Fish Health

Cowfish Lifespan- How To Increase Their Lifespan? Find Out The Truth

Pinterest LinkedIn Tumblr

Cowfish, as its name suggests, does look like a small cow swimming inside your aquarium. The little horn, their body structure, and their body movement will pause your thought for a while. Not only that, in a few minutes of knowing cowfish, you will find yourself searching in google about them. You will be left astounded with their lifespan, and who knows, you might end up making a plan to adopt them.

Cowfish is one of the blessed fish that has a long lifespan compared to other aquarium species I know. Having said that, normally, these fish can live up to 8 years in your aquarium and up to 10 years growing into 20 inches long in a natural space. And, if you wish your Cowfish to live more than 10 years and increase their lifespan then, check on what you are missing!

With Cowfish, it will be love at first sight and, you will want to adopt them badly but, love does not come easily, right? Besides, you should know these fish are not for the beginner or intermediate keepers but, if you are an experienced marine fish keeper then, you can continue reading.

Quick Overview On Cowfish

Before entering into the depth of Cowfish lifespan, let us briefly know this fish from the table drawn below:

Common Name Longhorn Cowfish
Genus Lactoria
Origin/ Habitat Indo-pacific region
Species L. cornuta (Lactoria cornuta)
Class Actinopterygii
Color Yellow color with white spots
Kingdom Animalia
Price $50
Size 20 inches
Diet Omnivore
Lifespan Around 8 years
Tank Size 250 galloon

What is Cowfish?

Cowfish (longhorn fish or boxfish) are charismatic fish and look adorable when you look closely and a bit strange when you look from a distance. These fish are originally found in the Indo-pacific region, such as India, Japan, Korea, and Indonesia. 

Similarly, cowfish are recognized by their two little horns that grow naturally back within a few months, even if they will fall or break. Their cow-like horns, the hard shell-like body, acts as a shield against the larger predators and give them the appearance of a cow or a bull instantly. Thus, I call them a marine cow.

Furthermore, Cowhorn fish have independently moving eyes that let them watch in two different directions exactly at the same time. Apart from their eyes, The fish has captivating yellow-colored skin with white or blue dots here and there. But, their skin is poisonous and will release life taking toxin called ostracitoxin through the skin’s mucous secretions in the water when they feel threatened or stressed. Thus, the poison will kill the species in the aquarium including, cowfish.

Most importantly, Cowfish does not have a pelvic skeleton, are scaleless, and -do not possess fins on their pelvis area. And because of their scaleless body, they are prone to illness and catching parasites easily. So, one needs to be extra careful about water quality. Hence, due to their inflexibility and their strangely unique body structure, they seem like they are hovering around when in fact, they are swimming.

How Long Does Cowfish Live?

Cowfish is one of the rare species that is blessed with quite an extended living period. These fish are expected to have a lifespan at least 8 years and sometimes even 10 years if everything is rightly taken care of.

Cowfish lives for more years when they are in their natural habitat with no territorial fish. Similarly, these fish tend to live a long and healthy life with natural food, natural surrounding, and the right water parameters.

Get interesting insights on “Can Fish Eat Human Food: What Are They And How To Prepare Them?”.

Nonetheless, cowfish tend to live a less and possibly unhealthy life in your given environment. Likewise, when they are supposed to swim around your tank for a lifetime with adjusted oxygen, filter, provided food, and an artificial environment, things might get risky! Meaning unintentionally, you will be responsible for cutting their living period short.

I have separated Cowfish lifespan based on the environment around them in the natural or captive environment.

How Long Do Cowfish Live In Natural Environment?

Who does not love their natural habitat, their origin place? Your cowfish loves them too! These fish naturally belongs to the Indo-pacific region, and the region does not have predators or cowfish hunters that let them swim freely.

Natural Setup For Cowfish

The more natural, the better! Likewise, natural setup as natural plants, natural diet (such as live crustaceans, live fishes, and forming algae), natural temperature, dissolved oxygen, and the natural filter will let cowfish live a healthy life. And, healthy life will automatically lead to a longer life.

Some recommended food are:

Similarly, Cowfish can swim wherever they want inside the sea. Also, they will not constantly bump into artificial decorations resulting in a stress-free life.

Tankmates Of Cowfish In Natural Environment

Mother nature has planned only desirable and friendly species to the sea/ marine area where Cowfish naturally belong to. Likewise, fish as seahorses, other boxfish, and pipefish are normally found in Indo-pacific regions, and these species are no harm to Cowfish in general.

How Long Do Cowfish Lives In Captive Environment?

A captive environment is any confined or artificial environment that you are giving to your fish. The environment could be your aquarium or your small pond with a limited area. However, the water parameter, diet, filter, tank setup, and everything are decided by you only.

Tank Setup For Cowfish

Cowfish is known as a silent explorer so they need a spacious tank where they can float freely. Likewise, when cowfish is small, you can put them in 100 gallons of a tank but for an adult or a growing fish at least 250 gallons of the tank is suggested. Also, do not overdecorate your tank as these fish will keep bumping into them and they might feel stressed overtime. 

Tankmates For Cowfish

Similarly, Cowfish are peaceful and friendly fish and require similar kinds of fish sharing similar traits. So the smaller and less threatening fish, the better.

As when they feel harassed and threatened, they will release a destructible amount of poison that will result in a sad and unintentional massacre. Since cowfish are not immune to their toxin, they will die too. 

Diet Habit For Cowfish

However, a constant healthy diet is another significant requirement to lengthen cowfish lifespan. More natural food as a slice of meat, shrimps, tin crustacean, vegetables, and crab are suggested. Hence, feeding them well is a must!

Water Parameter For Cowfish

Lastly, the vital part is the quality of water. I have listed the right water parameter that is to be followed when housing Cowfish in your aquarium.

  • PH level: 8.0 to 8.3
  • Temperature: 77 to 78 degrees Fahrenheit
  • DKH: 8DKH to 12 DKH
  • Salinity: 1.020 to 1.025
  • Nitrates and ammonia level : 0 or the lower side

Therefore, cowfish can die in 6 months or live up to 8 years in your aquarium. This all depends on you!

Frequently Asked Questions On Cowfish (FAQs)

There are few frequently asked questions on google regarding Cowfish and, they are answered below:

Are Cowfish Poisonous To Humans?

Surprisingly, the toxins released from Cowfish are only poisonous to aquatic species and not humans.

Hence, no, Cowfish are not poisonous to humans.

Are Cowfish Hard To Keep In Your Aquarium?

There are many things to consider before housing cowfish in your tank. Similarly, their nature of releasing life taking poison into the water, their tankmates, giant tank size, healthy water parameter, expensive food habit, scaleless body, and their nature of being easily stressed are the things to consider.

Following that, as lovely as it seems to house Cowfish in your tank, You need to realize these fish come will all the consequences. I do not recommend beginners to adopt these fish. Hence, I suggest only experienced marine fish keepers to house these fish.

Can Cowfish Die On Their Own?

Yes, Cowfish can die on their own but not willingly. When these fish are highly stressed or are ill, they release a poisonous toxin in the water that does not only kill the species of your tank entirely, but the same poison will kill Cowfish too.

Therefore, as sad as this entire process sounds, I believe this is an urgency to place cowfish in a different aquarium when you feel wrong in their behavior immediately.

How Fast Do Cowfish Grow?

Cowfish is a very slow grower, but the growth depends on what environment you are giving them, from food to correct water parameters and from a wide area to their tankmates. You must choose all these requirements carefully.

Also, I have seen Cowfish grown up to 17 inches long in an aquarium for 9 years. So, I believe the growth of these fish depends upon their diet and water quality. Thus, the growth rate depends on the lifestyle your fish is receiving.

How Many Types Of Cowfish Are There?

Normally, there are two types of Cowfish known worldwide: scrawled cowfish and the longhorn cowfish.

Scrawled cowfish has a scrawled blue marking all over the body. Likewise, they do not have pelvic fins and dorsal fins and have two little horns that give a slight resemblance to a cow. Besides, these fish are blue-green colored that will darken with time. 

On the other side, Longhorn cowfish has a longhorn with a scaleless body. Similarly, these fish are yellow-colored fish having white or blue spots all over the body. The color will darken at night time and brightens during day time. Likewise, their body is inflexible due to the absence of a pelvis skeleton. Hence, whenever they swim around, they will seem like they are hovering.


In conclusion, housing Cowfish seems like a lot of work as you need to watch for their everything and divide your savings for their food, heater, filter, and tank decor, but is it worth it? definitely YES!

Above all, if you are doing everything right, the lifespan of Cowfish will grow. And, if not, at least you will learn to house aquatic species. 

Related articles: