Portal:Animals/Animals topics
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- Animal colouration
- Animal rights
- Anthrozoology
- Ethology
- Fauna
- Flying and gliding animals
- Invertebrate
- Neuroethology
- Vermin
- Worm
- Zoology
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The following table lists estimated numbers of described extant species for the animal groups with the largest numbers of species,{{cite journal |last=Zhang |first=Zhi-Qiang |title=Animal biodiversity: An update of classification and diversity in 2013. In: Zhang, Z.-Q. (Ed.) Animal Biodiversity: An Outline of Higher-level Classification and Survey of Taxonomic Richness (Addenda 2013) |journal=Zootaxa |volume=3703 |issue=1 |date=2013-08-30 |doi=10.11646/zootaxa.3703.1.3 |url=https://biotaxa.org/Zootaxa/article/download/zootaxa.3703.1.3/4273 |page=5 |access-date=2 March 2018 |archive-url=https://web.archive.org/web/20190424154926/https://biotaxa.org/Zootaxa/article/download/zootaxa.3703.1.3/4273 |archive-date=24 April 2019 |url-status=live }} along with their principal habitats (terrestrial, fresh water,{{cite book |last1=Balian |first1=E. V. |last2=Lévêque |first2=C. |last3=Segers|first3=H.|first4=K. |last4=Martens |title=Freshwater Animal Diversity Assessment |url=https://books.google.com/books?id=Dw4H6DBHnAgC&pg=PA628 |year=2008 |publisher=Springer |isbn=978-1-4020-8259-7 |page=628}} and marine),{{cite web |last1=Hogenboom |first1=Melissa |title=There are only 35 kinds of animal and most are really weird |url=https://www.bbc.co.uk/earth/story/20150325-all-animal-life-in-35-photos |publisher=BBC Earth |access-date=2 March 2018 |archive-url=https://web.archive.org/web/20180810141811/http://www.bbc.co.uk/earth/story/20150325-all-animal-life-in-35-photos|archive-date=10 August 2018|url-status=live}} and free-living or parasitic ways of life.{{cite book |last=Poulin |first=Robert |authorlink=Robert Poulin (zoologist) |title=Evolutionary Ecology of Parasites |publisher=Princeton University Press |year=2007 |isbn=978-0-691-12085-0 |page=[https://archive.org/details/evolutionaryecol0000poul/page/6 6] |url=https://archive.org/details/evolutionaryecol0000poul/page/6 }} Species estimates shown here are based on numbers described scientifically; much larger estimates have been calculated based on various means of prediction, and these can vary wildly. For instance, around 25,000–27,000 species of nematodes have been described, while published estimates of the total number of nematode species include 10,000–20,000; 500,000; 10 million; and 100 million.{{cite book |last1=Felder |first1=Darryl L. |last2=Camp |first2=David K. |title=Gulf of Mexico Origin, Waters, and Biota: Biodiversity |url=https://books.google.com/books?id=CphA8hiwaFIC&pg=RA1-PA1111 |year=2009 |publisher=Texas A&M University Press |isbn=978-1-60344-269-5 |page=1111}} Using patterns within the taxonomic hierarchy, the total number of animal species—including those not yet described—was calculated to be about 7.77 million in 2011.{{cite web |title=How many species on Earth? About 8.7 million, new estimate says |url=https://www.sciencedaily.com/releases/2011/08/110823180459.htm |accessdate=2 March 2018 |date=24 August 2011 |archive-url=https://web.archive.org/web/20180701164954/https://www.sciencedaily.com/releases/2011/08/110823180459.htm |archive-date=1 July 2018 |url-status=live }}{{cite journal |last1=Mora |first1=Camilo |last2=Tittensor |first2=Derek P. |last3=Adl |first3=Sina |last4=Simpson |first4=Alastair G.B. |last5=Worm |first5=Boris |editor-last=Mace |editor-first=Georgina M. |title=How Many Species Are There on Earth and in the Ocean? |journal=PLOS Biology |volume=9 |issue=8 |date=2011-08-23 |doi=10.1371/journal.pbio.1001127 |page=e1001127 |pmid=21886479 |pmc=3160336 |doi-access=free }}{{efn|The application of DNA barcoding to taxonomy further complicates this; a 2016 barcoding analysis estimated a total count of nearly 100,000 insect species for Canada alone, and extrapolated that the global insect fauna must be in excess of 10 million species, of which nearly 2 million are in a single fly family known as gall midges (Cecidomyiidae).{{cite journal |last1=Hebert |first1=Paul D.N. |last2=Ratnasingham |first2=Sujeevan |last3=Zakharov |first3=Evgeny V. |last4=Telfer |first4=Angela C. |last5=Levesque-Beaudin |first5=Valerie |last6=Milton |first6=Megan A. |last7=Pedersen |first7=Stephanie |last8=Jannetta |first8=Paul |last9=deWaard |first9=Jeremy R. |title=Counting animal species with DNA barcodes: Canadian insects |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |date=1 August 2016 |volume=371 |issue=1702 |pages=20150333 |doi=10.1098/rstb.2015.0333 |pmid=27481785 |pmc=4971185}}}}
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