It can take over a decade for green sturgeon to reach breeding maturity, and adults have infrequent reproductive success. Small sturgeon are better grown in cool temperatures 10-15 o C but as their size increases to about 3-4" (7.5 to 10cm) the fish can tolerate the lower oxygen levels of temperatures up to 22 o C. Temperatures over this slows down the food uptake of the sturgeon and can lead to metabolic overload most sturgeon will not eat once the temperature is over 26 o C.
Adults have long, narrow, shovel-like snouts with whisker-like sensory organs called barbels on the undersides, and toothless “vacuum cleaner” mouths with no teeth. They spawn only in Oregon's Rogue River and the Klamath and Sacramento river systems in California.
The diet of White Sturgeon varies considerably throughout the year.
Acipenseridae. Instead, they use their long, flexible "lips" (i.e., protrusible jaw) to suck up food from the bottom. You can eat sturgeon in many ways. In estuaries, they concentrate in deep areas with soft bottoms and move into intertidal areas to feed at high tides. The sturgeon's long life span and repeat spawning in multiple years allows them to outlive periodic droughts and environmental catastrophes. Six of the eight populations of sturgeons are listed as endangered or threatened: the green, shortnose, Gulf, pallid, Alabama and Kootenai River white. The green sturgeon spends the most time in saltwater of any of the three sturgeon species that live part of their lives in the ocean, spending the majority of their time in rive… NORTH AMERICAN GREEN STURGEON } Acipenser medirostris Identification Guide (PDF, 1 page) Green sturgeon were first described in San Francisco Bay in 1857. What do Sturgeon eat? THREATS: Sturgeons are imperiled by water withdrawals from rivers, dams blocking access to spawning habitat, habitat alteration, overfishing, poaching for caviar, pesticides, and pollutants. RANGE: Green sturgeon are found in the ocean from the Bering Sea, Alaska, as far south as Ensenada, Mexico; they frequent estuaries and bays from British Columbia, Canada, to Monterey Bay, California, and river mouths from the Skeena River, British Columbia, to the Sacramento River, California, but are only found significant distances inland in a handful of rivers in Oregon and California. Adults travel as far as 93 miles upstream to spawn in rivers and need good water quality and specific temperatures to spawn and hatch their eggs. These long-lived fish have rows of bony plates, called “scutes”, instead of scales for protection.
Sturgeons life history strategy seems organized around reducing risks.
DESCRIPTION: Green sturgeon are large with shark-like tails, sandpaper-textured skin, and five widely separated rows of bony plates called scutes.
The sturgeon has a shovel-like snout and vacuum cleaner-like mouth that it uses to siphon food from the river-bottom. HABITAT: A bottom-dwelling species, green sturgeon are mostly seen from inshore waters to 200 feet, primarily in the seawater and mixing zones of bays and estuaries.
Like most sturgeon, they are anadromous but tend to spend more time in the ocean than most species.
Sturgeons live a long time, delay maturation to large sizes, and spawn multiple times over their lifespan. In the spring one of the main food sources are eulachons, which enter the Fraser River on their spawning migration.
BREEDING: Green sturgeon spawn during late spring and early summer in the mainstem of large river systems, in relatively fast water flows and probably in deep holes greater than three meters. FEEDING: Opportunistic predators that eat a variety of prey according to availability, sturgeon generally feed on invertebrates like shrimp, crabs, worms, amphipods, and isopods. Sturgeon do not have teeth. 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. MIGRATION: Both juveniles and adults move extensively up and down the coast to take advantage of scattered food resources. During the winter months food sources are scarce.
They are generally olive green in color, with a stripe down each side. Several species provide caviar from eggs. Large sturgeon will eat fish, but mainly fish that are small, disabled, or dead. Sturgeon are modern relics of the ancient group of bony fishes, though their skeleton consists of mostly cartilage rather than bone. FAMILY: Sturgeon, any of about 29 species of fishes of the family Acipenseridae (subclass Chondrostei), native to temperate waters of the Northern Hemisphere. RANGE: Green sturgeon are found in the ocean from the Bering Sea, Alaska, as far south as Ensenada, Mexico; they frequent estuaries and bays from British Columbia, Canada, to Monterey Bay, California, and river mouths from the Skeena River, British Columbia, to the Sacramento River, California, but are only found significant distances inland in a handful of rivers in Oregon and California. LIFE CYCLE: After spawning, the adhesive eggs settle to the river bottom and attach to cobblestones, hatching around eight days later.
Adult g… POPULATION TREND: The southern population has been reduced to about 300 spawning fish annually, while the northern population has been extirpated from at least four former spawning rivers. It can be fried such as you would do chicken in thin strips, baked or smoked. Most species live in the ocean and ascend rivers to spawn in spring or summer; a few others are confined to fresh water. Larvae are less than an inch long. Green sturgeon life can be divided into three phases: freshwater juveniles (under three years old); coastal migrants (three to thirteen for females, three to nine for males); and adults (more than thirteen for females or nine for males).
Juveniles stay in freshwater for one to four years before heading for estuaries, where they remain for up to four to six years more, migrating considerable distances along the coast as they grow larger.