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White Sturgeon fish identification, its habitats, characteristics, fishing methods.
White sturgeon is the largest freshwater fish in North America and is the third largest species of sturgeon, after the Beluga and the Kaluga. The white sturgeon can reach 1,800 lb (800 kg) in weight and up to 20.1 ft (6.1 m) in length, and live for over 100 years. Sturgeons are classified as a bony fish, but actually are more cartilaginous than bony, their internal bone structure being more like a shark’s. Sturgeon has changed very little since they first appeared, over 175 million years ago and thus have the appearance of a very ancient fish.
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The white sturgeon (Acipenser transmontanus), also known as the Pacific sturgeon, Oregon sturgeon, Columbia sturgeon, Sacramento sturgeon, and California white sturgeon, is a fish of the family Acipenseridae which lives along the west coast of North America from the Aleutian Islands to Central California, are found from Ensenada, Mexico to Cook Inlet, Alaska and in most estuaries along the Eastern Pacific coast from Alaska Bay to Monterey, California. Landlocked in Columbia River drainage in Montana and Arizona.
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Description
The white sturgeon is a primitive, bottom dwelling fish characterized by slender, long cylindrical body very large size with large head and mouth. It has four barbels, used for sensing food, located on the bottom (ventral) side of its head in front of its huge, wide and toothless mouth. It has no scales, but scutes that are actually large modified scales which serve as a type of armor or protection.
Distinguish Characteristics
- Dorsal fin soft rays: 44–48
- Anal fin soft rays: 28–31
- 11-14 dorsal scutes
- 2 rows of 4 to 8 bony plates on a midventral line between the anus and anal fin
- 38-48 lateral scutes
- 9-12 ventral scutes on each side
- Max length: 6.1 m
- Max weight: 816.0 kg
- Max age: 104 years
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White sturgeon have 11-14 scutes in front of their single dorsal fin, all anterior to the dorsal fin and no scutes behind the dorsal, 38-48 scutes on the lateral side, and 9-12 bottom (ventral) scutes on each side. Dorsal color is dark to light gray, pale olive, or gray-brown. The white sturgeon's ventral or bottom surface is clean white. The scutes are lighter than the body in color, and the fins are dusky to opaque gray.
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Habitats
White sturgeons rely on streams, rivers, and estuarine habitat as well as marine waters during their lifecycle. They live on the bottom of slow-moving rivers, bays, and estuarine areas, including the brackish water at the mouths of large rivers. The white sturgeon is a slow growing, late maturing anadromous fish. White sturgeon spawns in large rivers in the spring and summer months and remain in fresh water while young. Older juveniles and adults are commonly found in rivers, estuaries, and marine environments.
Young white sturgeon primarily feed on algae and aquatic insects while remaining in rivers and estuarine environments. White sturgeon individuals larger than 48.3 cm primarily feed on fishes; smaller ones feed mainly on chironomids, but also takes small crustaceans, other insects and mollusks, shellfish, crayfish, and on various aquatic invertebrates, clams, amphipods, and shrimp. Lampreys, primitive eel-like fish, smelt, shad are come into rivers to spawn at the same time as the white sturgeon, and are a popular food source at that time.
They are well-adapted to finding food drifting by with their excellent sense of smell and taste. A sturgeon's taste buds are located on the outside of its mouth. This, along with the barbels, allows it to see the food before sucking it up into its mouth. Sturgeon also has been known to move into shallow water to eat freshwater clams. During the spawning season, the white sturgeon moves to clean, fast-moving areas of rivers, such as just below rapids, with gravel or larger rocks along the bottom. Feeding ceases just before spawning.
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Spawning
White sturgeons reach maturity at age between 15 and 25 years, but could be between 5-14 years, depending on the gender of the fish and the temperature of the water. They are anadromous fish, spending most of its time in the sea, usually close to shore, and most commonly moves into estuaries of large rivers to spawn in the early spring, from May through June. In the late spring or early summer, they congregate in areas of rivers with a swift heavy current, large cobble, gravel rocky bottom, near rapids, and a water temperature of 58 °F to 66 °F (14 °C to 19 °C); no nest is built. White sturgeon can spawn multiple times during their life, and apparently spawn every 4-11 years as they grow and mature. Females can produce from 100,000 to several million eggs each with males releasing sperm. Female white sturgeon do not spawn every year, older fish produces more eggs in each spawning but spawn less often.
Adults apparently broadcast spawn in the water column and the fertilized eggs drift downstream with the current until they reach a suitable habitat, then they attach to the gravel at the bottom to hatch. The eggs are brown in color, around 0.5 in. (1.3 cm) long, with a tadpole-like appearance. It can take 4 days to 2 weeks to hatch, for the yolk sac to be absorbed, depending on water temperature. About a month after hatching, the sturgeon will have a full set of fins, rays, and scutes. As small juveniles, they feed on insects, small fish, and small crustaceans. White Sturgeon can live to be over 100 years old. They are slow growing fish, with growth is dependent on water temperature. They reach 6 feet long around 25 years of age.
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White sturgeon is an excellent food fish that is sold fresh, smoked or frozen. Worldwide, sturgeon commercial fisheries use sturgeon for meat and eggs, the eggs being most sought after. Caviar is considered a delicacy in many parts of Europe and North America. White sturgeon have been a very important fish, both commercially and for sporting purposes, recently became a popular target fishery in the Columbia River production, with its valuable roe for caviar, is the second only to the Soviet Union's production. The white sturgeon is also an important fish for Native American fishermen on the Columbia and Klamath rivers.
Some sturgeons are caught with hook and line gear or hoopnets from platforms along the shore. In the Columbia River, size restrictions make it very unlikely any fishers ever legally retain egg bearing fish. The fish caught legally by sport and commercial fishers are too small and not yet sexually mature enough to make harvesting for eggs worthwhile.
Bait used for sturgeon is mostly its natural prey including shad, anchovies, shrimp, and smelt. Sometimes cheese, anchovies, pickled squid, dog food, and cat food could be used as bait. A strong, 10–12 foot (3.1–3.7 m) long rod and heavy salt water reel spooled with 40–100 pound test fishing line is used for bank fishing. For boat fishing a smaller 6–7 foot (2 m) long rod is used. Anglers vary the amount of weight used depending on how heavy the current is, anywhere from 6 to 20 ounces (210–560 g). Often, an angler will use a 10–12 inch soft braided leader to connect the weight to the hook. When sturgeon first encounters the bait, they mouth it to taste and feel it before inhaling it whole.
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