Hypomesus nipponensis | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Osmeriformes |
Family: | Osmeridae |
Genus: | Hypomesus |
Species: | H. nipponensis |
Binomial name | |
Hypomesus nipponensis McAllister, 1963 | |
Hypomesus nipponensis (Japanese smelt, in Japanese: wakasagi [2] ) is a commercial food fish native to the lakes and estuaries of northern Honshu and Hokkaido, Japan, Korea, and Sakhalin, Khabarovsk Krai, and Primorsky Krai, Russia. [1] It has been introduced in other locations, including the San Francisco Delta of the United States. It is raised in fisheries, and is very similar in appearance to the delta smelt (H. transpacificus).
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Phylogeny of the genus Hypomesus including H. chishimaensis under H. nipponensis. [3] [4] |
Hypomesus chishimaensis was described as being a new species in the lakes of Kunashir and Iturup in 1997 based on claimed morphological differences. After later studies failed to find these morphological differences, it regarded as an ecotype of H. nipponensis. A 2007 genetic analysis supported this classification, and recommended that H. chishimaensis not be given its own binomial designation. [3]
Native to the lakes and estuaries of Hokkaido, Japan and introduced to the lakes on Honshu and Kyushu, the Japanese wakasagi was introduced to California water reservoirs by the California Department of Fish and Game to provide more prey for stocked rainbow trout after failed attempts to introduce native delta smelt to three foothill reservoirs. [5] [6] At the time, the California-native delta smelt and the Japanese smelt were thought to be separated members of the same species, H. olidus . [7] In 1959 the CDFG imported 3.6 million fertilized eggs attached to palm fiber mats from a population in Suwa Lake, located east of Tokyo; many of these eggs were dead on arrival. The fiber mats were placed in streams feeding into six lakes and reservoirs that appeared to be ecologically suitable for the smelt. [nb 1] It was thought at the time that these reservoirs could be chemically treated to eradicate the fish if they were found to be undesirable. [8] In 1972 and 1973 about 77,000 fish from the Shastina Reservoir were moved to the Almanor Reservoir in Plumas County. All attempts to introduce the fish were successful, except the Dodge and Big Bear Reservoir introductions, [5] the latter of which may have been partially attributable to chemical treatments meant to eradicate stunted crappie and goldfish. [8]
Although a retrospective analysis of preserved delta smelt samples caught in 1972 and 1982 from the Delta region has shown that wakasagi had been invading the estuaries in undetected quantities since at least the early 1970s, wakasagi expansion from these original introduction sites southward was not tracked until several years later. [5] In 1994 they were detected at the State Water Project pumping plant for the first time, and by 1998 the fish could be found throughout the estuary including the Suisun and San Pablo Bays. [5] [7] [9]
Because the two species are very similar in morphology and life history, the wakasagi presents several potential threats to the endangered delta smelt. Besides direct competition for nutritional resources and the possibility that wakasagi may prey on the eggs and larvae of delta smelt, [5] hybridization could either dilute the species or cause population decline due to sterilizing effects. In fact, a few hybrids have been captured in the wild, although all of them were first generation crosses and no evidence of back-crossing has been found, which would suggest that the hybrids were not viable. Misidentification of the species is an additional concern, which could lead to inaccurate assessments critical to making policy decisions; however this problem may be mitigated if genetic markers are used for identification. [7]
In addition to its negative effects on the delta smelt, the wakasagi significantly reduced Kokanee fisheries, but helped increase growth rates of other salmon and trout fisheries. [10]
Smelts are a family of small fish, the Osmeridae, found in the North Atlantic and North Pacific oceans, as well as rivers, streams and lakes in Europe, North America and Northeast Asia. They are also known as freshwater smelts or typical smelts to distinguish them from the related Argentinidae, Bathylagidae, and Retropinnidae.
The Sacramento perch is an endangered sunfish native to the Sacramento–San Joaquin River Delta, Pajaro, and Salinas River areas in California, but widely introduced throughout the western United States.
Pink salmon or humpback salmon is a species of euryhaline ray-finned fish in the family Salmonidae. It is the type species of the genus Oncorhynchus, and is the smallest and most abundant of the seven officially recognized species of salmon. The species' scientific name is based on the Russian common name for this species gorbúša (горбуша), which literally means humpie.
Hachirōgata or Hachirō Lagoon is a lake in Akita Prefecture in northern Japan. Its formal name is Lake Hachirō, but it is also called Hachirōgata Regulating Pond. At 4 meters below sea level, Hachirōgata is the lowest natural point in Japan.
The delta smelt is an endangered slender-bodied smelt, about 5 to 7 cm long, in the family Osmeridae. Endemic to the upper Sacramento-San Joaquin Estuary of California, it mainly inhabits the freshwater-saltwater mixing zone of the estuary, except during its spawning season, when it migrates upstream to fresh water following winter "first flush" flow events. It functions as an indicator species for the overall health of the Delta's ecosystem.
Hypomesus is a genus of smelts (Osmeridae), consisting of five species found in the northern hemisphere.
The longfin smelt is a smelt that is found in several estuaries and lakes along the northern Pacific coast of North America.
San Leandro Creek is a 21.7-mile-long (34.9 km) year-round natural stream in the hills above Oakland in Alameda County and Contra Costa County of the East Bay in northern California.
The green sturgeon is a species of sturgeon native to the northern Pacific Ocean, from China and Russia to Canada and the United States.
The San Francisco Estuary together with the Sacramento–San Joaquin River Delta represents a highly altered ecosystem. The region has been heavily re-engineered to accommodate the needs of water delivery, shipping, agriculture, and most recently, suburban development. These needs have wrought direct changes in the movement of water and the nature of the landscape, and indirect changes from the introduction of non-native species. New species have altered the architecture of the food web as surely as levees have altered the landscape of islands and channels that form the complex system known as the Delta.
Lake Abashiri is a meromictic lake in Abashiri, Hokkaidō, Japan. It is located in Abashiri Quasi-National Park. The Abashiri and Memanbetsu Rivers flow into the lake. Water exits the lake through the Abashiri River again and flows 7 kilometres (4.3 mi) to the Sea of Okhotsk.
Freshwater smelt may refer to:
Japanese smelt may refer to:
Hypomesus pretiosus, or surf smelt, is a marine smelt with a range from Prince William Sound, Alaska to Long Beach, California, although its population declines south of San Francisco. The surf smelt grows to be about 10 inches in southern waters, and 83⁄4 inches in northern waters near Canada. On average, surf smelt weigh about 10 to the pound.
Marsh Creek is a stream in east Contra Costa County, California in Northern California which rises on the eastern side of Mount Diablo and flows 30 miles (48 km) to the Sacramento–San Joaquin River Delta at Oakley, California, near Big Break Regional Shoreline. The creek flows through Marsh Creek State Park (California), where water is impounded to form Marsh Creek Reservoir, then through the city of Brentwood, California.
Searsville Dam is a masonry dam in San Mateo County, California, that was completed in 1892, one year after the founding of Stanford University, and impounds Corte Madera Creek to form a reservoir known as Searsville Reservoir or Searsville Lake. Searsville Dam is located in the Jasper Ridge Biological Preserve and is owned and operated by Stanford University. Neighboring cities include Woodside and Portola Valley, California.
Corte Madera Creek is a 7.3-mile-long (11.7 km) creek that flows north-northwest to Searsville Dam and then joins with Bear Creek to form San Francisquito Creek in California.
The Tridentiger bifasciatus is found in fresh and brackish waters. However, it is most abundant in low-salinity environments. The fish has typical features consistent with the family Gobiidae and grows to a maximum of 12 centimeters. These characteristics include two pelvic fins united from a conical sucking disk, a spiny anterior and a soft posterior dorsal fin, and eyes near the top of the head. These fins typically have 6-7 spines and 11-14 rays with orange tints on the edges. The Tridentiger bifasciatus has a flat wide head and is highly variable in color, but generally light or dark brown with midlateral spots and miniscule white spots on the head.
Peter B. Moyle is Distinguished Professor Emeritus in the Department of Wildlife, Fish and Conservation Biology and associate director of the Center for Watershed Sciences at the University of California, Davis. He has studied the ecology and conservation of fishes in freshwater and estuarine habitats in California (US) for over fifty years. He has a special interest in salmonid fishes and in the state's highly endemic freshwater and estuarine fish fauna. Moyle has authored or co-authored more than 270 peer-reviewed publications, including 10 books, and over 225 other publications, including ca. 75 blogs.
Coreoperca kawamebari, commonly known as the Japanese perch, redfin perch, Japanese river perch, eye-spot perch, fire tiger or in Anglophone parts of Japan, simply the perch, is a predatory species of the freshwater perch native to Japan and southern Korea. They are sometimes kept as pets. The Japanese perch are a member of the perch family but with the predatory feeding behaviour of the black bass and bluegill.