Death for any being is often a sign of deep sadness. Most animals, especially dogs, are very aware when a loved one passes away. It even happens that the latter enter a phase of mourning.
But what about fish, do they know when one of their fellow creatures dies? Are they sad? Do they have emotions?
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Do fish realize other fish die?
Don’t be fooled, fish realize when one of their fellow fish dies. They see it with their own eyes when the fish floats upside down on the surface of the water. But what about their reactions?
It is often quite complicated to discern what is going on in a fish’s head, is it sad? Is it happy? What does it feel? We give you some hints.
Do fish get sad when other fish die ?
We explain below how scientists have managed to prove that fish have feelings. In this way, fish are obviously affected by the death of another fish.
It is complicated to talk about sadness, indeed, there is no doubt that they are impacted by such an event, however, it is also likely that fish do not experience emotions as we do.
Do fish have emotions?
While earlier studies hypothesized that fish could have feelings, recent research finally proves it. There are indeed biological signs that fish have the ability to feel emotions, and therefore sadness.
Of course, fish do not speak, do not cry and do not have facial expressions. Thus, the researchers instead investigated biological signals (cortisol levels in the blood) and other behaviors (flight, social interactions), already identified in other mammals such as primates.
Moreover, these tests were based on an animal model of “feeling”, linking positive feelings to certain brain regions. Researchers have done this type of testing in sea bream.
How to know if a fish is sad?
In order to detect a behavioral disorder, it is necessary to recognize the normal attitude of a fish, which depends on the species. As a general rule, a fish swims briskly, fins extended (except for bottom-dwelling fish and loricarids, for which immobility is not an alarming behavior). It interacts with its fellow fish, searches the ground, inspects plants and scenery… It breathes calmly and regularly, and comes quickly to eat when you distribute food.
The abnormal behavior of a fish is a common sign of stress or disease. An apathetic individual, lying on the ground, not eating and hiding away from other fish should alert you, if another fish died in the same tank, it is probably the cause of this behavior.
A fish that does not swim upright may have a swim bladder problem, and an animal that pipes air at the surface is suffering from a lack of oxygen. A fish that actively rubs against the decorations and accessories of its tank is scratching: it is probably infested with parasites.
How to remedy a fish’s troubles?
To begin with, the most important thing is to remove the dead fish from the tank as soon as possible. As for the rest, the cause must be determined. If the problem is pathological or due to stress, the disease should be treated, the aquarium parameters should be checked and corrected if necessary.
If the abnormal behavior is due to poor cohabitation or overcrowding, the tank population must be rebalanced.
For this, it is sometimes necessary to separate some fish, by giving them to other aquarists for example. A simple readjustment of the decor and the creation of hiding places can also help to get rid of the troubles.