This is an article about a fish 'ayu'. For a Japanese singer, see Ayumi Hamasaki. Ayu is her nickname. Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria Placozoa Subregnum Bilateria  Acoelomorpha  Orthonectida  Rhombozoa  Myxozoa  Superphylum Deuterostomia     Chordata (vertebrates, etc. ... Typical Classes Subphylum Urochordata - Tunicates Ascideiacea Thaliacea Larvacea Subphylum Cephalochordata - Lancelets Subphylum Myxini - Hagfishes Subphylum Vertebrata - Vertebrates Petromyzontida - Lampreys Placodermi (extinct) Chondrichthyes - Cartilaginous fishes Acanthodii (extinct) Actinopterygii - Ray-finned fishes Actinistia - Coelacanths Dipnoi - Lungfishes Amphibia - Amphibians Reptilia - Reptiles Aves - Birds Mammalia - Mammals Chordates (phylum Chordata) include the vertebrates, together with... Orders See text The Actinopterygii are the ray-finned fish. ... Families Suborder Argeninoidei   Superfamily Argentinoidea     Argentinidae (herring smelts)     Microstomatidae     Bathylagidae (deep-sea smelts)     Opisthoproctidae (barreleyes)   Superfamily Alepocephaloidea     Leptochilichthyidae     Alepocephalidae (slickheads)     Platytroctidae     (Searsiidae) Suborder Osmeroidei   Superfamily Osmeroidea     Osmeridae ( smelts)      Plecoglossidae (ayu fishes)     Salangidae (noodlefishes)     Sundasalangidae (Sundaland noodlefishes)   Superfamily Galaxoidea     Retropinnidae (New Zealand smelts)     Lepidogalaxiidae (salamanderfishes)     Galaxiidae Osmeriformes is an order of... In biology, binomial nomenclature is a standard convention used for naming species. ... Coenraad Jacob Temminck (March 31, 1778 - January 30, 1858) was a Dutch aristocrat and zoologist. ... Hermann Schlegel. ... 1846 was a common year starting on Thursday (see link for calendar). ... Ayumi Hamasaki as a covergirl for a Japanese teen magazine Popteen (Image © by http://www. ...

The ayu (Plecoglossus altivelis) is a amphidromous fish, the only species in its genus, Plecoglossus Temminck & Schlegel, 1846, and in family Plecoglossidae (order Osmeriformes). Native to the Palearctic ecozone, it occurs in rivers, lakes, and coastal waters of northern Hokkaido in Japan, the Korean Peninsula, China, and Taiwan. Many types of fish undertake migrations on a regular basis, on time scales ranging from daily to annual, and with distances ranging from a few meters to thousands of kilometers. ... Groups Conodonta Hyperoartia Petromyzontidae (lampreys) Pteraspidomorphi (early jawless fish) Thelodonti Anaspida Cephalaspidomorphi (early jawless fish) Galeaspida Pituriaspida Osteostraci Gnathostomata (jawed vertebrates) Placodermi Chondrichthyes (cartilaginous fish) Acanthodii Osteichthyes (bony fish) Actinopterygii (ray-finned fish) Sarcopterygii (lobe-finned fish) Actinistia (coelacanths) Dipnoi (lungfish) A fish is a poikilothermic (cold-blooded)* water-dwelling... In biology, a genus (plural genera) is a grouping in the classification of living organisms having one or more related and morphologically similar species. ... Coenraad Jacob Temminck (March 31, 1778 - January 30, 1858) was a Dutch aristocrat and zoologist. ... Hermann Schlegel. ... 1846 was a common year starting on Thursday (see link for calendar). ... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... Families Suborder Argeninoidei   Superfamily Argentinoidea     Argentinidae (herring smelts)     Microstomatidae     Bathylagidae (deep-sea smelts)     Opisthoproctidae (barreleyes)   Superfamily Alepocephaloidea     Leptochilichthyidae     Alepocephalidae (slickheads)     Platytroctidae     (Searsiidae) Suborder Osmeroidei   Superfamily Osmeroidea     Osmeridae ( smelts)      Plecoglossidae (ayu fishes)     Salangidae (noodlefishes)     Sundasalangidae (Sundaland noodlefishes)   Superfamily Galaxoidea     Retropinnidae (New Zealand smelts)     Lepidogalaxiidae (salamanderfishes)     Galaxiidae Osmeriformes is an order of... The Palearctic or Palaearctic is one of the eight ecozones dividing the Earth surface (see map). ... Ecozone is a classification system of the world first proposed by Miklos Udvardy under the name biogeographical realms for conservation purposes. ... Hokkaido   listen? (北海道 Hokkaidō, literal meaning: North Sea Route, Ainu: Mosir), formerly known as Ezo, is the second largest island of Japan. ...

Ayu on a Japanese postage stamp. The ayu has great cultural significance in Japan.

Omnivorous, the ayu feeds on algae, crustaceans, insects, sponges, and worms. The adults ascend from coastal waters into the lower reaches of rivers to spawn in the spring. The larvae descend to the sea immediately on hatching and winter there before returning to fresh water again in the spring. Most but not all individuals die after their first spawning. Japanese postage stamp showing ayu (Plecoglossus altivelis). ... Japanese postage stamp showing ayu (Plecoglossus altivelis). ... This 1974 stamp from Japan depicts a Class 8620 steam locomotive. ... Omnivores are organisms that consume both plants and animals. ... The algae (singular is alga) comprise several different groups of living things that produce energy through photosynthesis. ... Classes Class Branchiopoda Subclass Phyllopoda Subclass Sarsostraca Class Remipedia Order Enantiopoda Order Nectiopoda Class Cephalocarida Order Brachypoda Class Maxillopoda Subclass Mystacocarida Subclass Copepoda Subclass Branchiura Subclass Pentastomida Subclass Tantulocarida Subclass Thecostraca Infraclass Cirripedia Class Ostracoda Order Metacopina Subclass Myodocopa Subclass Podocopa Class Malacostraca Subclass Eumalacostraca Subclass Hoplocarida Subclass Phyllocarida The... Classes & Orders Subclass: Apterygota Orders Archaeognatha (Bristletails) Thysanura (Silverfish) Monura - extinct Subclass: Pterygota Orders Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Diaphanopteroidea - extinct Palaeodictyoptera - extinct Megasecoptera - extinct Archodonata - extinct Infraclass: Neoptera Orders Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Dermaptera (earwigs) Plecoptera (stoneflies) Orthoptera (grasshoppers, etc) Phasmatodea (walking sticks) Embioptera (webspinners) Zoraptera... Classes Calcarea Hexactinellida Demospongiae Sclerospongiae The sponges or poriferans (from Latin porus pore and ferre to bear) are animals of the phylum Porifera. ... WORM means Write Once, Read Many. ... A larva (Latin; plural larvae) is a juvenile form of animal with indirect development, undergoing metamorphosis (for example, insects or amphibians). ...

The flesh of the ayu has a distinctive, sweet flavour with "melon and cucumber aromas" (Gadsby). It is consequently highly prized as a food fish. Japanese anglers catch it with live lures as well as by a traditional method whereby captive cormorants catch the ayu and regurgitate the fish for human consumption (Akimichi). It is also fished commercially in large numbers, and captive juveniles are raised in aquaculture before being released into rivers for sport fishing. Fishing is the activity of hunting for fish. ... Genera Nannopterum Phalacrocorax Leucocarbo The Phalacrocoracidae family of birds is represented by over thirty species of cormorants and shags. ... Aquaculture is the cultivation of aquatic organisms, such as fish, shellfish, algae and other aquatic plants. ...

P. altivelis is also known as the sweetfish (for the sweetness of its flesh) or, in reference to its typical one-year life span, nen-gyo (year-fish).

Subspecies

The Ryukyu ayu-fish (P. altivelis ryukyuensis), is a subspecies of ayu, endemic to the Ryukyu Islands, which reaches a maximum total length of only about 14 cm (5.5 in). IUCN classifies the Ryukyu ayu-fish as Endangered on the basis of declining and highly fluctuating population and limited and declining range and habitat. In taxonomy, a subspecies is the taxon immediately subordinate to a species. ... Endemic, in a broad sense, can mean belonging or native to, characteristic of, or prevalent in a particular geography, race, field, area, or environment; Native to an area or scope. ... Location of Ryukyu Islands Flag of same The Ryukyu Islands (琉球列島 RyÅ«kyÅ«-rettō), also known as the Nansei-shoto (南西諸島 Nansei-shotō, which translates literally as the Southwest Islands), are an island chain stretching southwestward from the island of Kyushu in Japan. ... CM or cm may stand for: Cameroon (ISO country code) Roman numeral for 900 Chelmsford: CM is the British post code for the region in eastern England which is served by the Chelmsford postal sorting office. ... Mid-19th century tool for converting between different standards of the inch An inch is an Imperial and U.S. customary unit of length. ... The World Conservation Union or International Union for Conservation of Nature and Natural Resources (IUCN) is an international organization dedicated to natural resource conservation. ... The conservation status of a species is an indicator of the likelihood of that species continuing to survive. ...

References

• Akimichi, Tomoya. "Queen of Freshwater Streams". Kikkoman Soy Sauce Food Forum. Accessed on 21 December 2004.
• Gadsby, Patricia. "The Chemistry of Fish". Discover, November 2004, 50–57.
• "Plecoglossidae". FishBase. Ed. Ranier Froese and Daniel Pauly. October 2004 version. N.p.: FishBase, 2004.
• "Plecoglossus". FishBase. Ed. Ranier Froese and Daniel Pauly. October 2004 version. N.p.: FishBase, 2004.
• "Plecoglossus altivelis altivelis". FishBase. Ed. Ranier Froese and Daniel Pauly. October 2004 version. N.p.: FishBase, 2004.
• "Plecoglossus altivelis ryukyuensis". FishBase. Ed. Ranier Froese and Daniel Pauly. October 2004 version. N.p.: FishBase, 2004.
• "Plecoglossus altivelis" (TSN 162027). Integrated Taxonomic Information System. N.p.: Integrated Taxonomic Information System, 2004. Accessed on 20 December 2004.
• World Conservation Monitoring Centre. "Plecoglossus altivelis ssp. ryukyuensis" (ID 17595). 2004 IUCN Red List of Threatened Species. N.p.: IUCN, 2004.