Green sturgeon

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Green sturgeon
Acipenser medirostris.jpg
CITES Appendix II (CITES) [2]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Acipenseriformes
Family: Acipenseridae
Genus: Acipenser
Species:
A. medirostris
Binomial name
Acipenser medirostris
Ayres, 1854
Synonyms [3] [4]
  • Acipenser acutirostrisAyres 1854 non Antipa 1909
  • Acipenser (Antaceus) agassiziiDuméril 1867
  • Acipenser (Antaceus) alexandriDuméril 1867
  • Acipenser (Antaceus) oligopeltisDuméril 1867

The green sturgeon (Acipenser medirostris) is a species of sturgeon native to the northern Pacific Ocean, from China and Russia to Canada and the United States.

Contents

Description

Green sturgeon Acipenser medirostris Head.jpg
Green sturgeon

Sturgeons are among the largest and most ancient of ray finned fishes. They are placed, along with paddlefishes and numerous fossil groups, in the infraclass Chondrostei, which also contains the ancestors of all other bony fishes. The sturgeons themselves are not ancestral to modern bony fishes but are a highly specialized and successful offshoot of ancestral chondrosteans, retaining such ancestral features as a heterocerca l tail, fin structure, jaw structure, and spiracle. They have replaced a bony skeleton with one of cartilage, and possess a few large bony plates instead of scales. Sturgeons are highly adapted for preying on bottom animals, which they detect with a row of sensitive barbels on the underside of their snouts. They protrude their very long and flexible “lips” to suck up food. Sturgeons are confined to temperate waters of the Northern Hemisphere. Of 25 extant species, only two live in California, the green sturgeon and the white sturgeon (A. transmontanus). (Moyle 2002)

Green sturgeon are similar in appearance to white sturgeon, except the barbels are closer to the mouth than to the tip of the long, narrow snout. The dorsal row of bony plates numbers 8–11, lateral rows, 23–30, and bottom rows, 7–10; there is one large scute behind the dorsal fin as well as behind the anal fin (both lacking in white sturgeon). The scutes also tend to be sharper and more pointed than in white sturgeon. The dorsal fin has 33–36 rays, the anal fin, 22–28. The body colour of the white sturgeon is yellow with some pink instead of the green of the green sturgeon.[ citation needed ]

Green sturgeon can reach 210 cm (7 feet) in length and weigh up to 160 kg (350 pounds).[ citation needed ] [5]

Protected status

On April 7, 2006, the National Marine Fisheries Service (NMFS) issued a final rule listing the Southern distinct population segment (DPS) of North American green sturgeon as a threatened species under the United States Endangered Species Act. Included in the listing is the green sturgeon population spawning in the Sacramento River and living in the Sacramento River, the Sacramento-San Joaquin Delta, and the San Francisco Bay Estuary. This threatened determination was based on the reduction of potential spawning habitat, the severe threats to the single remaining spawning population, the inability to alleviate these threats with the conservation measures in place, and the decrease in observed numbers of juvenile Southern DPS green sturgeon collected in the past two decades compared to those collected historically (NMFS 2006).

Critical habitat for the Southern DPS of green sturgeon was designated under the United States Endangered Species Act on October 9, 2009.

The northern DPS of the green sturgeon (which spawn in the Rogue River, Klamath River, and Umpqua River) is a U.S. National Marine Fisheries Service Species of Concern. Species of Concern are those species about which the U.S. Government's National Oceanic and Atmospheric Administration, National Marine Fisheries Service, has some concerns regarding status and threats, but for which insufficient information is available to indicate a need to list the species under the U.S. Endangered Species Act.

Life history and habitat requirements

A juvenile green sturgeon Night green sturgeon survey 2017-12-07 (44) (41011704120) (cropped).jpg
A juvenile green sturgeon

Sturgeons life history strategy seems organized around reducing risks. Sturgeons live a long time, delay maturation to large sizes, and spawn multiple times over their lifespan. The sturgeon's long life span and repeat spawning in multiple years allows them to outlive periodic droughts and environmental catastrophes. The high fecundity that comes with large size allows them to produce large numbers of offspring when suitable spawning conditions occur and to make up for years of poor conditions. Adult green sturgeon do not spawn every year, and only a fraction of the population enters freshwater where they risk greater exposure to catastrophic events. The widespread ocean distribution of green sturgeon ensures that most of the population is dispersed and less vulnerable than they are in estuaries and freshwater streams.

The ecology and life history of green sturgeon have received little study, evidently because of the generally low abundance, limited spawning distribution, and low commercial and sport fishing value of the species (Moyle 2002). Green sturgeon enters rivers mainly to spawn. and is more marine than other sturgeon species (Moyle 2002).

The United States Fish and Wildlife Service (USFWS) reported in 1995 that for the Klamath River, green sturgeon life history could be divided into three phases: 1) freshwater juveniles (< 3 years old); 2) coastal migrants (3–13 years old for females and 3–9 years for males); and 3) adults (>13 years old for females and > 9 years old for males).

Northern DPS green sturgeon migrate up the Klamath River between late February and late July (Moyle 2002). The spawning period is March–July, with a peak from mid-April to mid-June (Moyle 2002). Spawning takes place in deep, fast water (Moyle 2002). Preferred spawning substrate is likely large cobble, but it can range from clean sand to bedrock (Moyle 2002). Eggs are broadcast and externally fertilized in relatively fast water and probably in depths greater than 3 m (Moyle 2002). Female green sturgeon produce 59,000–242,000 eggs, about 4.34  mm (171 mils) in diameter (Van Eenennaam et al. 2001 and 2006).

Temperatures of 23–26 °C (73–79 °F) affected cleavage and gastrulation of green sturgeon embryos and all died before hatch (Van Eenennaam et al. 2005). Temperatures of 17.5–22 °C (63.5–71.6 °F) were suboptimal as an increasing number of green sturgeon embryos developed abnormally and hatching success decreased at 20.5–22 °C (68.9–71.6 °F), although the tolerance to these temperatures varied between progenies (Van Eenennaam et al. 2005). The lower temperature limit was not evident from the Van Eenennaam et al. 2005 study, although hatching rate decreased at 11 °C (52 °F) and hatched green sturgeon embryos were shorter, compared to 14 °C (57 °F). The mean total length of hatched green sturgeon embryos decreased with increasing temperature, although their wet and dry weight remained relatively constant (Van Eenennaam et al. 2005). Van Eenennaam et al. 2005 concluded that temperatures 17–18 °C (63–64 °F) may be the upper limit of the thermal optima for green sturgeon embryos. Growth studies on younger juvenile green sturgeon determined that cyclical 19–24 °C (66–75 °F) water temperature was optimal (Allen et al. 2006).

Green sturgeon fertilization and hatching rates are 41.2% and 28.0%, compared with 95.4% and 82.1% for the white sturgeon (Deng et al. 2002). However, the survival of green sturgeon larvae is very high (93.3%) (Deng et al. 2002). Female green sturgeon invest a greater amount of their reproductive resources into maternal yolk for nourishment of the embryo, which results in larger larvae (Van Eenennaam et al. 2001). Five-day-old green sturgeon larvae have almost twice the weight of white sturgeon larvae (65 milligrams or 1.00 grain versus 34 milligrams or 0.52 grains) (Van Eenennaam et al. 2001). This greater reserve of maternal yolk and larger larvae could provide an advantage in larval feeding and survival (Van Eenennaam et al. 2001). Compared with other acipenserids, green sturgeon larvae appear more robust and easier to rear (Van Eenennaam et al. 2001). Juveniles continue to grow rapidly, reaching 300 mm (12 in) in 1 year and over 600 mm (24 in) within 2–3 years for the Klamath River (USFWS 1995). Juveniles spend from 1–4 years in fresh and estuarine waters and disperse into salt water at lengths of 300–750 mm (12–30 in) (USFWS 1995).

A conceptual model of early behavior and migration of green sturgeon early life intervals based on the Kynard et al. 2005 study follows: Females deposit eggs at sites with large rocks and moderate or eddy water flow that keeps the large, dense, poorly adhesive eggs from drifting, so eggs sink deep within the rocks. CH2M Hill (2002) assumed that hatchling green sturgeon embryos drift downstream like hatchling white sturgeon embryos. This was incorrect. Hatchling green sturgeon embryos seek nearby cover, and remain under rocks, unlike white sturgeon which drift downstream as embryos (i.e. newly hatched green sturgeon do not exhibit pelagic behavior like newly hatched white sturgeon) (Deng et al. 2002). After about 9 days fish develop into larvae and initiate exogenous foraging up- and downstream on the bottom (they do not swim up into the water column, unlike white sturgeon). After a day or so, larvae initiate a downstream dispersion migration that lasts about 12 days (peak, 5 days). At the age of ten days, when exogenous foraging begins, green sturgeons are 19 to 29 mm (0.75 to 1.14 in) in length (mean 24 mm or 0.94 in) (Deng et al. 2002). At the age of 15 to 21 days, green sturgeon are 30 mm (1.2 in) or greater in length (Deng et al. 2002). At the age of 45 days, metamorphosis is complete and green sturgeon are 70 to 80 mm (3.1 in) in length (Deng et al. 2002). All migration and foraging during the migration period is nocturnal, unlike white sturgeon. During the first 10 months of life, green sturgeon are the most nocturnal of any North American sturgeon yet studied, and this was the case for all life intervals during any activity (migration, foraging, or wintering). Post-migrant larvae are benthic, foraging up- and downstream diurnally with a nocturnal activity peak. Foraging larvae select open habitat, not structure habitat, but continue to use cover in the day. When larvae develop into juveniles, there is no change in response to bright habitat, and no preference or avoidance of bright habitat. In the fall, juveniles migrate downstream mostly at night to wintering sites, ceasing migration at 7–8 °C (45–46 °F). During winter, juveniles select low light habitat, likely deep pools with some rock structure. Wintering juveniles forage actively at night between dusk and dawn and are inactive during the day, seeking the darkest available habitat.

For the Klamath River green sturgeon, an average length of 1.0 m (3 ft 3 in) is attained in 10 years, 1.5 m (4 ft 11 in) by age 15, and 2.0 m (6 ft 7 in) by 25 years of age (USFWS 1993). The largest reported green sturgeon weighed about 159 kg (351 lb) and was 2.1 m (6 ft 11 in) in length (USFWS 1993). The largest green sturgeon have been aged at 42 years, but this is probably an underestimate, and maximum ages of 60–70 years or more are likely (Moyle 2002).

Little is known about green sturgeon feeding at sea, but it is clear they behave quite differently than white sturgeon (CDFG 2005a). Green sturgeons are probably found in all open Oregon estuaries, with a lot of movement in and out of estuaries and up and down the coast (ODFW 2005a). Adults feed in estuaries during the summer (ODFW 2005a). Stomachs of green sturgeons caught in Suisun Bay contained Corophium sp. (amphipod), Crago franciscorum (bay shrimp), Neomysis awatchensis (Opossum shrimp) and annelid worms (Ganssle 1966). Stomachs of green sturgeon caught in San Pablo Bay contained Crago franciscorum (bay shrimp), Macoma sp. (clam), Photis californica (amphipod), Corophium sp. (amphipod), Synidotea laticauda (isopod), and unidentified crab and fish (Ganssle 1966). Stomachs of green sturgeons caught in Delta contained Corophium sp. (amphipod), Neomysis awatchensis (Opossum shrimp) (Radtke 1966). Radtke 1966 also reported that while the Asiatic clam (Corbicula fluminea) was abundant throughout the Delta, Suisun Bay and San Pablo Bay, it was not utilized as a food source by green sturgeons.

Conservation

Water diversion is one of the factors affecting conservation efforts for the green sturgeon.

Threats to the green sturgeon include being taken as bycatch in salmon gillnet and other fisheries, water development projects that affect migration or decrease habitat quality, and other land use stressors that affect habitat quality. Exotic species may negatively affect the southern DPS. Commercial fisheries have been prohibited in the Columbia River and Willapa Bay since 2001. Harvest of green sturgeon in California has been prohibited since March 2007. Beginning in March 2010 and to protect green sturgeon on their spawning grounds, the Sacramento River sturgeon fishery was closed year-round between the Keswick Dam and Hwy 162 bridge (approximately 90 miles or 140 km).[ citation needed ]

Current and historical distribution

The green sturgeon is the most widely distributed member of the sturgeon family Acipenseridae, and is also the most marine-oriented of the sturgeon species. Green sturgeon are known to range in nearshore marine waters from Mexico to the Bering Sea, with a general tendency to head North after their out-migration from freshwater (NMFS 2005). They are commonly observed in bays and estuaries along the western coast of North America, with particularly large concentrations entering the Columbia River estuary, Willapa Bay, and Grays Harbor during the late summer (Moyle 2002, NMFS 2005). While there is some bias associated with recovery of tagged fish through commercial fishing, the pattern of a northern migration is supported by the large concentration of green sturgeon in the Columbia River estuary, Willapa Bay, and Grays Harbor, which peaks in August (NMFS 2005).

Prehistoric fish distributions have been mapped by Gobalet et al. 2004 based on bones at Native American archaeological sites. Data were reported on dozens of sites throughout California and summarized by county. Sturgeon remains were observed in 12 counties, all in the Central Valley. Observations were concentrated at San Francisco Bay and Sacramento-San Joaquin and delta sites (Contra Costa, Alameda, San Francisco, Marin, Napa, San Mateo and Santa Cruz counties). Historical 18th-century accounts report the aboriginal gillnetting and use of tule balsa watercraft for the capture of sturgeon, and fishing weirs were also likely employed on bay tidal flats (Gobalet et al. 2004). Most sturgeons were unidentified species but green sturgeons were specifically identified from Contra Costa and Marin County sites. Sturgeon remains (unidentified species) were also identified from lower Sacramento River counties (Sacramento, Yolo, Colusa, Glenn, and Butte counties). No sturgeon remains were found in samples from the upper Sacramento River although other fish species including salmonids were reported in those areas.

Green sturgeons which spawn in the Rogue River, Klamath River, and Umpqua River are the Northern DPS green sturgeon, while the green sturgeons which spawn in the Sacramento River system are Southern DPS green sturgeon (NMFS 2005). Both the Northern DPS green sturgeon and Southern DPS green sturgeon occur in large numbers in the Columbia River estuary, Willapa Bay, and Grays Harbor, Washington (NMFS 2005).

A number of presumed spawning populations (Eel River and South Fork Trinity River) have been lost in the past 25–30 years (Moyle 2002). Moyle 1976 reported green sturgeon spawning in the Mad River, but does not mention the Mad River in 2002. Scott and Crossman 1973 reported potential spawning in the Fraser River in Canada, but Moyle 2002 reported that there was no evidence of green sturgeon spawning in Canada or Alaska. Green and white sturgeon enter the Feather River system annually and spawning of green sturgeon was documented for the first time in 2011(Seesholtz et al. 2014). No current use by sturgeon of Sacramento River tributaries, other than the Feather River system, has been reported (Beamesderfer et al. 2004, Moyle 2002). No evidence was found to indicate that green sturgeons were historically present, are currently present, or were historically present and have been extirpated from the San Joaquin River upstream from the Delta (Beamesderfer et al. 2004). There is no evidence of green sturgeon spawning in the Columbia River or other rivers in Washington (Moyle 2002, ODFW 2005a and 2005b). In contrast to those studies, samples from green sturgeon collected in the Columbia River suggest the existence of one or more spawning populations in addition to the Sacramento system, Klamath, and Rogue populations, suggesting not all spawning populations have been identified (Israel et al. 2004).

Individual Southern DPS green sturgeon tagged by the California Department of Fish and Game (CDFG) in the San Francisco Estuary have been recaptured off Santa Cruz, California; in Winchester Bay on the southern Oregon coast; at the mouth of the Columbia River; and in Gray's Harbor, Washington (USFWS 1993 and Moyle 2002). Most tags for Southern DPS green sturgeon tagged in the San Francisco Estuary have been returned from outside that estuary (Moyle 2002). Green sturgeons remain present in all documented historic habitats and ranges in Oregon (ODFW 2005b).

White and green sturgeon juveniles, subadults, and adults are widely distributed in the Sacramento-San Joaquin Delta and estuary areas including San Pablo (Beamesderfer et al. 2004). White sturgeon historically ranged into upper portions of the Sacramento system including the Pit River and a substantial number were trapped in and above Lake Shasta when Shasta Dam was closed in 1944 and successfully reproduced until the early 1960s (Beamesderfer et al. 2004). Landlocked white sturgeon populations have been widely observed in the Columbia and Fraser systems but no landlocked green sturgeon populations have ever been documented in any river system (Beamesderfer et al. 2004), indicating that green sturgeon likely did not historically spawn in the upper reaches of rivers prior to the construction of large dams as NMFS 2005 has assumed.

Taxonomy

According to recent genetic data, [6] the differences between the mitogenomes of the Green sturgeon (Acipenser medirostris) and the Sakhalin sturgeon (Acipenser mikadoi) to correspond to the variability at the intraspecific level. The time since the divergence of the Green sturgeon and the Sakhalin sturgeon may be approximately 160,000 years.

Related Research Articles

Sturgeon is the common name for the 28 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the Late Cretaceous, and are descended from other, earlier acipenseriform fish, which date back to the Early Jurassic period, some 174 to 201 million years ago. They are one of two living families of the Acipenseriformes alongside paddlefish (Polyodontidae). The family is grouped into four genera: Acipenser, Huso, Scaphirhynchus, and Pseudoscaphirhynchus. Two species may be extinct in the wild, and one may be entirely extinct. Sturgeons are native to subtropical, temperate and sub-Arctic rivers, lakes and coastlines of Eurasia and North America. A Maastrichtian-age fossil found in Morocco shows that they also once lived in Africa.

<span class="mw-page-title-main">Napa River</span> River in California, United States

The Napa River is a river approximately 55 miles (89 km) long in the U.S. state of California. It drains a famous wine-growing region called the Napa Valley, in the mountains north of the San Francisco Bay. Milliken Creek and Mt. Veeder watersheds are a few of its many tributaries. The river mouth is at Vallejo, where the intertidal zone of fresh and salt waters flow into the Carquinez Strait and the San Pablo Bay.

<span class="mw-page-title-main">Beluga (sturgeon)</span> Species of fish in the sturgeon family

The beluga, also known as the beluga sturgeon or great sturgeon, is a species of anadromous fish in the sturgeon family (Acipenseridae) of order Acipenseriformes. It is found primarily in the Caspian and Black Sea basins, and formerly in the Adriatic Sea. Based on maximum size, it is the third-most-massive living species of bony fish. Heavily fished for the female's valuable roe, known as beluga caviar, wild populations have been greatly reduced by overfishing and poaching, leading IUCN to classify the species as critically endangered.

<span class="mw-page-title-main">Kaluga (fish)</span> Species of fish

The kaluga, also known as the river beluga, is a large predatory sturgeon found in the Amur River basin. With a maximum size of at least 1,000 kg (2,205 lb) and 5.6 m (18.6 ft), the kaluga is one of the biggest of the sturgeon family. Like the slightly larger beluga, it spends part of its life in salt water. Unlike the beluga, this fish has 5 major rows of dermal scutes and feeds on salmon and other fish in the Amur. They have gray-green to black backs with a yellowish green-white underbelly.

The lake sturgeon, also known as the rock sturgeon, is a North American temperate freshwater fish, one of about 25 species of sturgeon. Like other sturgeons, this species is a bottom feeder and has a partly cartilaginous skeleton, an overall streamlined shape, and skin bearing rows of bony plates on the sides and back.

The Chinese sturgeon is a critically endangered member of the family Acipenseridae in the order Acipenseriformes. Historically, this anadromous fish was found in China, Japan, and the Korean Peninsula, but it has been extirpated from most regions due to habitat loss and overfishing.

<span class="mw-page-title-main">European sea sturgeon</span> Species of fish

The European sea sturgeon, also known as the Atlantic sturgeon or common sturgeon, is a species of sturgeon native to Europe. It was formerly abundant, being found in coastal habitats all over Europe. It is anadromous and breeds in rivers. It is currently a critically endangered species. Although the name Baltic sturgeon sometimes has been used, it has now been established that sturgeon of the Baltic region are A. oxyrinchus, a species otherwise restricted to the Atlantic coast of North America.

<span class="mw-page-title-main">Delta smelt</span> Species of fish

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.

<span class="mw-page-title-main">White sturgeon</span> Species of fish

White sturgeon is a species of sturgeon in the family Acipenseridae of the order Acipenseriformes. They are an anadromous (migratory) fish species ranging in the Eastern Pacific; from the Gulf of Alaska to Monterey, California. However, some are landlocked in the Columbia River Drainage, Montana, and Lake Shasta in California, with reported sightings in northern Baja California, Mexico.

<span class="mw-page-title-main">Atlantic sturgeon</span> Subspecies of fish

The Atlantic sturgeon is a member of the family Acipenseridae, and, along with other sturgeon, it is sometimes considered a living fossil. The Atlantic sturgeon is one of two subspecies of A. oxyrinchus, the other being the Gulf sturgeon. The main range of the Atlantic sturgeon is in eastern North America, extending from New Brunswick, Canada, to the eastern coast of Florida, United States. A disjunct population occurs in the Baltic region of Europe. The Atlantic sturgeon was in great abundance when the first European settlers came to North America, but has since declined due to overfishing, water pollution, and habitat impediments such as dams. It is considered threatened, endangered, and even locally extinct in many of its original habitats. The fish can reach 60 years of age, 15 ft (4.6 m) in length and over 800 lb (360 kg) in weight.

<span class="mw-page-title-main">Longfin smelt</span> Species of fish

The longfin smelt is a smelt that is found in several estuaries and lakes along the northern Pacific coast of North America.

<span class="mw-page-title-main">Pacific staghorn sculpin</span> Species of fish

The Pacific staghorn sculpin is a species of marine ray-finned fish belonging to the family Cottidae, the typical sculpins. This species is found in the eastern Pacific Ocean. It is the only species in the monospecific genus Lepidocottus.

<span class="mw-page-title-main">Shortnose sturgeon</span> Species of fish

The shortnose sturgeon is a small and endangered species of North American sturgeon. The earliest remains of the species are from the Late Cretaceous Period, over 70 million years ago. Shortnose sturgeons are long-lived and slow to sexually mature. Most sturgeons are anadromous bottom-feeders, which means they migrate upstream to spawn but spend most of their lives feeding in rivers, deltas and estuaries. The shortnose sturgeon is often mistaken as a juvenile Atlantic sturgeon because of its small size. Prior to 1973, U.S. commercial fishing records did not differentiate between the two species: both were reported as "common sturgeon", although it is believed based on sizes that the bulk of the catch was Atlantic sturgeon. The shortnose is distinguishable from the Atlantic sturgeon due to its shorter and rounder head.

<span class="mw-page-title-main">Gulf sturgeon</span> Subspecies of fish

The Gulf sturgeon is a subspecies of sturgeon that lives in the Gulf of Mexico and some rivers draining into it. The Gulf sturgeon was first recognized as a separate subspecies in 1955. The nominate subspecies is the Atlantic sturgeon, A. o. oxyrinchus. The Gulf sturgeon is listed as threatened under the United States Endangered Species Act, having been listed in 1991. Critical habitat, reflecting the range of the subspecies deemed essential for its continued survival, has been designated. The historical range is thought to have been from the Suwannee River on the western coast of Florida to the Mississippi River, and marine waters of the central and eastern portions of the Gulf of Mexico. Three sturgeon species in genus Scaphirhynchus share river territory with the Gulf sturgeon; none of the other sturgeon species is anadromous.

<span class="mw-page-title-main">Siberian sturgeon</span> Species of fish

The Siberian sturgeon is a species of sturgeon in the family Acipenseridae. It is most present in all of the major Siberian river basins that drain northward into the Kara, Laptev and East Siberian Seas, including the Ob, Yenisei Lena, and Kolyma Rivers. It is also found in Kazakhstan and China in the Irtysh River, a major tributary of the Ob. The species epithet honors the German Russian biologist Karl Ernst von Baer.

<span class="mw-page-title-main">Dabry's sturgeon</span> Species of fish

Dabry's sturgeon, also known as the Yangtze sturgeon, Chiangjiang sturgeon and river sturgeon, is a species of fish in the sturgeon family, Acipenseridae. It is endemic to China and today restricted to the Yangtze River basin, but was also recorded from the Yellow River basin in the past. It was a food fish of commercial importance. Its populations declined drastically, and since 1988, it was designated an endangered species on the Chinese Red List in Category I and commercial harvest was banned. It has been officially declared extinct in the wild by the IUCN as of July 21, 2022.

<span class="mw-page-title-main">Adriatic sturgeon</span> Species of fish

The Adriatic sturgeon is a species of fish in the family Acipenseridae. It is native to the Adriatic Sea and large rivers which flow in it of Albania, Greece, Italy, Montenegro, Croatia, Bosnia and Herzegovina and Slovenia. Specimens can be seen in several public aquarium, such the Milan Aquarium, Aquarium Finisterrae, Aquarium of the Po, and Oasis of Sant'Alessio in Lombardy.

<span class="mw-page-title-main">Bastard sturgeon</span> Species of fish

The bastard sturgeon, also known as the fringebarbel sturgeon, ship sturgeon, spiny sturgeon, or thorn sturgeon, is a species of fish in the family Acipenseridae. These fish are typically found along the benthos of shallower waters near shorelines or estuaries.

<i>Acipenser oxyrinchus</i> Species of fish

Acipenser oxyrinchus is a species of sturgeon.

<span class="mw-page-title-main">Ecology of the San Francisco Estuary</span>

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.

References

  1. Moser, M. (2022). "Acipenser medirostris". IUCN Red List of Threatened Species . 2022: e.T233A97433481. Retrieved 2 August 2022.
  2. "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  3. Froese, R.; Pauly, D. (2017). "Acipenseridae". FishBase version (02/2017). Retrieved 18 May 2017.
  4. Van Der Laan, Richard; Eschmeyer, William N.; Fricke, Ronald (11 November 2014). "Family-group names of Recent fishes". Zootaxa. 3882 (1): 1–230. doi: 10.11646/zootaxa.3882.1.1 . PMID   25543675.
  5. Dees, L. T. (1961). Sturgeons. U.S. Fish Wildlife Service. pp. 526:1–8.
  6. Shedko, Sergei (2017-05-04). "The Low Level of Differences between Mitogenomes of the Sakhalin Sturgeon Acipenser mikadoi Hilgendorf, 1892 and the Green Sturgeon A. medirostris Ayeres, 1854 (Acipenseridae) Indicates their Recent Divergence". Russian Journal of Marine Biology. 43 (2): 176–179. doi:10.1134/S1063074017020080. S2CID   35257523.

Further reading