Any one of numerous species of large cartilaginous ganoid fishes belonging to Acipenser and allied genera of the family Acipenseridæ. They run up rivers to spawn, and are common on the coasts and in the large rivers and lakes of North America, Europe, and Asia. Caviar is prepared from the roe, and isinglass from the air bladder.
Sturgeon eggs, known commonly as caviar, are one of the world's most well recognized delicacies. Sturgeon live in rivers, coastal marine waters, and lakes in the Northern hemisphere and mature at a relatively late age, usually between 15 and 25 years, though they can live to be over 100 years old. Because of this late maturity, their populations are particularly vulnerable to overfishing. Because of declining natural populations, coupled with the continued popularity and profitability of caviar, sturgeon farming has gained more focus on the global scale.