[1] There are anecdotal reports of grieving pets displaying such behaviour after the death of their owner, or monogamous animals refusing to feed after the death of their mate. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. Typically, there is also an internal digestive chamber with either one opening (in Ctenophora, Cnidaria, and flatworms) or two openings (in most bilaterians). [29][30] Animals have evolved numerous mechanisms for avoiding close inbreeding. Per biodiversità si intende l'insieme di tutte le forme viventi, geneticamente dissimili e degli ecosistemi ad esse correlati. [44][45][46] Animals living close to hydrothermal vents and cold seeps on the dark sea floor consume organic matter of archaea and bacteria produced in these locations through chemosynthesis (by oxidizing inorganic compounds, such as hydrogen sulfide). Oecologia Berlin 14:289–294, "Parasites brainwash grasshoppers into death dive", "Toxoplasma gondii-altered host behaviour: clues as to mechanism of action", "Fatal Attraction in Rats Infected with Toxoplasma gondii", snopes.com: White Wilderness Lemmings Suicide, https://en.wikipedia.org/w/index.php?title=Animal_suicide&oldid=977007307, Articles with dead external links from September 2019, Articles with permanently dead external links, Articles needing additional references from May 2020, All articles needing additional references, Articles with unsourced statements from May 2020, Creative Commons Attribution-ShareAlike License, This page was last edited on 6 September 2020, at 11:16. [57] Several animals are microscopic; some Myxozoa (obligate parasites within the Cnidaria) never grow larger than 20 µm,[58] and one of the smallest species (Myxobolus shekel) is no more than 8.5 µm when fully grown. Historically, Aristotle divided animals into those with blood and those without. The Bilateria include the protostomes—in which many groups of invertebrates are found, such as nematodes, arthropods, and molluscs—and the deuterostomes, containing both the echinoderms as well as the chordates, the latter containing the vertebrates. These two groups have long been considered close relatives because they share trochophore larvae. In carnivorous or omnivorous species, predation is a consumer-resource interaction where a predator feeds on another organism (called its prey). Major animal paintings include Albrecht Dürer's 1515 The Rhinoceros, and George Stubbs's c. 1762 horse portrait Whistlejacket. Their relationships are still disputed; the sister group to all other animals could be the Porifera or the Ctenophora, both of which lack hox genes, important in body plan development. From Middle English animal, from Old French animal, from Latin animal, a nominal use of an adjective from animale, neuter of animālis, from anima (“breath, spirit”). Two smaller phyla, the Onychophora and Tardigrada, are close relatives of the arthropods and share these traits. Blum, Geoffrey. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa (now synonymous for Animalia) and the Protozoa, single-celled organisms no longer considered animals. [93], These genes are found in the Placozoa[94][95] and the higher animals, the Bilateria. A wide variety of animals are kept as pets, from invertebrates such as tarantulas and octopuses, insects including praying mantises,[176] reptiles such as snakes and chameleons,[177] and birds including canaries, parakeets, and parrots[178] all finding a place. Questa pagina è stata modificata per l'ultima volta il 26 set 2020 alle 12:43. The digestive chamber has two openings, a mouth and an anus, and there is an internal body cavity, a coelom or pseudocoelom. [129][130], The Ecdysozoa are protostomes, named after their shared trait of ecdysis, growth by moulting. The kingdom Animalia includes humans but in colloquial use the term animal often refers only to non-human animals. These groups have a reduced coelom, called a pseudocoelom. 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