Sturgeons

     Sturgeons have long lives and some live to over 50 years. They can grow to 4 meters in length and weigh over 200 kg. They feed on organisms of animal origin. The first food of larvae is zooplankton, then they feed on worms, crustaceans, and mollusks. Larger individuals can also feed on fish, but only a few species are considered predatory. The American paddlefish (Polyodon spathula Walbaum) is specialized for plankton feeding.
     Sexual maturation of sturgeons is very slow by comparison with modern teleost fishes. The first spawning of the female may not occur until 15 - 20 years of age, and the male 12 - 18 years.
     Spawning take place in that section of the river where the water is deep, the current is strong enough to prevent settling of suspended particles, and the bottom is covered with stones or gravels. The size of the eggs varies according to the species, but generally eggs are 2 - 4 mm in diameter, with numerous micropyles, and very sticky.

Technology for artificial spawning