We all wish we could talk to pets sometimes. What are they thinking? Are they hungry? Do they feel ill? All living things have different forms of communication, but one thing that helps us to understand the needs of our animal friends is their behaviour. Your fish exhibit certain natural changes and behaviours that tell us when they require attention, like changes to their aquarium water, when they are hungry, when they are mating, etc. While some of their behaviours should not flag any concerns, some actions are a cry for help. To help you de-code what your fish are trying to say to you, we have gathered the following information:
Fish hiding all the time:
When fish are first introduced to a fish tank, are almost guaranteed to hide. Given that your aquarium water parameters are good, your new fish will ease itself out of hiding and begin to feel comfortable in its new home. If you have fish that have been in your tank for a while and they seem to always be hiding, there are a few different reasons:
- You have added incompatible fish to their environment. If your fish are feeling threatened by newcomers to the aquarium they will retreat into hiding.
- If they are shoaling fish by nature and you have not put enough of the species in your fish tank, this will cause them to be very shy and hide.
- Any change to your fish’s environment can cause them stress and make them hideout.
Fish nipping each other / fighting:
Fish fight for a variety of reasons – territory, resources and natural aggression are some of the main reasons that your fish will chase each other and nip at fins. If you plan to keep naturally aggressive fish, like cichlids, you need to ensure your tank is large for them to establish their territory and it not be encroached on by the other fish in the tank. Make sure you watch your fish during feeding time so that you will know if any fighting occurs over food and one is not getting enough to eat.
Fish swimming erratically:
If you notice your fish darting around the aquarium and swimming around erratically continue to observe them for a day or 2. If this behaviour is short lived then there is nothing to worry about. This could have been a form of play for your fish. If this swimming behaviour persists, it could be due to poor water quality. Some causes of this poor water quality can be incorrect pH levels, ammonia build-up, high amounts of nitrates or nitrites, or temperature changes.
When you observe your fish, check to see if they are bumping into / rubbing up against any ornaments or gravel. If so, this erratic swimming behaviour could be a sign of an external parasite. If you notice anything on their scales, a parasite treatment should be given to them right away.
Fish appearing lethargic/tired:
Slow-swimming or ‘tired’ fish are usually the result of tank water being too warm or too cold for them. Make sure to regularly check your aquarium thermometer to make sure the water temperatures are suitable for your fish species. If temperatures seem to be dropping continuously, check your aquarium heater to make sure everything is working properly.
If your aquarium water temperature seems to be spot-on, your fish’s inactivity may be due to overfeeding. Only feed your fish as much as they can consume in 2-3 minutes and remove any excess food left behind after that.
Fish sitting at bottom of tank:
If you notice your fish hanging out at the bottom of your aquarium, this is not always something to fret over. In fact, when fish sleep they tend to hover just over the bottom of the tank in a still, dream-like state. There are also bottom-dweller fish species that spend almost all of their time on the bottom of the tank or even burrowed in the fish tank substrate.
This being said, if your fish are not bottom-dwellers and this behaviour becomes regular, it could be a sign of disease. You may want to quarantine your fish that is displaying these signs and make sure they are treated appropriately. One common disease that would cause this behaviour is swim bladder which can be caused by poor diet and poor water quality.
Fish gasping for air at the surface:
If you notice that your fish are often swimming to the surface of the fish tank and sucking air from above the surface of the water, this means the oxygen levels in your tank are not sufficient enough for your fish to thrive. There are a few measures you can take to improve oxygen levels:
- Increase aeration; make sure you have an air pump or air stone that will provide oxygen bubbles directly in the water. It is important to keep the surface water in your aquarium agitated so that the oxygen exchange between the air and water can occur.
- Decreased oxygen levels can also be due to insufficient filtration. Make sure your filtration system is working properly and all the parts are up to date and cleaned.
- Or, your fish tank may be overcrowded. If your aquarium is too small for the amount of fish that you have then they will struggle to get enough oxygen to breathe. Please make sure you research fish species before purchasing to ensure you have the right aquarium set up.
Fish are not eating:
If you notice that your fish have stopped eating, this can be a sign of stress or illness. Fish can become stressed when they are transported for moving or cleaning purposes or when there are sudden changes in temperature in their tank. In order to limit stress on your fish it is a good idea to carry out more regular partial water changes (around 20%) rather than less frequent, larger water changes.
Another reason for your fish not eating could be an illness. Observe your fish’s eating behaviour as well as other symptoms such as abnormal swimming and sitting at the bottom of the tank. If you notice these abnormal behaviour signs, your fish may be suffering an illness and will need treatment.