Acipenser oxyrinchus

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Acipenser oxyrinchus
A. o. oxyrinchus
CITES Appendix II (CITES)[2]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Acipenseriformes
Family: Acipenseridae
Genus: Acipenser
Species:
A. oxyrinchus
Binomial name
Acipenser oxyrinchus
Subspecies
  • Acipenser oxyrinchus desotoi
     Vladykov 1955
  • Acipenser oxyrinchus oxyrinchus
     Mitchill 1815
Synonyms[3][4]
  • Sturio accipenser Strøm 1784
  • Acipenser lichtensteinii Bloch & Schneider 1801
  • Acipenser (Antaceus) lecontei Duméril 1867
  • Acipenser (Antaceus) hallowellii Duméril 1870
  • Acipenser (Huso) kennicottii Duméril 1870
  • Acipenser (Huso) girardi Duméril 1870
  • Acipenser (Huso) macrorhinus Duméril 1870
  • Acipenser (Huso) bairdii Duméril 1870
  • Acipenser (Huso) holbrookii Duméril 1870
  • Accipenser ruthenus major Schöpf 1788
  • Acipenser (Huso) mitchillii Duméril 1870
  • Acipenser (Huso) storeri Duméril 1870
  • Acipenser oxyrhynchus (lapsus)

Acipenser oxyrinchus is a species of sturgeon.

Information

Acipenser oxyrinchus is a species with two subspecies:

Their main diet includes crustaceans, worms, and molluscs. This species is also known to migrate up the river when it is spawning.

IUCN.[6] They can be found in temperate and subtropical climates and in marine or freshwater environments.[3]

Characteristics

Acipenser oxyrinchus can grow to a length of 14 ft (4.3 m) and a weight of 800 lb (360 kg). The lifespan of this species can be around 60 years. The color of Acipenser oxyrinchus is bluish-black or olive brown with lighter sides and a white belly.

Behavior

Sturgeon are an

larvae and juveniles do start to migrate and disperse small distances from their spawning sites.[3]

Migration

Sturgeons will migrate upriver to

nocturnal while later migrants are diurnal.[8] During summer months, sturgeon will remain in localized bottom areas of the rivers. In the late fall, the sturgeon migrate out of spawning rivers and into the Gulf of Mexico.[7]

For all populations and subspecies of sturgeon, there are spawning migrations into

freshwater in early spring and movement into salt water in the fall. Timing and the unusual migratory behavior of sturgeon is a result of temporal water temperature changes.[7] Studies have also shown that amongst sturgeon in Gulf of Mexico and Suwannee River in Florida, fish gained 20% of their body weight while in Gulf of Mexico and lost 12% of their body weight during their time in the river.[9]

Spawning

The maximum level of survival for eggs, embryos, and larvae is at 15 to 20 °C (59 to 68 °F). Studies have shown that high mortalities are seen at temperatures of 25 °C (77 °F) or higher.[7] In order for spawning to occur, water temperature should be above 17 °C (63 °F). Spawning normally lasts between nine and twenty-three days, but can continue past this as long as the water temperature remains below 22 °C (72 °F).[10]

Free sturgeon

embryos (the first interval of sturgeon after hatching) hide under rocks and do not migrate. They are found in the freshwater spawning areas. Larvae and some juveniles start to migrate slowly for about five months downstream. This leads to a wide dispersal of the fish.[11] Typically, the entire freshwater reach of the river downstream from the actual spawning site is so filled with larva-juvenile individuals that it is considered to be a nursery habitat.[11]

Sturgeon populations will use the same spawning reefs from year to year. Habitat factors that can help determine spawning sites include the presence of gravel substrate, presence of eddy fields, slightly basic

calcium ion content. Eggs are usually deposited in a small area and scatter very little. It is not until larvae and juveniles start to migrate that the fish disperse widely.[10]

Body color

Some evidence has shown that developmental body color is related to migration style. Free embryos are light and are non-migratory, while migratory larvae and adults are dark. This is found to be consistent among many Acipenser species. The reason for this is unclear, but it may be adaptive to migration behavior and camouflage.[11]

Diet

The primary foods of sturgeon while in freshwater areas include soft-bodied

isopods, and worms. Most adult sturgeon will also feed on detritus and biofilm.[12] Sturgeons are most generally known for feeding on crustaceans, worms, and molluscs.[13]

Larvae-juvenile feeding was at the bottom, benthic foraging. However, food in the benthic zone is scarce, so many adapt drift feeding, in which they have holding positions in the water column and wait for food.[11] Sturgeons may have dominance hierarchies with large fish being dominant when competing for limited foraging space.[8]

Habitat

Sturgeons are widely distributed along the Atlantic coast of the United States. Their wide distribution and tendency to disperse has led to numerous subpopulations of sturgeon.[13]

In general, sturgeons usually inhabit primarily the temperate waters of the northern hemisphere. Gulf of Mexico sturgeons are probably adapted to warmer water temperatures. Due to sturgeons' predilection for cooler waters, when water temperatures rise too high, sturgeon will try to find cool spring waters which serve as thermal refuges until temperatures drop again.[7]

Susceptibility to anthropogenic disturbances

There are many wide-ranging subspecies along the Atlantic Coast of North America. Identification of

Endangered Species Act.[14]

The sturgeon's characteristics and life history make it susceptible to anthropogenic disturbances and make population restoration particularly difficult. They have late sexual maturity, only moderate fecundity, and spawn at low frequencies. Females spawn once every three to five years, and males every one to five years. This is due to their ability to live for an extremely long time (various sub-species can have a lifespan ranging from ten years to sixty years).[14]

The population of Atlantic sturgeons has decreased dramatically due to

overharvesting. The late 19th century saw a surge in demand for caviar, which led to overfishing of the Atlantic sturgeon. Today, only 22 out of its 38 original spawning rivers still have viable populations of the species.[15] They are particularly susceptible to bycatch mortality due to the many fisheries that exist within their natal estuaries. Their habitat range, which usually includes coastal spawning sites and coastal migrations, makes sturgeon well within contact of coastal fisheries.[14]

Effects of hypoxia

Hypoxia combined with high water temperatures in the summer has been shown to be consistent with decreased survival rates of young of the year sturgeon in Chesapeake Bay.[16]

Hypoxia is defined as low ambient oxygen levels, which may be very harmful to organisms living in the hypoxic body of water. Often, lower regions of the water column will be more hypoxic than upper levels, closer to the surface. When surface access is denied, the situation is lethal to sturgeon. Increased incidences of summertime hypoxia have led, in part, to degradation of many sturgeon nursery habitats in the United States.[16]

Conservation

Populations have declined dramatically over the last centuries, and even became extinct in Baltic range states in the later 20th century. Channelisation and barriers were part of the causes for declines affecting migration, along with pollution. Since 1996 Baltic sturgeon recovery has been attempted, with American donor populations used due to genetic similarities. Re-introduction with focus on returning these sturgeon to their native spawning grounds.[17] NatureServe considers the species Vulnerable.[18]

In 2012, the Atlantic sturgeon received protection under the Endangered Species Act.[19]

In 2022, the International Union for the Conservation of Nature noted that sturgeon was "the animal group most at risk of extinction in the world."[15]

References

  1. doi:10.2305/IUCN.UK.2022-1.RLTS.T245A2785934.en
    . Retrieved 15 April 2023.
  2. ^ "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  3. ^ a b c d Froese, Rainer; Pauly, Daniel (eds.) (2006). "Acipenser oxyrinchus" in FishBase. April 2006 version.
  4. ^ "Acipenseridae" (PDF). Deeplyfish- fishes of the world. Archived from the original (PDF) on 18 September 2017. Retrieved 18 May 2017.
  5. ^ "Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus)". NOAA Fisheries. Retrieved 24 February 2013.
  6. doi:10.2305/IUCN.UK.2022-1.RLTS.T182572773A182572813.en
    . Retrieved 26 November 2023.
  7. ^
    S2CID 36638570
    .
  8. ^
    S2CID 23950901
    .
  9. doi:10.1111/j.1600-0633.1996.tb00130.x
    .
  10. ^
    doi:10.1111/j.1439-0426.1999.tb00220.x
    .
  11. ^
    S2CID 34082533
    .
  12. doi:10.1577/1548-8659(1993)122<0378:fotgsi>2.3.co;2
    .
  13. ^ a b "Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus)". NOAA Fisheries Office of Protected Resources. Retrieved 24 October 2013.
  14. ^
    S2CID 25059194
    .
  15. ^
    ISSN 0362-4331
    . Retrieved 2023-02-06.
  16. ^ a b Secor, David H.; Troy E. Gunderson (1998). "Effects of hypoxia and temperature on survival, growth, and respiration of juvenile Atlantic sturgeon, Acipenser oxyrinchus" (PDF). Fishery Bulletin. Vol. 96, no. 3. pp. 603–613. Archived from the original (PDF) on 2013-10-29. Retrieved 24 October 2013.
  17. ^ Gessner, Jörn; Arndt, Gerd-Michael; Kapusta, Andrzej; Shibayev, Sergey; Gushin, Alexey; Pilinkovskij, Andrej; Povliūnas, Justas; Medne, Ruta; Purvina, Santa; Tambets, Meelis; Møller, Peter Rask (2019). Gessner, Jörn (ed.). "HELCOM Action Plan for the protection and recovery of Baltic sturgeon Acipenser oxyrinchus oxyrinchus in the Baltic Sea area" (PDF). Baltic Sea Environment Proceedings. 168.
  18. ^ "NatureServe Explorer 2.0". explorer.natureserve.org. Retrieved 5 April 2022.
  19. ^ Eilperin, Juliet (February 1, 2012). "Atlantic sturgeon listed as endangered species". The Washington Post.

External links

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