In the classical era, Aristotle divided animals,d based on his own observations, into those with blood (roughly, the vertebrates) and those without. The chordates are dominated by the vertebrates (animals with backbones), which consist of fishes, amphibians, reptiles, birds, and mammals. Most protostomes have schizocoelous development, where cells simply fill in the interior of the gastrula to form the mesoderm. Most appear to belong to two major lineages, the protostomes and the deuterostomes.
The characters 日本 mean ‘sun origin’, basswin which is the source of the popular Western epithet “Land of the Rising Sun”. Nihon is typically used in everyday speech and reflects shifts in Japanese phonology during the Edo period. Nippon, the original Sino-Japanese reading of the characters, is favored for official uses, including on Japanese banknotes and postage stamps. Before 日本 was adopted in the early 8th century, the country was known in China as Wa (倭, changed in Japan around 757 to 和) and in Japan by the endonym Yamato.
Having a front end means that this part of the body encounters stimuli, such as food, favouring cephalisation, the development of a head with sense organs and a mouth. The digestive chamber has two openings, a mouth and an anus, and in the Nephrozoa there is an internal body cavity, a coelom or pseudocoelom. Most members of Medusozoa, including jellyfish and most hydrozoans, have a polyp form as well, but also have a motile medusae stage. Members of the group Anthozoa, such as sea anemones, coral, and sea pens only are sessile polyps. Sponges lack the complex organisation found in most other animal phyla; their cells are differentiated, but in most cases not organised into distinct tissues, unlike all other animals.
The country attracted 36.9 million international tourists in 2024, and was ranked eleventh in the world in 2019 for inbound tourism. Other human rights issues include the treatment of marginalized groups, such as ethnic minorities, refugees and asylum seekers. However, it lacks any laws against discrimination based on race, ethnicity, religion, sexual orientation, or gender identity and does not have a national human rights institution. Japan’s constitution prohibits racial and religious discrimination, and the country is a signatory to numerous international human rights treaties. The military is governed by the Ministry of Defense, and primarily consists of the Japan Ground Self-Defense Force, the Japan Maritime Self-Defense Force, and the Japan Air Self-Defense Force. It spent 1.4% of its total GDP on its defense budget and maintained the tenth-largest military budget in the world in 2025.

Numbers and habitats of major phyla

• Japanese writing uses kanji (Chinese characters) and two sets of kana (syllabaries based on cursive script and radicals used by kanji), as well as the Latin alphabet and Arabic numerals.
• The main rainy season begins in early May in Okinawa, and the rain front gradually moves north.
• During the Meiji period (1868–1912), the Empire of Japan emerged as the most developed state in Asia and as an industrialized world power that pursued military conflict to expand its sphere of influence.
• The true aim of the reforms was to bring about greater centralization and to enhance the power of the imperial court, which was also based on the governmental structure of China.
• Oak Toad Oarfish Ocean Perch Ocean Pout Ocean Whitefish Oceanic Whitetip Shark Ocellated Turkey Ocelot Octopus Oenpelli python Oilfish Okapi Old English Sheepdog Old House Borer Oleander Hawk Moth Olingo Olive Baboon Olive python Olive Sea Snake Olm Olympic Marmot Onagadori Chicken Onager Opabinia Opah Opaleye (Rudderfish) Opossum Oranda Goldfish Orange Baboon Tarantula Orange Dream Ball Python Orange Roughy Orange Spider Orange Tanager (Orange-Headed Tanager) Orange-Crowned Warbler Orangutan Orb Weaver Orchard Oriole Orchid Dottyback Oregon Spotted Frog Ori-Pei Oribi Oriental Cockroach Oriental Dwarf Kingfisher Orinoco Crocodile Ornate Bichir Ornate Black-Tailed Rattlesnake Ornate Box Turtle Ornithocheirus Ornithomimus Ortolan Bunting Oscar Fish Osprey Ostracod Ostrich Otter Otterhound Ovenbird Oviraptor Owl Owl Butterfly Owlfly (Ascalaphidae) Ox Oxpecker Oyster Oyster Toadfish Ozark Bass
• The popular folk music, with the guitar-like shamisen, dates from the 16th century.

Animals that eat both plants and meat are called omnivores. Other animals eat only meat and are called carnivores. Some animals eat only plants; they are called herbivores. The animal mode of nutrition is called heterotrophic because they get their food from other living organisms. Also, the cells of animals have different cell membranes to other eukaryotes like plants and fungi.
For sexual reproduction, most sponges are hermaphrodites, they produce both egg and sperm cells. In addition to sponges, Placozoa has no symmetry and was often considered a “missing link” between protists and multicellular animals. Extant phyla in these rocks include molluscs, brachiopods, onychophorans, tardigrades, arthropods, echinoderms and hemichordates, along with numerous now-extinct forms such as the predatory Anomalocaris.

• Japanese animated films and television series, known as anime, were largely influenced by Japanese manga and have become highly popular globally.
• The deployment of troops to Iraq and Afghanistan marked the first overseas use of Japan’s military since World War II.
• Members of the group Anthozoa, such as sea anemones, coral, and sea pens only are sessile polyps.
• Major animal paintings include Albrecht Dürer’s 1515 The Rhinoceros, and George Stubbs’s c.
• The Porifera (sponges) have long been assumed to be sister to the rest of the animals, but there is evidence that the Ctenophora may be in that position.

Modern era

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. Other animals may have very specific feeding behaviours, such as hawksbill sea turtles which mainly eat sponges. In sponges, blastula larvae swim to a new location, attach to the seabed, and develop into a new sponge. Japan is the most successful Asian Rugby Union country and hosted the 2019 IRB Rugby World Cup. The country gained the hosting rights for the official Women’s Volleyball World Championship on five occasions, more than any other country.

Spinner Shark

For example, adult echinoderms are radially symmetric (unlike their larvae), while some parasitic worms have extremely simplified body structures. Many bilaterian phyla have primary larvae which swim with cilia and have an apical organ containing sensory cells. They also have a gut that extends through the basically cylindrical body from mouth to anus. Many bilaterians have a combination of circular muscles that constrict the body, making it longer, and an opposing set of longitudinal muscles, that shorten the body; these enable soft-bodied animals with a hydrostatic skeleton to move by peristalsis.

Bluetick Coonhound

The Ryukyu Islands, which include Okinawa, are a chain to the south of Kyushu. The country’s five main islands, from north to south, are Hokkaido, Honshu, Shikoku, Kyushu and Okinawa. On March 11, 2011, Japan suffered the Tōhoku earthquake—the largest by magnitude in its recorded history—which, along with the ensuing tsunami, triggered the Fukushima nuclear accident. The war cost Japan millions of lives and many of its conquered territories, including de jure parts of Japan such as Korea, Taiwan, Karafuto, and the Kurils.
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. The following table lists estimated numbers of described extant species for the major animal phyla, along with their principal habitats (terrestrial, fresh water, and marine), and free-living or parasitic ways of life. The blue whale (Balaenoptera musculus) is the largest animal that has ever lived, weighing up to 190 tonnes and measuring up to 33.6 metres (110 ft) long. Vertebrates such as the lobe-finned fish Tiktaalik started to move on to land in the late Devonian, about 375 million years ago. Some benthic animals living close to hydrothermal vents and cold seeps on the dark sea floor consume organic matter produced through chemosynthesis (via oxidising inorganic compounds such as hydrogen sulfide) by archaea and bacteria.
Japan is a unitary state and constitutional monarchy in which the power of the emperor (Tennō) is limited to a ceremonial role. As the host and signatory of the 1997 Kyoto Protocol, Japan is under treaty obligation to reduce its carbon dioxide emissions and to take other steps to curb climate change. Japan ranks 20th in the 2018 Environmental Performance Index, which measures a country’s commitment to environmental sustainability. The highest temperature ever measured in Japan, 41.8 °C (107.2 °F), was recorded on August 5, 2025. The main rainy season begins in early May in Okinawa, and the rain front gradually moves north.