Close this search box.

Aquarium fish

Introduction to Aquarium Fish

An aquarium, also known as an aquarium or an aquaria, is a type of vivarium that has at least one transparent side and is used for the display of aquatic plants and animals. Aquaria are used by fish keepers to house a variety of aquatic organisms, including fish, crustaceans, amphibians, aquatic reptiles like turtles, and aquatic plants. Philip Henry Gosse, an English naturalist, is credited with the invention of the name “aquarium.” It is derived from the Latin root that meaning “water,” aqua, and the suffix that means “a location for relating to,” -arium.

Gosse was the one who initially popularized the keeping of aquariums in early Victorian England. In the year 1853, he established the first public aquarium in the London Zoo and stocked it with aquatic life. In the year 1854, he penned the very first book about aquariums. An Expos√© on the Marvels to Be Found in the Ocean’s Depths.

Aquarium Fish Tank

Small aquariums are commonly kept in people’s homes as hobbies. Many cities have huge public aquariums that are open to the public. In public aquariums, the fish and other aquatic species are housed in large tanks. These tanks can also house other aquatic animals. In a large aquarium, you could see whales, dolphins, sea turtles, otters, and sharks, among other animals. Most aquarium tanks also feature plants.

Aquarists are responsible for the ownership and maintenance of aquariums, which are often constructed of glass or durable acrylic. Aquaria that have the appearance of cubes are sometimes referred to as fish tanks or just tanks. Aquaria that have the appearance of bowls are also referred to as fish bowls. The volume may be as little as a few liters, as in a miniature glass bowl, or as much as thousands of liters, as in a massive public aquarium.

Goldfish Bowl Aquarium


The majority of fish kept in aquariums nowadays are farmed aquarium fish. This not only helps save time and money, but it also prevents the natural ecosystem from being disturbed in any way. In addition to this, the fish are tougher, and there are a greater number of them.

On the other hand, there are significant distinctions in the various fish that are offered. How the fish are bred and grown has a significant impact on the overall quality of their health. Because of this, you should avoid purchasing fish from anyone who cannot be trusted. This can help prevent disease from spreading throughout your aquarium or from acquiring fish with compromised immune systems that are more likely to perish shortly after being purchased.

To provide a healthy environment for a fish, it is necessary to be familiar with both its species and its native environment. One type of fish, the catfish, may be discovered in both saline and freshwater environments all over the world, and there are over 2,000 distinct varieties of this fish. Cichlid fish can also be found in South America and Africa in addition to Asia. Each all come from various regions, and in order to thrive in the aquarium, they require a unique set of conditions and supplies.


The majority of the creatures that live in an aquarium are omnivores, which means that they consume both plant and animal matter in their diet. When selecting food for fish, one must also take into consideration the method by which the fish consume their food. There are a variety of sorts of food that are beneficial to various species, some of which reside on the ground while others float in the plants or in the center of the water.

Fish flakes

The majority of customers purchase this particular variety of fish food. It is universal, which denotes that any variety of fish in any section of the aquarium is able to consume it as food. To begin, it is seen to float on the top of the water. After that, it sinks to the bottom of the aquarium and shatters into pieces all over the water, making it accessible to fish in the aquarium that prefer to feed in lower locations.

Fish pellets

Excellent food for fish that feed at the bottom of the aquarium or in the center of the tank’s water. They come in a variety of sizes and can sink at varying rates depending on the size. They are able to gently absorb water, maintain their stability in water, and only release a little quantity of their components into the water because their structure has a smooth surface and closed pores, which allows for these characteristics.

Tablets for fish

The finest feature of them is that you may adhere them to the wall of the aquarium or place them at the bottom of the tank. Bottom fish, crustaceans, and fish that feed in the center of the water can all benefit from being fed these foods.

Fish sticks

The food that is found floating on the surface of the water is consumed by larger and medium-sized fish.

Fish wafers

Crustaceans and fish that feed in the bottom zone will find the wafers to be an ideal food source because of how rapidly they sink to the bottom of the tank. This meal has a low water absorption rate, which allows it to maintain its form for an extended period of time. This is an ideal situation for fish, because their teeth are adapted to scrape food off of a variety of surfaces.

Natural foods

People have the misconception that natural food is the greatest thing for fish to have in an aquarium. Herbivorous aquarium residents will consume things like algae, vegetables, or aquatic plants, whereas carnivorous fish will devour other living things, such as other fish or other aquatic plants. In conclusion, the following are a few pointers. Feeding little fish and fish with mouth openings that are not very large should be done using flakes and micro grains. Flakes, pellets, tablets, and wafers are the most common forms of food for bottom fish. Larger fish that feed on food that floats to the surface of the water benefit the most from being fed chips and sticks.

Aquatic plant


Interesting facts

  • The tiniest aquarium in the world is only 30 millimeters in length, 24 millimeters in width, and 14 millimeters in height. It has a few juvenile fish, all of which are replaced as soon as they become too large.
  • At an aquarium in Auckland, New Zealand, in the year 2009, one shark assisted another shark in giving birth to its young. The pups were able to escape after the first shark gave the second shark a stomach bite, which caused an opening. According to one of the employees working at the aquarium, “It had to bite a precise location in order to pull the kids out without injuring either herself or the babies.”
  • There is an aquarium that has a height of 82 feet and can house more than 1,500 different species of fish. There is a glass elevator in the center of the tank that travels up and down the length of the structure. Every day, divers are required to clean it at least three or four times. The German Aqua Dom is the title holder for the title of world’s biggest freestanding aquarium.
  • A human arm was thrown up by a shark that was kept in an aquarium in Australia in the year 1935. On the arm, there were no signs of bite marks, and it appeared to have been cleanly severed with a knife. A guy shot himself in the head during the course of the inquiry, and then led police boats on a pursuit that lasted for several hours.
  • A Queensland lungfish by the name of Granddad has lived at the Shed Aquarium continuously from the year 1933. It is possible that he is older than one hundred years.
  • The Georgia Aquarium hosts adult-only sleepovers where guests get the opportunity to spend the night in the aquarium with the animals that live there.

Large Georgia aquarium

  • The term “aquarium” did not exist until to the opening of the one at the London Zoo, which is where the public’s first aquarium was located. In times past, people commonly referred to an aquarium as an aquatic vivarium.
  • Because no one has ever been successful in maintaining a great white shark in good health for more than half a year, aquariums do not have any great white sharks in their collections. The greatest success that might have been had at the Monterey Bay Aquarium was derailed when a great white shark killed several other sharks in an exhibit and then had to be released.
  • At the Melbourne Aquarium, a huge squid measuring 7 meters in length and weighing 3 tons is preserved inside of a block of ice.
  • At the Vancouver Aquarium, two rockfish each received a prosthetic eye to replace the natural eyes they had to remove since their cataracts had ruptured. Other fish saw the empty eye socket for a sign of weakness and attacked the two fish, damaging their fins in the process. To protect themselves, the fish fabricated a false eye to fool the other fish into thinking they were stronger than they actually were.

Whelping process

If your species of fish gives birth to live young or lays eggs, you should be able to determine this information with a quick search on the internet. This will tell you whether you should search for a pregnant tummy or for little jelly-ball-like eggs in the tank. If you do anticipate the arrival of new young fish, you should make an effort to learn as much as you can about the specific species you intend to raise, although it may be difficult to do it on your own.

A pair of Aquarium fish

Recognizing pregnancy and giving birth


Use this method for live-bearing species

Guppies, mollies, swordtails, and platies are the four species of live-bearing fish that are kept in aquariums the most often. The males and females of this species mate, and thereafter, the females lay their eggs within their own bodies. In the course of a month or two, the fish fry emerge from their eggs. The mother gives birth to her young (for most aquarium species).

  • Go online and look up the name of your species to see whether or not it reproduces by laying eggs (oviparous) or by giving birth to live young (viviparous) (viviparous).

Identify the males and females

Male fish of live-bearing species are often brighter or more intricately colored than females, and they have a thin, long anal fin on the lower side of their body close to their tail. Males also tend to have larger bodies. Females have a more muted appearance with an anal fin that is triangular or fan-shaped. If you are able to discern the gender of the fish, you will be able to tell whether or not they are fighting (typically between two males or two females), mating, or getting ready to mate (one male and one female).

  • Because it is more challenging to differentiate between some species, it is possible that you may want the advice of an expert at an aquarium store.

Look for signs of mating rituals

There is a lot of diversity among fish species when it comes to pair-bonding, amplexus, and other mating-related behaviors. In a number of species, including the vast majority of gouramis, the male gourami follows the females about and, on occasion, scratches, bites, or other types of injuries might result. When it comes to others, such as discus, a male and a female will work together to protect one section of the tank from the other fish in the community. When true mating occurs in any situation, the male and female may clasp each other, turn upside down, squirm around one another, or engage in a variety of other subtle behaviors that are difficult to observe.

Check for a pregnancy bulge

The abdomen of the female fish will develop a protrusion at its posterior end. The abdomen will often grow into a large, rounded form or a “boxy” shape sometime between the ages of 20 and 40 days.

  • Some species, such as balloon mollies, have a natural protrusion front of the gills in their body structure.
  • If a man is overweight, he may end up developing a protrusion at the front of his chest. If you skip feedings for two or three days, the bulge that comes from being overweight could go away, but a pregnant woman’s stomach will not go away.

Look for a red or black spot

Fish that are pregnant typically develop a “gravid spot” on their abdomens, typically in the region of the rear vent. This is typically a dark or very brilliant red color, and it gets more noticeable as the pregnancy progresses.

  • Some fish have this region at all times, but when they are pregnant, it will often become either brighter or darker than it was before.

Decide how to prepare for the young fish

The process of rearing young fish, often known as fry, may be quite challenging and generally requires a separate tank to ensure that the fry are not killed by the adults or the water filter. Calling an aquarium shop or an experienced aquarium hobbyist who could be willing to assist you with the procedure or take your fish is something you should do if you are not prepared for it. If you do make the decision to care for the young, you may start by reading the part on rearing young that is below, but it is also recommended that you learn as much as you can about your specific species of fish.

Nesting and egg-laying identification

Use this method for egg-bearing species.

Eggs may be carried by a wide variety of fish found in aquariums, including discus, betta, and the vast majority of gourami species. The females of this species lay hundreds of eggs in carefully made nests on the ground, the wall, or the surface of the water. It is possible for a male in the same tank as the female to fertilize the eggs after they have been laid or by mating with the female before she lays them. This depends on the species. In the end, the eggs will develop into fish that are still alive.

  • Do an online search using the name of your species to see whether or not it gives live birth (viviparous species) or lays eggs (oviparous species) (viviparous).
  • Because the females of some fish species may store sperm for several months before using it to fertilize eggs, it is possible for a new tank to produce offspring even when only females are present.

Watch for signs of nesting

Several species of fish that lay eggs construct nests in order to safeguard their young. These have the appearance of little pits or gravel mounds, however they are not always visible. Sometimes they may be seen. There are species of gourami that are known to construct complex nests out of a hive of bubbles, which are mostly produced by the male along the surface of the water.

Check for eggs

However, this is often a modest change that does not last for an extended period of time. Eggs only occurs in the females of this species they are developing within them. When the eggs are laid, they usually take on the appearance of little balls of jelly. These are commonly thrown into the water, but in other species, they tend to accumulate in a mound on the nesting spot or become stuck to the bottom or the side of the tank.

There are mating rituals performed by many egg-laying species, including the majority of gouramis. These are often physically demanding displays that may go on for a number of hours before the eggs are actually implanted.

Get ready for the eggs to hatch

It can be difficult to provide proper care for baby fish, often known as fry. However even if you are caught off guard, you will have some time before the eggs hatch. If you wish to grow the fry yourself, you should get advice from an aquarium merchant first. Methods differ according on the species. If you are caught off guard, you may look at the section on raising young fish for some general recommendations. You shouldn’t expect the technique to work perfectly for every kind of fish.