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The Behavior of Aquarium Fish Explained

Updated on November 12, 2018

The world of aquarium fish and how they behave in the water tank

How fish breathe in water

I will begin the topic by explaining the behavior of fish breathing in water. First there are good aspects and aspects of fish living in water. We know that water is around 1,000 times as dense as air, and contains much less oxygen. For several fish, the oxygen content of the water, and their ability to breathe it, makes the difference between life and death.

All fishes get oxygen by passing water over their gills. The gills are blood-rich filaments that are kept out of harm's way behind the operculum, or gill cover. As oxygen in the water passes over their, it passes through into the blood, which is continuously flowing through the gills. If there is insufficient oxygen in the water, the fish will breathe very rapidly and will appear to be panting. They may hang around at the surface of the water and trying to breathe from the atmosphere. If an aquarium is overstocked with several fish, this may be likely to happen. Oxygen enters the water by being dissolved at the water surface, so the more turbulent the water is at the surface the more oxygen will be dissolved.

Filters perform this function as an extra advantage, by disturbing the water surface as the water returns to the tank from the pumps. But, if the fish are dependent on this extra oxygen and the filter becomes clogged or breaks, then the oxygen will reduce rapidly and the fish will start to suffocate. Fish can also experience breathing difficulties it the gills are damaged. This can happen if they are in contact with chlorine, which is a known poison to them. If the new water is not dechlorinated during water changes, the fish may seem to be fine, but their gills might have suffered damage.

wikimedia (public domain worldwide)
wikimedia (public domain worldwide) | Source

How to understand and care for fish living in water

Generally, fish are totally and utterly dependent on the water in which they inhabit. They breathe it, drink it and are constantly bathed in it. It is not astounding, therefore, that if the water is polluted they will become unhappy. If the water is seriously foul or contaminated, of course, they will obviously die. However, if the water contains just a little bit too much ammonia, or poisons enter it may not be enough to kill them but just enough to make their life difficult. Such contaminations of poison can be from tap water which is not dechlorinated, air fresheners sprayed too close to the tank, or a touch of fly spray. Bad water may irritate their skins, causing permanent itching. It may also damage their gills, in other words, they have to work for every breath to survive. Although such things may not kill the fish instantly, the individuals in such an aquarium will suffer continually from minor ailments, which will recur as soon as they have been treated. In such situations, continually dosing the fish with remedies will have no real effect. However, if given some clean healthy water the disease outbreaks will stop.

One of the good aspects of fish living in dense water is the fact that the water supports the body of the fish. If a person was relaxing totally in water, they will fall over, but a relaxed fish remains in the same place. They only need to use energy to actually move. For this apparent reason it is easy for a novice breeder to overfeed fish. To give fish a hearty meal on the same scale as you a human, dog or a cat would be to give it far too much food. The extra food will either remain uneaten or be swallowed and excreted with no nutrition taken out by the fish. This excrement will rot very quickly, and it will overload the filters and contaminating the water in the aquarium. Basically, if the water becomes foul, the fish is likely to die from it.

Giving a pet fish happiness and joy is very simple to achieve, as long as they have enough air and food and are not living in bad water. Fish are also happy and secure if they are certain that, at any given moment, they are not about to be eaten by another fish. The fact of whether or not there is another fish in the tank that might eat them is not relevant. That is because fish in nature are never too confident about what might at that very moment be heading upstream towards them. All fishes have developed numerous ways of dealing with this prospect of imminent death.

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wikimeidia (public domain worldwide) | Source

Behavior of shoaling, aggressive and territorial fish

Some fish are shoaling, in other words, they live in big groups of their own types. When a fierce predator finds a shoal, the large numbers of fish milling around may baffle it, and furthermore the odds of any particular individual being eaten fall depending on the number of alternative snacks it is shoaling with. If a shoaling fish is kept alone, it will be sad and depressed, not because it is lonely, but because it believes it is in jeopardy of becoming dinner for another fish. Other fish rely on being able to blend into the background, or sometimes they hide in plants or caves.

Some particular fishes are bullies and will trouble other fish, even the bigger ones. A naïve fish which is unable to escape from another continually nipping at its fins and chasing it will also be very distraught. An elated group contains fish that are of roughly the same character and temperament. With some fish that are prone to aggression, it is advisable to keep large groups in the tank. The belief behind this is that although the mighty and dominant fish will not become any less nasty, they will have abundant of choices to vent their spite on. Thus it is not one poor individual who will continually bears the brunt of the attacks alone. Getting rid of the main offender will not help, as the next fish in the pecking order will simply assume the next dominant fish in line.

Dwarf gouramis (Colisa lalia) are both shoaling and territorial fish. If there are several of them in an aquarium, they will swim together, but if there are only a couple they will to establish their own territories. If there is not quite enough room for this in the tank, some fish will be bullied and harassed to death to make room for them. If breeders are thinking of keeping these fish, it is better to keep a single male fish, which will not trouble attacking fishes of other species, as the male only feels his territory threatened by other male dwarf gouramis.

Fish Fighting Over Territory

Some fishes are territorial and will require a small part of the tank to dominate as their own area. This is primarily true of those fish that guard their eggs, and need to establish a safe place for the spawning. Breeders may think a 1 meter (3ft) tank is sufficiently large enough, a fish from a big lake cannot be expected to see it in the same light. These fish can be helped by creating separate territories by using décor and ornaments for the aquarium to break up the line of sight, so that each individual fish in its own territory cannot see the one in the territory next to them.

Certain fish will become stressed and agitated by other fish trespassing on their turf, but more aggressive species will regard offense as the greatest form of defense and launch an attack, sometimes fatal, on the unexpected invaders. Fish that guard their eggs often offer other pitfalls for the owner of the fish, or breeder. While their owner might assume that a male and a female duo will be very happy together and that nature will take its course, the path of true love is often not smooth in the fishy world. To simplify, in many particular species of fish, if a female approaches a male's territory, the male believes it is because the female wants to spawn. If the female fish is there simply because there is nowhere else for it to go, then fatal disagreements are likely to spark up.

Let's assume that the female fish is in fact really searching for a male partner and that the joyful couple manage to pair up and produce some eggs, the happy male, or father, may suddenly realize that his female partner is now feeling hungry after all that hard work. Of course, it is evident the nearest snack available is fish eggs and the female fish is aware of it. For this apparent reason, males often become very angry towards their partners after spawning, and may attack or kill the female fish if she is reluctant to leave his territory. This kind of behavior is quite anti-social and need to be counteracted by the breeder. To do this, the breeder has to provide plenty of décor that breaks up the line of sight so that the female fish can avoid the male fish during the times she is surplus to requirements and desires.

Happy and Peaceful Aquarium Fish

Stressful Fish

A fish can certainly die from stress, and unlike humans, fish don't suffer from a nervous breakdown. When it is stressed, it will feed itself properly, and being to afraid to come into the open for nourishment. It even weaken the fishes immune system, and can get diseases, such as fungus or white spot. Fish are also known to be stressed by dirty and polluted water, so a water change regularly for the breeders is essential.

There are some symptoms of stress in fish, and it is very noticeable by the keepers of fish. Certain signs of stress in fish are when they try to jam themselves into corners of the tank, dart about frantically, or sometimes they change color. When fish are upset, they will turn very dark or very pale, and this warning sign should be noticed and dealt with by the owner responsibly. If the stress is way to extreme, fish may jump out of the water and die by either escaping the tank or banging themselves on the glass of the tank. By observing the fish, people can learn their normal behavior routines and colors, and quickly be able to see if they are behaving unusually or are colored differently. As a matter of fact, fish rarely change their behavior patterns just because they desire a change, however, if an active fish is behaving normal and it suddenly starts hiding or a greedy fish stops feeding, there will certainly be a cause behind this behavioral effect.



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