Tilapia Disease Symptom:
Loss of Appetite

There are several types of circumstances to consider if the only behavioral change found is loss of appetite. These include:

1. A loss of the palatability as would occur if the feed got wet and mouldy.

2. An early sign of a nutritional deficiency (e.g. prolonged exposure to a feed lacking in one of the essential nutrients).

3. An early warning of a water quality problem.

4. If the tilapia population has been chronically overfed.

HAMES advises you to:

1. Inspect the feed to see if it appears wet, mouldy or otherwise seems to be deteriorated. If the feed is abnormal it should be replaced with fresh feed and the fish population observed for a change in appetite.

2. Anorexia* (diminished or absence of appetite) is an early sign of essential nutrient deficiency for most fish. Tilapia usually feed on benthic algae and phytoplankton, thus micronutrient deficiency is extremely uncommon. If you suspect nutritional deficiency may be the reason your tilapia are not eating, contact your extension agent for advice on how to proceed.

3. Tilapia exposed to declining water quality or marginal environmental conditions may display loss of appetite as an early sign of distress. The water quality factors to consider include: dissolved oxygen, pH, temperature, ammonia, nitrite, chlorine and hydrogen sulfide. For additional assistance from HAMES, please proceed to the Water Analysis section or contact your extension agent.

4. If you suspect that the tilapia population may have been overfed, reduce the feed applied by 20% and assess the feeding response the following day. If the appetite does not show an increase, then overfeeding is probably not a factor.

Water temperature outside the ideal range can also result in a loss of appetite. +