Overweight Fishes: Can Fish Get Fat?

Hi, this is your friend Clifton Ervin, the founder and chief editor of this site, Aquariumwolf. I completed my graduation in marine biology and became...Read more

The size of a fish tends to increase over a period. This can be due to some factors, ranging from overfeeding and some abnormalities. However, the occurrence could make you ask some questions such as, can fish get fat? Why is my beta fish looking bloated, or why is the stomach swollen?

It is uncommon for a fish to get fat in the reservoir due to limited food and competition. However, beta fishes could get fat due to pregnancy, overfeeding, and hygiene. Also, diseases like dropsy, Hexamita, etc. can make a beta fish get fat.

The diet of beta fish can make them look swollen or overweight. Also, eating the wrong type of food or overfeeding can cause digestive issues. As a result, it is ideal to feed beta fish with the right type of food to monitor their size. To better understand this, continue reading.

Can A Fish Get Fat; What You Need To Know

A fish in a reservoir cannot get fat because of competition and limited food supply. This means they only eat when they have access to food. As a result, their next meal may take quite some time. However, most fat cases in a fish are only associated with a fish in a tank or a beta fish.

Can A Fish Get Fat

Meanwhile, not all beta fishes with swelling are fat. Infections cause some. These infections are more like abdominal and girth swelling. However, for farmed fishes, weight gain is essential for sales, while it could mean differently for beta fishes.

Betas and Fat

All species of betas are prone to getting fat, but the ones in the wild are not. They store a large amount of fat to survive between meals. These fishes have long fins and, of course, numerous colors. The fins inhibit their movement and cause them to be less active.

Betas and Fat

Betas’ lack of external movement leads to low metabolism after feeding. As a result, they get fat quickly. For instance, a betas ideal food has fillers which may be low-quality food or grains. But if it’s a meal the beta doesn’t digest, it will be stored as fat.

Overfeeding in Beta Fishes

Offering excess food to betas often makes them swell. Overfeeding can easily lead to constipation when the wrong meal is given. A good indication of overfeeding is when the fish release excess waste, uneaten food, smelly odor, and algae. A fish could die if those overfeeding indications are not handled.

You can watch the following video for more information.

4 Overfeeding Signs

  • Excess Fish Waste: If a fish overeats food. It will excrete excess waste. This is indicated by strings of food waste attached to the fish’s body. However, when this is noticed, feeding should be discontinued for a while until it stops.
  • Uneaten Food: When you drop food in a fish tank or an aquarium, the fish quickly eats it. But, if you notice that the food is still in the tank for some time, it’s a sign of overfeeding. So, the thing to do is to scoop out the food immediately.
  • Algae: Excessive food in a fish tank translates into brown or green slime. This slime can coat the surface of the tank converting it into algae. So when excess food is consistently poured into the fish tank, more algae will continue.
  • Unhealthy Odor: The combination of waste, rotten food, and bacteria activities leads to an unhealthy odor. This can be dangerous to the environment and toxic to the fish. You can address this by changing the water and cutting down on feeding.

Pregnancy in Fishes

A good reason a fish may look fat is that it is carrying eggs. If the fish is a female fish, it is very likely she will become fat with eggs which is perfectly normal. A male fish is more brightly displayed than a female. However, you still need to examine the fish properly to be sure the increase in size is not overweight.

Pregnancy in Fishes

Meanwhile, ensure the female fish is not egg-bound. A fish is egg-bound when the fish moves around hastily due to an unsafe environment for procreation. Now for the eggs to be released, a male fish needs to be present, and the water needs to have the right temperature.

For more information:

Physical Pregnancy Changes

To determine a pregnant beta fish, a lump shows beneath the abdomen. This lump stays for 20 to 40 days, indicating the formation of eggs. The fish’s abdomen appears square when the beta fish is ready to give birth.

But one of the best ways to know a pregnant fish is a very dark spot beneath the fish’s abdomen.

Changes in Behavior

A pregnant beta fish tends to be shy and hides by the foliage of the aquarium. The movement will also be less than usual during pregnancy. Additionally, the beta fish will eat less food if she’s pregnant.

How Hygiene Affects The Size Of A Beta Fish

Improper maintenance of the aquarium can cause a beta fish to get fat. This improper maintenance includes dirt as well as a wrong fish diet. However, when your aquarium is gloomy due to uneaten fish food, fish waste, and algae, then a swollen or bloated fish should be expected.

Also, not changing the tank’s water constantly can destroy the digestive tract of a beta fish. It can also lead to constipation in a beta fish.

The water in the fish tank should be changed 20-25% per week. Every water and uneaten food should be scrubbed out regularly. Always check to ensure that the color of the water is bright as it was when you first bought the tank.

Watch this video for more information:

Diseases and Fat in Beta fishes

Some diseases cause bloating in beta fishes which are often mistaken as fat. So when you notice your fish getting big, call a vet doctor to know the type of disease it has. Below are the diseases that affect fishes:

1. Dropsy

Dropsy happens due to taking in a large amount of water without discharging it. This disease is dangerous to a beta fish but can be managed with the proper treatment.

The very first sign of Dropsy in beta fish is obesity and bloating.

2. Constipation

Constipation can cause bloating or swelling in a fish. This swelling affects the swimming ability of the fish. A constipated fish gives out reduced waste and sometimes no waste at all. But when they pass out waste, it is usually hard and trailing.

Here are some causes of constipation in a fish:

  • Dirty water condition
  • Overfeeding
  • Infections
  • Incorrect diet

Constipation leads to the death of the fish if nothing is done about it.

3. Hexamita in Fishes

This disease causes fish to have a hole in their heads; it can also cause bloating and swelling. This is very complicated or dangerous to handle. Apart from bloating, it is very challenging to detect this illness.

4. Viral Infection

This bacteria or viral infection causes a fish to be swollen. This disease can damage the fish’s immune and digestive systems. The clear symptoms of viral infection include:

  • Protruding scales
  • Bulging eyes
  • Red gills
  • Curved spine

5. Tumors

This disease is another reason for fish swelling. However, tumors are usually benign and misshaped unevenly. If the tumor is cancerous, there is a high chance of death. The tumor causes the fish to get swollen from one part of the body.

Generally, most tumors are not cancerous, but some are. So, a fish with a tumor should be kept differently from other healthy fishes in the aquarium.

For more information, watch this video:

How To Make A Beta Fish Lose Weight

For a beta fish to lose weight, offer less food and provide exercise. However, the best way to do this is to cut half of the fish’s food for two weeks. This will enable your fish to lose weight without starving it. If there’s no response from exercise and diet, consult a vet. The vet will give you tips to drop the weight of your fish.

For more information, watch this:

Bottom Line

Can fish get fat is one of the questions we hear many times. It’s the Beta fish that get fat with excess food, disease, and no exercise. To prevent this, give the right amount of food and create a large space to enable the fish to exercise very well.

However, to know if your fish is overweight, check the abdomen. Meanwhile, cutting down food quantity and consulting a vet becomes ideal when you notice excess fat.

Hi, this is your friend Clifton Ervin, the founder and chief editor of this site, Aquariumwolf. I completed my graduation in marine biology and became an Ichthyologist. One of my favorite hobbies is aquarium keeping; therefore, I love to talk about fish keeping, breeding, food behavior, etc., and much more relevant to aquarium maintenance. I have created this site Aquariumwolf, to share my 20 years+ of experience and knowledge with all new to this journey.

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