In these fish, the fat apparently hardens in the colder water, causing the fat-impregnated muscles to stiffen and the fish to become exhausted and lose movement.
Very interesting. There are at least three analogous conditions in humans. One is �subcutaneous fat necrosis of the newborn.� The second is chilblains of the thigh. The former occurs when newborns are exposed to cold temperatures, especially after stressful deliveries. Neonates have highly saturated fat, especially high in stearic and palmitic acids, and it is likely that these are denatured under these circumstances.
Chilblains are especially common in environments where the thighs are exposed to wet cold, e.g., Great Britain. (The condition is almost never seen in Alabama.) I once saw a very nice presentation on the topic in England. There, females who exercised horses in winter, wearing tight lycra pants to do so, got chilblains, whereas males who wore loose-fitting jodhpurs did not.
Sclerema neonatorum is a fortunately rare condition in newborns usually associated with serious underlying disease. It is usually fatal and shows crystallization of their highly saturated subcutaneous fat.
Has anyone observed the abdominal fat of any species of Tilapia to see if the fat shows signs of crystallization or necrosis? Anyone in academics who has access to Tilapia suffering cold stress and can take specimens from them might have an easy and highly publishable paper.
Lou
