Thanks Jay
Wow 6 years is a long time. Do they still live now? I heard they have long lifespan. Do you know what is their maximum lifespan?
Oh yes, they eat like a pig. Can you give me more info about fatty liver disease? The symptoms, cause, treatment, how to avoid etc?
Yes - we still have some. When I worked for another public aquarium, we had some that were over 10 years old.
Here is an excerpt from my upcoming fish disease book that discusses this malady:
Fatty liver disease
A major chronic health problem facing most long-term captive fishes is “fatty liver disease,” or liver degeneration. Fish do not assimilate fats well, so often, if a fish's diet is too high in fat, it will then be deposited in various tissues, especially the liver. Unlike with mammals, this fat is not readily usable during times of starvation. Even if food is withheld from a fat-laden fish, very little of the fat is ever reconverted into usable energy. Some fish do show outward signs of obesity, especially sedentary species such as groupers and lionfish. In these, fatty liver disease may only be diagnosed after death, when sections of the liver will show oil droplets and pieces of the liver itself will float in sea water. With many animals, a period of acute anorexia can cause liver damage.
Fatty liver disease is most common in adult fish whose growth rate has slowed considerably. Younger fish tend to grow fast enough to minimize fat deposition—excess calories are turned into muscle tissue instead. With long-term captive fish, fatty liver disease is the leading cause of (or contributor to) death. Virtually every lionfish held in captivity longer than three years will show evidence of fatty liver disease upon necropsy.
What techniques are available to solve this problem? Nothing can be done for a fish once fatty liver disease has become evident. Prevention is the only course of action an aquarist can take. Simply putting the fish on a "diet" may not work, in that this may result in increased aggression towards other fish in the aquarium. The best solution is to avoid feeding herbivores diets high in meat proteins and to train carnivores to feed on low-protein, low-fat diets such as squid or gelatin diet. Also, avoid feeding any saturated fats to fish. Overall dietary fat levels should be less than 16% in actively growing fish and less than 9% in adult fish.
Jay Hemdal
