Acipenser oxyrinchus is a species of sturgeon.
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.
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.
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.
Sturgeon are an anadromous species that live solitarily or in small groups. They migrate upriver in the spring to spawn. Sturgeons tend to inhabit the shallow waters of coastal shelves, coastal and estuarine areas on soft bottom in the sea, and can live down to a depth of 160 ft (49 m). Adults are migratory while at sea and will make long migrations to coastal areas, while juveniles will stay in fresh or brackish water until they are between two and five years of age. However, many larvae and juveniles do start to migrate and disperse small distances from their spawning sites.
Sturgeons will migrate upriver to spawn. Sturgeons from the Gulf of Mexico will naturally exhibit spawning migration in the spring. Peak numbers have been observed in March and April, which is when the fish will migrate into the Suwannee River in Florida. Sturgeon will migrate downstream for twelve days, peaking within the first six days. Atlantic sturgeons only need to move a short distance to reach rearing areas. Early sturgeon migrants tend to be nocturnal while later migrants are diurnal. 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.
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. 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.
The primary foods of sturgeon while in freshwater areas include soft-bodied annelids, arthropods, aquatic insects, and globular mollusks. Adults that have emigrated from estuaries and into the sea will usually feed on epibenthic and hyperbenthic amphipods, grass shrimp, isopods, and worms. Most adult sturgeon will also feed on detritus and biofilm. Sturgeons are most generally known for feeding on crustaceans, worms, and molluscs.
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. Sturgeons may have dominance hierarchies with large fish being dominant when competing for limited foraging space.
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. NatureServe considers the species Vulnerable.
In 2012, the Atlantic sturgeon received protection under the Endangered Species Act.
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."
