Health of Goldfish as Influenced by Various Environmental Factors - Report 1
Goldfish Keeping as a Hobby
Lastufka Labs16 May 2002
Investigators:
Primary: Arin Lastufka
Keywords: Goldfish, Goldfish Health, Experiments,

This article contains the abstract a brief version of the full report. The full report is available on request to those wishing to duplicate the experiment.

Abstract

Four goldfish were exposed to different environmental conditions and observed with the purpose of determining how their health was affected. Factor selection depended on conditions fish are sometimes exposed to by different hobbyists, as well as other factors which were already known to have a noticeable effect on goldfish. This was to verify the credibility of other observations. Two goldfish bowls were used, each with two resident fish. One bowl was designated the 'Control', while the other's environment was identical, excepting the factor under investigation.

Factor 1, sand in the 'Variable' bowl and gravel in the 'Control' bowl, was found not to significantly influence the fishes' health. Factor 2, darkness in the 'Variable' bowl with the 'Control' bowl exposed to light, significantly influenced their health; with extremely obvious reactions, such as decreased activity levels.

Background

Goldfish are among the most popular pets in the world. As a result, hundreds of books have been written on the subject of goldfish keeping. But how many are backed by scientific evidence? Most are based on casual observation and "experience".

But are they really right? And if they are, what effects do they really have on the fish? What about the subjects that get mentioned in passing - "either this or this is right"? Are they correct?

This set of experiments is easily reproduced, and full details are available on request. It must be taken into account, however, that all living organisms are unique, and there is a small probability that other fish might not respond in the same way to the same factors.

The only serious drawback in these experiments is the goldfish bowl, which is not recommended, because of the decreased surface-to-air ratio. However, this hopefully should be compensated for by the use of an air pump, which is not normally used in a goldfish bowl. There were, of course, natural variations in temperature and humidity, but as the bowls are were the same room at the same time, both were be subject to the same conditions. These are the same circumstances a hobbyist's goldfish would undergo.

Procedure

The conditions in the Control bowl were selected according to recommendations in 'the books' (bibliography included). The conditions in the Variable bowl were identical to those in the Control bowl, excluding the variable being tested.

Control bowl environment:

Glass 1 gallon goldfish bowl
Aeration airstone
Gravel depth: 7 cm
Plant Elodea
Place to hide broken garden pot (with no sharp edges)
Water changed once every week
No algae
Dechlorinated water
Light
Two fish per bowl

The "varied"(Control) diet was based upon recommendations by various goldfish hobbyists.

Feeding at 0700 hours:
1/12 teaspoon of crumbled dry flake food per bowl

Feeding at 1815 hours:
2 frozen, husked peas per bowl
1/12 teaspoon of freeze-dried tubifex or blood worms per bowl
Above foods to be alternated each day
24 hour time used for clarity

Observations took place at 0710 and 1805 hours (24 hour time used for clarity). These times were selected as they occured 10 minutes before and after feeding. Feeding was observed to stimulate action from the fish; therefore, observations before and after feedings should document the fish at their 'high' and 'low' points of activity.

Measured factors:

  1. Rate of Breathing
    Number of times operculum opens/closes in 15 seconds is multiplied by 4 to result in breath/minute.
  2. Activity Level
    A grid is placed on the front of the bowl, sectioning the inside volume into a three-dimentional grid of 18 cubes. The rate of activity is measured by the number of times a fish passes across a grid line.
  3. Eye
    A true/false indicator of health is the clarity of the eye.
  4. Fins
    A true/false indicator of health is whether or not the fins are held against the body (clamped) or away from it.

Water was changed every Sunday at 1700 hours. The slightly different changing times did not noticeably affect the outcome of the experiment.

Experiment 1 (Gravel vs. Sand): Sand substituted for gravel. Time: 13 days

Experiment 1 setup

Following the experiment, the Control bowl was renamed 'Variable', and the Variable redesignated as 'Control'. This was to avoid any possible effects of the previous factor upon the second experiment. The fish were then allowed a week to acclimate to their new conditions.

Experiment 2 (Light vs. Dark): Variable bowl covered with a light-obscuring bag to simulate darkness. Time: 11 days

Analysis

Much of the analysis of the data obtained boiled down to the table below.

Experiment 1

Averages Time Fish ID Rate of Breathing (breath/min) Activity Level Eye (Clear or Cloudy) Fins (Clamped or Not Clamped)
Control Average 0710 Alpha 81.23 6.08 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)
Beta 75.08 6.85 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)
Variable Average Delta 69.54 5.69 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)
Gamma 71.69 7.85 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)
Control Average 1805 Alpha 65.00 5.08 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)
Beta 69.33 6.00 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)
Variable Average Delta 65.00 6.00 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)
Gamma 68.67 6.50 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)

Experiment 2

Averages Time Fish ID Rate of Breathing (breath/min) Activity Level Eye (Clear or Cloudy) Fins (Clamped or Not Clamped)
Control Average 0710 Alpha 61.82 5.18 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)
Beta 61.45 4.27 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)
Variable Average Delta 72.36 11.27 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)
Gamma 77.09 12.00 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)
Control Average 1805 Alpha 66.91 5.36 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)
Beta 69.09 4.91 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)
Variable Average Delta 78.91 11.18 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)
Gamma 76.73 12.00 Clear(100.00%) Cloudy(0.00%) Not(100.00%) Clamped(0.00%)

Results

Experiment 1

There is no significant difference between the health of the control fish and the health of the variable fish. This is in accordance with the references, which mention sand and gravel with no indication as to which is more beneficial. Therefore, sand has no effects, or extremely trivial effects, on the health of a goldfish. However, gravel is probably more convienient for the goldfish owner, as the water becomes cloudy after bowl cleaning.

Experiment 2

According the analysis of the data, there is a significant difference in the health and activity of the inhabitants of the different environments. In the morning averages, there was a difference of at least ten breaths per minute, and a difference of at least six in the rate of activity. The evening averages differed by about nine breaths per minute, and about six in the rate of activity. It may be concluded that dimness adversely affects goldfish by slowing breathing and activity. Etoilation (abnormal elongation of stem due to lack of light) of the plants was also observed.