Food Intake and Weight Gain in Fish
Aim: Through this experiment it is hoped that the results will shed light on how much the frequency of when the fish is fed can affect weight gain in the fish.
Hypothesis: Multiple predictions have been made, these include:
a. By increasing or decreasing the frequency of which the fish is fed, it is predicted that the fish’s weight will change accordingly.
b. It is predicted that the fish fed twice as often as the control fish will stop eating when full and gain similar weight to the control. The fish fed half as often will lose weight.
c. It is predicted that the fish fed half as often in comparison to the control will have minimal, but steady weight gain and the fish fed twice as often will eat all the food given and gain twice as much.
d. It is predicted that the fish fed twice as often will eat once a day and not eat the second, and gain the same amount of weight as the control. The fish fed half as often will have an unsteady weight gain. (lose/gain weight or have large differences in how much weight is gained)
e. All fish will die to unrelated causes e.g. Shock or exposure to chemicals/outside objects.
Equipment- 9 x Fantail Goldfish, 9 x separate containers/tanks (same size), 1 x small fish net with handle, 1 x container of Aqua One Goldfish Flakes, 1 x accurate scale, 1 x bottle of Aqua One Water Conditioner, pH paper (this wasn’t used in the experiment but if used, it could provide more accurate results), 1 x separate container to treat water in, 1 x charcoal filter, 1 x filter engine.
1. Fill a large container with 6L of water
2. Using the instructions of Aqua One Water Conditioner, 1mL: 12L. Therefore 6L of water should be treated with ½ mL. Stir well.
3. They were left in the original tank water and kept in a bag. That bag was placed in the treated water to allow the fish to adjust to the water temp.
4. The fish were removed from the treated water.
5. The 6L of treated water was separated evenly between the 9 containers/tanks.
6. The containers were labelled: (see diagram A)
Fish 1 Test 1, Fish 1 Test 2, Fish 1 Test 3
Fish 2 Test 1, Fish 2 Test 2, Fish 2 Test 3
Fish 3 Test 1, Fish 3 Test 2, Fish 3 Test 3
7. One fish was placed in each jar using the small net.
8. See “Directions: Weighing” for instructions on weighing fish.
-Weighing: (see diagram B)
1. Place one jar, with the fish inside, on the scale
2. Record the weight shown
3. Using the small net lift the fish out of the jar for a few seconds, long enough to record the weight of the jar without the fish.
4. Minus the second weight from the fist. What you have left is your fish’s weight.
(First weight – second weight = fish’s weight)
5. Repeats steps 1-4 for each fish. Do this every second day for two weeks.
1. Feed Fish Set 1 five flakes (of the same size) of the fish food in the afternoon.
2. Feed Fish Set 2 five flakes (of the same size) of fish food in the...