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25-624: The upper reaches of the river in Yamanashi prefecture are also sometimes known as the Katsura River ( 桂川 , Katsuragawa ) , and the portion near the river mouth as the Banyu River ( 馬入川 , Banyugawa ) . The river overall was sometimes referred to as the Ayu River ( 鮎川 , Ayugawa ) from the sweetfish ( ayu ) which were once abundant in its waters. The Sagami River drains Lake Yamanaka ,

50-587: A backbone) such as blindworms and caecilians . Worms include several groups. The three main phyla are: Familiar worms include the earthworms , members of phylum Annelida . Other invertebrate groups may be called worms, especially colloquially. In particular, many unrelated insect larvae are called "worms", such as the railroad worm , woodworm , glowworm , bloodworm , butterworm , inchworm , mealworm , silkworm , and woolly bear worm . Worms may also be called helminths , particularly in medical terminology when referring to parasitic worms , especially

75-455: A long cylindrical tube-like body, no limbs , and usually no eyes . Worms vary in size from microscopic to over 1 metre (3.3 ft) in length for marine polychaete worms (bristle worms); 6.7 metres (22 ft) for the African giant earthworm, Microchaetus rappi ; and 58 metres (190 ft) for the marine nemertean worm (bootlace worm), Lineus longissimus . Various types of worm occupy

100-432: A more typical maximum size for the species is about 30 cm (1 ft). The form restricted to freshwater is considerably smaller than the amphidromous form. The freshwater-restricted ayu of Lake Biwa that migrate into their spawning streams in the spring can reach up to about 15 cm (6 in) in length, but those that migrate later in the year, primarily in the autumn, only grow to 10 cm (4 in). This

125-429: A small variety of parasitic niches, living inside the bodies of other animals. Free-living worm species do not live on land but instead live in marine or freshwater environments or underground by burrowing. In biology, "worm" refers to an obsolete taxon , Vermes , used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non- arthropod invertebrate animals , now seen to be paraphyletic . The name stems from

150-644: Is a living ayu placed on a hook, which swims when immersed into water. It provokes the territorial behavior of other ayu, which assault the "intruder" and get caught. Japanese fishers also catch it using cormorant fishing . On the Nagara River where Japanese cormorants ( Phalacrocorax capillatus ) are used by the fishermen, the fishing season draws visitors from all over the world. The Japanese cormorants, known in Japanese as umi-u (ウミウ, "sea-cormorant"), are domesticated birds trained for this purpose. The bird catches

175-511: Is caused by differences in the availability of food. Ayu is an edible fish, mostly consumed in East Asia . Its flesh has a distinctive, sweet flavour with "melon and cucumber aromas". It is consequently highly prized as a food fish. The main methods for obtaining ayu are by means of fly fishing , by using a fish trap , and by fishing with a decoy which is known as ayu-no-tomozuri in Japan. The decoy

200-651: Is not a worm at all, but a skin fungus. Lobopodians are an informal grouping of extinct panarthropods from the Cambrian to the Carboniferous that are often called worms or "worm-like animals" despite having had legs in the form of stubby lobopods. Likewise, the extant Onychophora are sometimes called velvet worms despite possessing stubby legs. Wyrm was the Old English term for carnivorous reptiles ("serpents") and mythical dragons . "Worm" has also been used as

225-459: Is sometimes used to refer to parasitic worms. The term is more commonly used in medicine , and usually refers to roundworms and tapeworms. In taxonomy, "worm" refers to an obsolete grouping, Vermes , used by Carl Linnaeus and Jean-Baptiste Lamarck for all non- arthropod invertebrate animals , now seen to be polyphyletic . In 1758, Linnaeus created the first hierarchical classification in his Systema Naturae . In his original scheme,

250-462: The Nematoda (roundworms) and Cestoda (tapeworms). Hence, " helminthology " is the study of parasitic worms. When a human or an animal, such as a dog or horse, is said to "have worms", it means that it is infested with parasitic worms , typically roundworms or tapeworms . Deworming is a method to kill off the worms that have infected a human or animal by giving anthelmintic drugs. " Ringworm "

275-411: The Old English word wyrm . Most animals called "worms" are invertebrates , but the term is also used for the amphibian caecilians and the slowworm Anguis , a legless burrowing lizard . Invertebrate animals commonly called "worms" include annelids , nematodes , flatworms , nemerteans , chaetognaths , priapulids , and insect larvae such as grubs and maggots . The term " helminth "

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300-545: The 13th century, worms were recognized in Europe as part of the category of reptiles that consisted of a miscellany of egg-laying creatures, including "snakes, various fantastic monsters, lizards, assorted amphibians", as recorded by Vincent of Beauvais in his Mirror of Nature . In everyday language, the term worm is also applied to various other living forms such as larvae , insects , millipedes , centipedes , shipworms (teredo worms), or even some vertebrates (creatures with

325-434: The 1990s. The name "sweetfish" was inspired by the sweetness of its flesh. In reference to its typical one-year lifespan, it is also written as 年魚 ("year-fish"). Some individuals live two to three years. The ayu is the prefectural fish of Gunma Prefecture and Gifu Prefecture . Two to three subspecies are recognized by some authors. Others do not distinguish the subtaxa. Subspecies include: An omnivore ,

350-544: The Sagami River, including the Miyagase Dam . Sweetfish The ayu sweetfish ( Plecoglossus altivelis ), ayu ( アユ, 鮎, 年魚, 香魚 ) or sweetfish , is a species of fish . It is the only species in the genus Plecoglossus and family Plecoglossidae. It is a relative of the smelts and other fish in the order Osmeriformes . Native to East Asia , it is distributed in the northwestern Pacific Ocean along

375-542: The animals were one of three kingdoms, divided into the classes of Vermes , Insecta , Pisces , Amphibia , Aves , and Mammalia . Since then the last four have all been subsumed into a single phylum, the Chordata , while his Insecta (which included the crustaceans and arachnids) and Vermes have been renamed or broken up. The process was begun in 1793 by Lamarck, who called the Vermes une espèce de chaos (a sort of chaos) and split

400-450: The autumn and move down to the lower part of rivers to breed. Some die after breeding and only live one year, but others return to live in the ocean and may spawn up to three times, each time moving into the lower part of rivers in the autumn. In Japan, some populations live their entire life in freshwater, only moving between lakes and the associated streams where they breed. These have a more variable migration pattern, moving upstream from

425-400: The autumn, laying their eggs in small pits they dig in the gravel. The eggs hatch shortly after and the larvae are carried downriver to the sea. They overwinter in coastal regions, staying there until the spring where the young fish typically are about 6 cm (2.5 in) long and move back to the rivers. Here they reach 15–30 cm (6–12 in) by the summer. They reach maturity by

450-400: The ayu feeds on algae , crustaceans , insects , sponges , and worms . It feeds on algae that accumulates on the rocks, scraping it off the rocks with their saw-shaped teeth. Adults typically maintain a feeding territory, but the form restricted to lakes and associated streams is schooling . Most populations of this species are amphidromous and breed in the lower part of rivers during

475-481: The ayu, stores it in its crop , and delivers it to the fishermen. Ayu is also fished commercially, and captive juveniles are raised in aquaculture before being released into rivers for sport fishing. A common method of preparing ayu and other small fish in Japan is to skewer it in such a way so that its body forms a wave, making it look as though it is swimming. Worm Worms are many different distantly related bilateral animals that typically have

500-576: The coast of Hokkaidō in Japan southward to the Korean Peninsula, China , Hong Kong and northern Vietnam . It is amphidromous , moving between coastal marine waters and freshwater lakes and rivers. A few landlocked populations also exist in lakes in Japan such as Biwa . Original wild populations in Taiwan became extinct in 1968 due to pollution and present extant populations were reintroduced from Japan in

525-442: The group into three new phyla, worms, echinoderms, and polyps (which contained corals and jellyfish). By 1809, in his Philosophie Zoologique , Lamarck had created 9 phyla apart from vertebrates (where he still had 4 phyla: mammals, birds, reptiles, and fish) and molluscs, namely cirripedes , annelids, crustaceans, arachnids, insects, worms, radiates , polyps, and infusorians . Chordates are remarkably wormlike by ancestry. In

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550-583: The growing need for a reliable supply of drinking and industrial water. Work on the Sagami Dam began in 1938; however, lack of funding and the advent of World War II delayed completion until after the end of the war. In the post war period, the Shiroyama Dam was also completed on the main stream of the Sagami River in 1965. A number of dams have also been completed on the Nakatsu River, the main tributary of

575-497: The lakes in the spring, summer or autumn. Although their larvae mostly stay within freshwater, some are carried downstream with the current to the sea and become part of the amphidromous populations. The freshwater-restricted populations typically reach an age of two or three years. During the breeding season the amphidromous and freshwater-restricted forms may occur together. Ayu are also stocked in reservoirs. Although there are reports of ayu up to 70 cm (2.3 ft) long,

600-772: The largest and easternmost of the Fuji Five Lakes in Yamanashi Prefecture. It loops northwest, then northeast through Yamanashi, before following a generally southerly course to exit into Sagami Bay of the Pacific Ocean between the cities of Hiratsuka and Chigasaki . It is dammed at several locations along the way, forming a number of reservoir lakes, the largest of which are Lake Sagami and Lake Tsukui . The river has had to re-cut its course several times due to repeated eruptions of Mount Fuji , and river terraces are in evidence along its upper reaches in Yamanashi. As

625-486: The river crosses Kanagawa, it forms natural levees in the soft soils of the alluvial plains of central Kanagawa's Sagamino plateau , and forms almost no river delta as it exits into the ocean. The potential of the upper reaches of the Sagami River for hydroelectric power development began to be developed in the 1930s, with the growth of industry and electrical consumption in the Yokohama - Kanagawa industrial belt, and

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