:
722:
715:
712:
705:
702:
699:
695:
688:
685:
680:
673:
670:
665:
663:0-471-29505-1
659:
655:
648:
645:
640:
636:
632:
628:
624:
620:
616:
612:
608:
604:
597:
595:
591:
585:
583:
581:
577:
573:
569:
565:
561:
557:
553:
545:
543:
539:
537:
533:
529:
528:trophic level
521:
516:
513:
510:
507:
503:
499:
498:Gigantothermy
496:
493:
489:
488:rete mirabile
485:
482:
479:
476:
472:
468:
465:
461:
460:
456:
454:
452:
448:
443:
439:
435:
430:
428:
424:
420:
416:
407:
403:
399:
394:
387:
385:
377:
367:
364:
356:
354:
352:
348:
344:
339:
337:
333:
329:
325:
321:
317:
313:
310:
306:
302:
296:
218:
210:
205:
194:
189:
187:
182:
180:
175:
174:
172:
171:
166:
165:Thermogenesis
163:
161:
158:
156:
153:
151:
148:
146:
145:Gigantothermy
143:
141:
138:
136:
133:
131:
128:
126:
123:
121:
118:
116:
113:
111:
108:
106:
103:
101:
98:
96:
93:
92:
91:
90:
86:
82:
81:
77:
73:
64:
54:
50:
46:
43:This article
41:
32:
31:
19:
907:poikilotherm
906:
883:
874:
862:
843:
837:
828:
812:
807:
774:
770:
764:
755:
749:
724:
720:
714:
704:
687:
678:
672:
653:
647:
606:
603:FEBS Letters
602:
564:barbiturates
551:
549:
540:
525:
431:
411:
375:
365:
360:
343:invertebrate
340:
332:homeothermic
217:poikilotherm
216:
214:
150:Kleptothermy
135:Thermolabile
120:Heterothermy
110:Poikilotherm
109:
58:
48:
44:
546:In medicine
502:sea turtles
451:homeotherms
447:metabolisms
320:vertebrates
312:homeostasis
209:common frog
115:Homeothermy
918:Categories
402:homeotherm
388:Physiology
336:ectotherms
328:ectotherms
305:homeotherm
125:Stenotherm
78:in animals
727:(1): 94.
623:1873-3468
576:REM sleep
509:megafauna
357:Etymology
316:organisms
130:Eurytherm
105:Mesotherm
100:Endotherm
95:Ectotherm
61:July 2016
799:24565842
791:12188045
771:Genetica
758:: 51–86.
639:25197515
631:16824520
400:) and a
371:ποικίλος
366:poikilos
299:) is an
868:summary
741:1374287
709:359-369
568:ethanol
522:Ecology
506:ice-age
478:Termite
434:animals
419:genomes
376:thermos
309:thermal
850:
819:
797:
789:
739:
660:
637:
629:
621:
570:, and
536:snakes
515:Camels
464:snakes
438:flight
415:enzyme
398:lizard
381:θερμός
301:animal
795:S2CID
737:JSTOR
635:S2CID
586:Notes
562:like
492:gills
442:brain
427:Frogs
406:mouse
363:Greek
351:sloth
848:ISBN
817:ISBN
787:PMID
658:ISBN
627:PMID
619:ISSN
534:and
532:cats
504:and
484:Tuna
349:and
207:The
779:doi
775:115
729:doi
694:doi
611:doi
607:580
404:(a
289:ɜːr
253:ɜːr
920::
793:.
785:.
773:.
735:.
725:19
723:.
633:.
625:.
617:.
605:.
593:^
582:.
574:.
566:,
538:.
453:.
425:.
265:ɔɪ
232:ɔɪ
215:A
856:.
823:.
801:.
781::
743:.
731::
696::
681:.
666:.
641:.
613::
378:(
368:(
295:/
292:m
286:θ
283:ˌ
280:ə
277:l
274:ɪ
271:k
268:ˈ
262:p
259:,
256:m
250:θ
247:ˌ
244:ə
241:l
238:ə
235:k
229:p
226:ˈ
223:/
219:(
192:e
185:t
178:v
63:)
59:(
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
