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Oregon sturgeon fishing!White Sturgeon Morphology and BiologyThere are 23 species of sturgeon worldwide, nine of which can be found in the US, and two of which are native to the Pacific Northwest-- the white sturgeon, Acipenser transmontanus, and green sturgeon, Acipenser medirostris. White sturgeon are the largest species of fish found in fresh water in North America. White sturgeon in the Columbia River may grow to 12 feet in length. White sturgeon have a cartilaginous (no bones) skeleton and notochord (primitive spinal chord like sharks and rays). Sturgeon are one of the most ancient species of fish, having diverged from the shark family during the Jurassic Period about 185 million years ago (before the peak time of the dinosaurs). Whereas many species of dinosaurs became extinct, sturgeon populations thrived (until only recently), and morphologically speaking, have remained stable over time. White sturgeon have 5 rows of cartilaginous scutes (pronounced skoots), one dorsal row (along the back), two lateral rows (along the sides), and two ventral rows (along the belly). The number and arrangement of scutes is diagnostic of white sturgeon as a species – all white sturgeon have 11-14 dorsal scutes, 36-48 lateral scutes, and 9-12 ventral scutes. A small percentage of white sturgeon (<3%) have seven rows of scutes with the extra rows located between the lateral and dorsal rows. Scutes, which are extremely sharp on young fish, offer juvenile sturgeon protection from predators (like birds and pike minnow) when they are small. White sturgeon have no scales. Their skin is leathery and covered with denticles, small conical projections that give the skin a rough, sand paper-like texture. White sturgeon have a retractable tube-like mouth, with four barbels (catfish whiskers) at the tip of their cartilaginous snout. The barbels have olfactory (smell) and taste buds, which are used to locate food items. Additionally there are electro-receptors at the tip of the snout. White sturgeon have very poor eyesight, and the relative position of the eyes indicates that vision is not the primary sense used to locate food. White sturgeon feed upstream, using the smell, taste and electro-receptors in their snouts to locate food items in the current. Sturgeon have no teeth and use their tube-like mouths to siphon (vacuum) whole food items off the bottom. White sturgeon are opportunistic feeders and will eat almost anything. However, they prefer fresh dead fishes (anchovies, herring, shad and smelt), crawfish, lamprey, clams, sandshrimp, and other freshwater and marine invertebrates. White sturgeon are diadromous, meaning they may spend a portion of their lives in marine (salt-water) environments. Like salmon, sturgeon are all born in fresh water rivers, however unlike salmon, sturgeon do not need to go to the ocean to complete their life cycle. White sturgeon grow about seven to 12 inches long in their first year of life. After that sturgeon grow about 4 inches per year until they are 3 feet in length, and about 3 inches per year thereafter until sexually mature. Average ages for Columbia River white sturgeon are approximately: 8 inches-1 year; 3 feet-8 years; 4 feet-12 years; 5 feet-17 years; 6 feet-23 years. Sturgeon over 10 feet in length are rare. A 9-½ foot white sturgeon found recently in the lower Columbia was determined to be 64 years old. The largest fish of modern times do not approach the size of fish observed in the late 1800's. Male sturgeon may mature at a length of 5 feet, females generally at 6 feet. Females live longer than male white sturgeon and grow larger. Unlike salmon, sturgeon do not die after spawning and may be reproductively viable for many years (twenty or more). A mature female sturgeon will lay from 100,000-several million eggs at a spawning and can reproduce every 2-11 years. Columbia River white sturgeon spawn in the 4-mile reach immediately below Bonneville Dam at water temperatures 48-62F during April-June. Discrete populations of white sturgeon reproduce (spawn) in the Columbia, Fraser and Sacramento rivers, but individuals from these populations become mixed throughout their range. White sturgeon tagged in the Columbia River have been recaptured in all major coastal areas from the Sacramento River to Puget Sound. More Sturgeon Information Page 1 - Page 2 - Page 3 - Sizing Chart
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