Talk:Animal Development

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Cite this page: Hill, M.A. (2021, June 22) Embryology Animal Development. Retrieved from

Animal Development Time 

Animal Average Days
Bear (Black) 210
Bison 270
Budgerigar 18
Camel 410
cat 65
cow 281
chicken 21
Chimpanzee 236
Chinchilla 111
Coyote 63
deer (Mule) 200
dog 63
Donkey 365
Duck 28
Duck (Muscovy) 35
elephant 660
Elk, Wapiti 255
Ferret 42
Finch 14
Fox 52
Giraffe 425
goat 150
Goose 28
Gorilla 270
Guinea fowl 28
guinea pig 68
Hare 36
Hippopotamus 240
horse 338
Human 274
Leopard 95
Lion 108
Llama 350
Marmoset 150
Mink (European) 41
monkey (Macaque) 180
Moose 240
mouse 20
Muskox 255
Muskrat 29
Nutria, Coypu 130
opossum 12
Otter 285
Panther 90
Parrot 26
Pheasant 24
Pig 114
Pigeon 18
Porcupine 210
Pronghorn 230
Quail 16
rabbit 31
Raccoon 63
rat 21
Reindeer 225
Rhinoceros (African) 480
Seal 330
sheep 150
Shrew 20
Skunk 63
Squirrel (Gray) 40
Swan 35
Tapir 390
Tarsier 182
Tiger 103
Turkey 28
Walrus 450
whale (Sperm) 450
Wolf 63
Woodchuck 31
Animal Notes and Table Data Sources
  • Each animal species has different variations +/- the average values shown in the table.
  • Gestation is the carrying of an animal embryo or fetus inside a female viviparous animal. Except in the case of human gestational age GA.
  • Incubation is the laying of an egg (birds, reptiles, monotremes) with development occurring outside the female animal.

See also - Timeline Comparisons

Animal Development: axolotl | bat | cat | chicken | cow | dog | dolphin | echidna | fly | frog | goat | grasshopper | guinea pig | hamster | horse | kangaroo | koala | lizard | medaka | mouse | opossum | pig | platypus | rabbit | rat | sea squirt | sea urchin | sheep | worm | zebrafish | life cycles | development timetable | development models | K12
Historic Embryology  
1897 Pig | 1900 Chicken | 1901 Lungfish | 1904 Sand Lizard | 1905 Rabbit | 1906 Deer | 1907 Tarsiers | 1908 Human | 1909 Northern Lapwing | 1909 South American and African Lungfish | 1910 Salamander | 1951 Frog | Embryology History | Historic Disclaimer

Additional Data Sources

  • Theiler K. The House Mouse: Atlas of Mouse Development (1972, 1989) Springer-Verlag, NY. Online
  • Witschi E. Rat Development. In: Growth Including Reproduction and Morphological Development. (1962) Altman PL. and Dittmer DS. ed. Fed. Am. Soc. Exp. Biol., Washington DC, pp. 304-314.
  • The Genetics of the Dog. E Ostrander, E. and Ruvinsky, A. ISBN: 9781845939403 (2012)
  • Merck Veterinary Manual. Aiello, S.E. and Moses, M.A. (ed) ISBN: 0911910506 (2013) Online
  • Witschi, E. (1962) Development: Rat. In: Growth Including Reproduction and Morphological Development. Altman, P. L. , and D. S. Dittmer, ed. Fed. Am. Soc. Exp. Biol., Washington DC, pp. 304-314.
Cattle Gestation Periods (Bovine Development)  
Breed Average Days
(±7–10 days)
Angus 281
Ayrshire 279
Brahman 292
Brown Swiss 290
Charolais 289
Guernsey 283
Hereford 285
Holstein 279
Jersey 279
Limousin 289
Shorthorn 282
Simmental 289
Avian Incubation Periods  
Bird Days
Budgerigar 18
Chicken 21
Duck 28
Finch 14
Goose 28
Guinea fowl 28
Muscovy duck 35
Parrot 26
Pheasant 24
Pigeon 18
Quail 16
Swan 35
Turkey 28

Brain Museum - histology images from different species


Octopus Development

Primate Development


Representation of anatomy in online atlases and databases: a survey and collection of patterns for interface design

BMC Dev Biol. 2016 May 21;16(1):18. doi: 10.1186/s12861-016-0116-y.

Clarkson MD1.


BACKGROUND: A large number of online atlases and databases have been developed to mange the rapidly growing amount of data describing embryogenesis. As these community resources continue to evolve, it is important to understand how representations of anatomy can facilitate the sharing and integration of data. In addition, attention to the design of the interfaces is critical to make online resources useful and usable. RESULTS: I first present a survey of online atlases and gene expression resources for model organisms, with a focus on methods of semantic and spatial representation of anatomy. A total of 14 anatomical atlases and 21 gene expression resources are included. This survey demonstrates how choices in semantic representation, in the form of ontologies, can enhance interface search functions and provide links between relevant information. This survey also reviews methods for spatially representing anatomy in online resources. I then provide a collection of patterns for interface design based on the atlases and databases surveyed. These patterns include methods for displaying graphics, integrating semantic and spatial representations, organizing information, and querying databases to find genes expressed in anatomical structures. CONCLUSIONS: This collection of patterns for interface design will assist biologists and software developers in planning the interfaces of new atlases and databases or enhancing existing ones. They also show the benefits of standardizing semantic and spatial representations of anatomy by demonstrating how interfaces can use standardization to provide enhanced functionality. KEYWORDS: Anatomy; Atlas; Database; Interface; Ontology PMID 27206491 PMCID: PMC4875762 DOI: 10.1186/s12861-016-0116-y


A higher level classification of all living organisms

PLoS One. 2015 Apr 29;10(4):e0119248. doi: 10.1371/journal.pone.0119248. eCollection 2015.

Ruggiero MA1, Gordon DP2, Orrell TM1, Bailly N3, Bourgoin T4, Brusca RC5, Cavalier-Smith T6, Guiry MD7, Kirk PM8.


We present a consensus classification of life to embrace the more than 1.6 million species already provided by more than 3,000 taxonomists' expert opinions in a unified and coherent, hierarchically ranked system known as the Catalogue of Life (CoL). The intent of this collaborative effort is to provide a hierarchical classification serving not only the needs of the CoL's database providers but also the diverse public-domain user community, most of whom are familiar with the Linnaean conceptual system of ordering taxon relationships. This classification is neither phylogenetic nor evolutionary but instead represents a consensus view that accommodates taxonomic choices and practical compromises among diverse expert opinions, public usages, and conflicting evidence about the boundaries between taxa and the ranks of major taxa, including kingdoms. Certain key issues, some not fully resolved, are addressed in particular. Beyond its immediate use as a management tool for the CoL and ITIS (Integrated Taxonomic Information System), it is immediately valuable as a reference for taxonomic and biodiversity research, as a tool for societal communication, and as a classificatory "backbone" for biodiversity databases, museum collections, libraries, and textbooks. Such a modern comprehensive hierarchy has not previously existed at this level of specificity. PMID 25923521


A Comparison of the Histological Structure of the Placenta in Experimental Animals

J Toxicol Pathol. 2014 Apr;27(1):11-18. Epub 2014 Apr 30.

Furukawa S1, Kuroda Y1, Sugiyama A2.


The primary function of the placenta is to act as an interface between the dam and fetus. The anatomic structure of the chorioallantoic placenta in eutherian mammals varies between different animal species. The placental types in eutherian mammals are classified from various standpoints based on the gross shape, the histological structure of the materno-fetal interface, the type of materno-fetal interdigitation, etc. Particularly, the histological structure is generally considered one of the most useful and instructive classifications for functionally describing placental type. In this system, three main types are recognized according to the cell layers comprising the interhemal area: (1) epitheliochorial type (horses, pigs and ruminants), (2) endotheliochorial type (carnivores) and (3) hemochorial type (primates, rodents and rabbits). The number of cell layers in the interhemal area is considered to modify the transfer of nutrients between maternal and fetal blood and is one of the important factors with respect to the difference in placental permeability between animal species. Therefore, in reproductive and developmental toxicity studies, careful attention should be paid to the histological structure of the interhemal area when extrapolating information concerning placental transfer characteristics to different animal species. KEYWORDS: cynomolgus monkey, dog, minipig, placenta, rabbit, rat

PMID 24791062



Standardised classification of pre-release development in male-brooding pipefish, seahorses, and seadragons (Family Syngnathidae)

BMC Dev Biol. 2012 Dec 29;12:39. doi: 10.1186/1471-213X-12-39.

Sommer S, Whittington CM, Wilson AB. Source Institute of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, Zürich, CH-8057, Switzerland. Abstract ABSTRACT: BACKGROUND: Members of the family Syngnathidae share a unique reproductive mode termed male pregnancy. Males carry eggs in specialised brooding structures for several weeks and release free-swimming offspring. Here we describe a systematic investigation of pre-release development in syngnathid fishes, reviewing available data for 17 species distributed across the family. This work is complemented by in-depth examinations of the straight-nosed pipefish Nerophis ophidion, the black-striped pipefish Syngnathus abaster, and the potbellied seahorse Hippocampus abdominalis. RESULTS: We propose a standardised classification of early syngnathid development that extends from the activation of the egg to the release of newborn. The classification consists of four developmental periods - early embryogenesis, eye development, snout formation, and juvenile - which are further divided into 11 stages. Stages are characterised by morphological traits that are easily visible in live and preserved specimens using incident-light microscopy. CONCLUSIONS: Our classification is derived from examinations of species representing the full range of brooding-structure complexity found in the Syngnathidae, including tail-brooding as well as trunk-brooding species, which represent independent evolutionary lineages. We chose conspicuous common traits as diagnostic features of stages to allow for rapid and consistent staging of embryos and larvae across the entire family. In view of the growing interest in the biology of the Syngnathidae, we believe that the classification proposed here will prove useful for a wide range of studies on the unique reproductive biology of these male-brooding fish.

PMID 23273265

Seahorse Development


Approaches and species in the history of vertebrate embryology

Methods Mol Biol. 2011;770:1-20.

Hopwood N. Source Department of History and Philosophy of Science, University of Cambridge, Cambridge, UK. Abstract Recent debates about model organisms echo far into the past; taking a longer view adds perspective to present concerns. The major approaches in the history of research on vertebrate embryos have tended to exploit different species, though there are long-term continuities too. Early nineteenth-century embryologists worked on surrogates for humans and began to explore the range of vertebrate embryogenesis; late nineteenth-century Darwinists hunted exotic ontogenies; around 1900 experimentalists favored living embryos in which they could easily intervene; reproductive scientists tackled farm animals and human beings; after World War II developmental biologists increasingly engineered species for laboratory life; and proponents of evo-devo have recently challenged the resulting dominance of a few models. Decisions about species have depended on research questions, biological properties, supply lines, and, not least, on methods. Nor are species simply chosen; embryology has transformed them even as they have profoundly shaped the science.

PMID 21805259



Axolotl Development - (Ambystoma mexicanum) A salamander where the larvae do not undergo metamorphosis and adults remain gilled and aquatic. The ability to regenrate limbs has been used to study developmental pattern formation and nerve regeneration. Also used to investigate neural crest migration.


Baboon Development


Elephant Development Elephant and calf

Obstetrics in elephants

Theriogenology. 2008 Jul 15;70(2):131-44. Epub 2008 May 21

Hermes R, Saragusty J, Schaftenaar W, Göritz F, Schmitt DL, Hildebrandt TB.

Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany. Abstract Obstetrics, one of the oldest fields in veterinary medicine, is well described and practiced in domestic and exotic animals. However, when providing care during elephant birth or dystocia, veterinary intervention options differ greatly from any domestic species, and are far more limited due to the dimensions and specific anatomy of the elephant reproductive tract. In addition, aging of captive elephant populations and advanced age of primiparous females make active birth management increasingly important. Intrauterine infection, uterine inertia and urogenital tract pathologies are emerging as major causes for dystocia, often leading to foetal and dam death. This paper reviews the current knowledge on elephant birth and the factors associated with dystocia. It then summarises recommendations for birth and dystocia management. As Caesarean section, the most common ultima ratio in domestic animal obstetrics, is lethal and therefore not an option in the elephant, non-invasive medical treatment, induction of the Fergusson reflex or the conscious decision to leave a retained foetus until it is expelled voluntarily, are key elements in elephant obstetrics. Surgical strategies such as episiotomy and foetotomy are sometimes inevitable in order to try to save the life of the dam, however, these interventions result in chronic post-surgical complications or even fatal outcome. Limited reliable data on serum calcium concentrations, and pharmacokinetics and effect of exogenous oestrogen, oxytocin, and prostaglandins during birth provide the scope of future research, necessary to advance scientific knowledge on obstetrics in elephants.

PMID: 18499243

Foetal age determination and development in elephants

Hildebrandt T, Drews B, Gaeth AP, Goeritz F, Hermes R, Schmitt D, Gray C, Rich P, Streich WJ, Short RV, Renfree MB. Proc Biol Sci. 2007 Feb 7;274(1608):323-31.

Elephants have the longest pregnancy of all mammals, with an average gestation of around 660 days, so their embryonic and foetal development have always been of special interest. Hitherto, it has only been possible to estimate foetal ages from theoretical calculations based on foetal mass. The recent development of sophisticated ultrasound procedures for elephants has now made it possible to monitor the growth and development of foetuses of known gestational age conceived in captivity from natural matings or artificial insemination. We have studied the early stages of pregnancy in 10 captive Asian and 9 African elephants by transrectal ultrasound. Measurements of foetal crown-rump lengths have provided the first accurate growth curves, which differ significantly from the previous theoretical estimates based on the cube root of foetal mass. We have used these to age 22 African elephant foetuses collected during culling operations. Pregnancy can be first recognized ultrasonographically by day 50, the presumptive yolk sac by about day 75 and the zonary placenta by about day 85. The trunk is first recognizable by days 85-90 and is distinct by day 104, while the first heartbeats are evident from around day 80. By combining ultrasonography and morphology, we have been able to produce the first reliable criteria for estimating gestational age and ontological development of Asian and African elephant foetuses during the first third of gestation.

PMID: 17164195

Grasshopper Development

Grasshopper Development - A species used in neural development studies.


Embryonic development of the self-fertilizing mangrove killifish Kryptolebias marmoratus

Dev Dyn. 2011 Jul;240(7):1694-704. doi: 10.1002/dvdy.22668.

Mourabit S, Edenbrow M, Croft DP, Kudoh T. Source Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom. Abstract The mangrove killifish, Kryptolebias marmoratus, is a self-fertilizing vertebrate offering vast potential as a model species in many biological disciplines. Previous studies have defined developmental stages but lacked visual representations of the various embryonic structures. We offer detailed photographic images of K. marmoratus development with revised descriptions. An improved dechorionation method was developed to provide high resolution photographs, in addition to a microinjection technique enabling cell marking in the yolk syncytial layer. Embryos were also treated with PTU (1-phenyl 2-thiourea), an inhibitor of melanogenesis, to provide optical transparency revealing internal structures in late stages of development. Chemical exposures (PTU and retinoic acid) demonstrated that K. marmoratus embryos were sensitive to chemicals, illustrating further their usefulness in developmental biology studies. Our data suggest that K. marmoratus embryos are easily used and manipulated, supporting the use of this hermaphroditic vertebrate as a strong comparative model system in embryology, evolution, genetics, environmental and medical biology.

Copyright © 2011 Wiley-Liss, Inc.

PMID 21674684


Koala Development


An embryonic staging table for in ovo development of Eublepharis macularius, the leopard gecko. Wise PA, Vickaryous MK, Russell AP. Anat Rec (Hoboken). 2009 Aug;292(8):1198-212. PMID: 19645023


Monkey Development - a model used for primate development studies.

Salmon Development

Salmon Development

Sea Urchin Development

Sea Urchin Development - A species used to study very early development from fertilization onward.

Shark Development

Shark Development



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Guinea Pig

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Embryo Staging Systems



Medaka Fish