When food enters the small intestine, bile travels through the common bile duct to reach the duodenum. Gallstones are hard deposits that form inside the gallbladder when there is too much bilirubin or cholesterol in the bile.
That said, there is a considerable consensus that all three major trout species (brook, brown and rainbow) begin to experience some level of stress at around 68Â°F (20Â°C), with that stress increasing rapidly as the temperature rises further.
This is why they grow to such large sizes in the lakes. The brown trout in the Finger Lakes and Lake Ontario experience a phenomenal growth rate. They are able to utilize the colder water and venture in to warmer water that rainbow and lake trout do not feed in. The New York State record brown trout weighed 33 lb. 2oz.