meaning that the greater the force of the stream of water is the more likely the embryo migrates. Migration plays a big role in Kaluga's early life. The migration of the Kaluga is considered a passive migration because the embryos have no control over where the river flow takes them. However, when grown the Kaluga constantly migrates back and forth between upstream and downstream. The generation length of the species is not less than 20 years, comparable to humans. Life cycle Kaluga spends at least part of its life in salt water and returns to rivers to breed. The Kaluga Sturgeon spawns in lower reaches of the Amur River in strong-current habitats in the mainstream of the river on gravel or sandy-gravel bottom at water temperatures of 70 °F (12-20 °C) in depths of 6–10 feet (2–3 m). Spawning peaks from the end of May to July. Adults spawn many times during their life cycle. Spawning periodicity is 4–5 years in females and 3–4 years in males. Water temperature affects the onset of maturity of females. Females spawn a year earlier during warm years than they would during cold years. Population Kaluga sturgeon have declined sharply since the 1800s. Official catch records dropped from: 595 tons in 1881 61 tons in 1948 89 tons in 1996 This indicates an 85% decline in catches from 1881 to 1996. Since 2000, Kaluga sturgeon older than 10 years have not been observed in the Amur River channel during non-spawning periods, suggesting that adults in the Amur River are absent. Behavior Kaluga Sturgeon hatch in shallow gravel beds in the freshwater estuaries of the Amur River. Their parents play no role in their lives. They remain in the egg from 83 to 295 hours and hatch with a yolk sac that feeds them for up to 8 or 9 days. After that, the Kaluga Sturgeon are forced to hunt. They hunt for tiny zooplankton, insects, and shrimp. They reach the sea with the help of the current and remain there until they are ready to breed, between the ages of 10 and 14. Females are only able to breed every four years. Their spawning season begins in May and ends in July. Adult Kaluga Sturgeons travel in small groups of between 3 and 20 individuals to the shallow gravel beds to spawn. Sometimes if the Kaluga Sturgeon is too large it may die from