Commercial catfish farms grow about $500 million worth of catfish each year. You are going to take over a fish farm in South Carolina the second week of this lab and start raising catfish. Before you borrow money to run your new fish farm it would be wise to actually learn something about the animal. You will have to make decisions about how to take care of the fish to keep them healthy without wasting money. This week's lab revolves around a series of experiments that will help you plan for business success. Of course you will also be learning something about biology.

Tank Experiments

Using tanks in a laboratory, you will work on understanding three aspects of fish biology:

Temperature

All animals have a range of temperatures that they can tolerate and a smaller range at which they prosper. You want to know when to worry about water temperatures interfering with the growth of your catfish.

Oxygen

Air-breathing animals don't often have to worry about the amount of oxygen in the air. It can be an issue on tall mountains and in poorly ventilated areas like caves but adequate oxygen is usually available. This is not the case in water. Three different factors can contribute to a decline in oxygen levels:

1. As water warms it loses oxygen to the atmosphere;
2. Fish and other aquatic animals use up oxygen in water through their respiration and;
3. Decay, whether it is dead organisms rotting, uneaten food or fish wastes, uses up oxygen.

When the oxygen level gets low in your ponds your fish will stop gaining weight, get sick, and die. You need to know how much oxygen is enough and when to be concerned about dropping oxygen levels.

Protein Consumption

You will be able to order custom made fish food. It will contain protein, fats and carbohydrates, all of which are needed for healthy fish. The most expensive part of the feed is the protein. You want to give your fish enough protein so they grow well but too much protein wastes money and increase the amount of waste the fish produce. Excess protein waste tends to use up oxygen in the water and makes your fish unhealthy.

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The rest of the prelab reading are pages from the Fish Farm Student Handbook.
Read them before you take the pre-lab quiz.

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