Fish Eggs: How Long Do They Take To Hatch And How Can I Identify Them?

Sakshi Thakur
Mar 28, 2023 By Sakshi Thakur
Originally Published on Dec 21, 2021
Edited by Rhea Nischal
Fact-checked by Pratiti Nath
Clown fish eggs super macro in Cebu Philippines.
Age: 3-18
Read time: 5.7 Min

Small beads of pearl on your dish can make it the most expensive dish on the menu.

Have you wondered what this special item may be? They are small packages of omega fatty acids and enhance the taste of your food.

Fish eggs or caviar are served in many parts of the world. There is caviar and roe that are used to cook food of a special kind.

The taste is heavenly and can transport you to the sea world. Caviar has been called the gold of the sea as it is the most expensive food item in the whole wide world. The price can go as high as $15,750 per lb ($35,000 per kg).

The caviar relished all over the world belongs to the sturgeon fish. It is interesting to know that sturgeon caviar has been used for over 250 million years now.

You may be astonished to know that there is a difference between caviar and roe. There are several types of fish roe. Actually, both the terms 'fish roe' and 'caviar' are names of fish eggs, but in a different form.

Most people are not aware of the difference, so the restaurants can serve you any fish eggs such as salmon fish eggs, and call them caviar. Caviar is true only if it is sturgeon caviar.

If you enjoyed this article, why not also read about can fish see in the dark, or how do fish mate here on Kidadl?

Are all fish eggs caviar?

No, all fish eggs are not caviar, as caviar is a term specifically used for the eggs of a special fish, the sturgeon.

All the others can be broadly named as roe, including caviar. But we cannot say vice versa. All roe is not caviar. Salmon roe or other types of fish roe from other whitefish, trout, ikura, tobiko, cod, and red caviar are often used as caviar substitutes. However, they are not caviar, and the flavor will not be the same.

Fish roe or fish eggs are rich in omega fatty acids and are good for health. They all have a salty flavor to them.

The beluga sturgeon is the larger fish of its family. It is mostly found in abundance in the Caspian Sea and the Black Sea. This species is specially harvested for getting caviar in the early summer season.

Tobiko, or flying fish eggs, are also commonly eaten as a delicacy in many parts of the world. It is reddish or orange in color and is used to make sushi roll dishes.

How do roe and caviar differ?

You must know that caviar and roe are both fish eggs. However, both are different from each other. Let's look at the minute difference that separates them. The difference lies in the marine animals they are harvested from.

According to the traditional way of defining it, 'caviar' is a word used only for the roe that is harvested from the fish of the Acipenseridae family, which is the family of sturgeons. It is mostly harvested fresh from the Beluga fish.

In caviar, there is a combination of unfertilized eggs as well as salt. An interesting fact is that caviar is known as roe until it has been salt-cured. It has a soft texture and can also be served cold in a few dishes.

Fish roe from salmon, trout, or other fish is called roe, even if it has been cured roe with salt. These are actually abundant in the wild.

While in a few restaurants, the salted trout roe is served as caviar, which is not true caviar. The FDA in America has allowed salted fish roe to be labeled as caviar, but the condition is that they have to specify the variety of fish along with it. In other countries, there are no such rules.

So, if salmon fish roe is served to you like caviar, that will be considered cheating. Caviar has to strictly belong to the sturgeon and no other salt-cured fish.

So, it can be stated that caviar is strictly sturgeon fish roe. Roes from all other fish are not supposed to be labeled as caviar.

Clownfish eggs closeup.

How do fish lay eggs?

Fish lay eggs and do not give birth directly to young ones.

Most fish lay a huge number of eggs as a part of the reproduction process. These are further fertilized and scattered outside the fish's body.

The eggs of pelagic fish remain suspended even in the open water. Many freshwater fish prefer to lay eggs on the bottom of the water body or even among plants to hide them from predators.

You may have seen that a few species have adhesive eggs. The mortality rate of the eggs is very high. Very few individuals finally grow to maturity. Thus, the success rate for these eggs is very low. It has been seen that there are sometimes millions of eggs laid.

Generally, fish’s eggs hatch in three to seven days on average. The incubation time totally varies according to the species and tank conditions. If the eggs turn white after a day rather than the usual light brown color, they are not going to hatch.

But do not start calling it or trying to eat these eggs as caviar. They are fish roe. All varieties may not be edible.

How often do koi fish lay eggs?

A female koi fish lays eggs once a year. They lay eggs in the spring (May or June).

There is no clarity as to whether you can eat koi fish eggs or not. They may seem to be orange, just like the ones used in a cured sushi dish. So rather than trying a new delicacy, stick to the traditional sturgeon family-cured roe or caviar.

What do fish eggs look like in a fish tank?

Fish eggs can stay floating or settle at the bottom, depending on the species. However, you will surely see the bead-shaped eggs in abundance.

Most fish lay eggs in huge numbers, as their survival rate is low in the wild. They will all stick together. At times, fish can stick these to the plants in the tank.

They may seem tempting and also look like caviar, but do not eat them. Caviar is very good for health as it has ample omega fatty acids, but they belong to sturgeon fish only.

You must leave the fish eggs alone and let them grow into young ones. Even after that, the survival rate is not high. You will see many of them die in the first few days.

If you have more males, then the fertilization may be high. Also, a single male is not able to fertilize all the eggs laid by a single female fish of the same species.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for fish eggs, then why not take a look at how often to feed fish or Brook Trout facts.


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Written by Sakshi Thakur

Bachelor of Science

Sakshi Thakur picture

Sakshi ThakurBachelor of Science

Sakshi is a skilled content writer with extensive experience in the education industry. With a keen eye for detail and a passion for helping others, she has developed a reputation for excellence in academic content writing. She has worked with esteemed professionals such as Mr. Kapil Raj, a professor of History of Science at the École des Hautes Études en Sciences Sociales in Paris, further enhancing her knowledge and expertise. Sakshi is well-versed in the latest developments in e-learning and has a deep understanding of how to engage students and make learning fun and accessible. In her spare time, she indulges in her creative passions, including painting, embroidery, and listening to soft music. She also enjoys exploring new cultures and traveling, which helps her broaden her perspectives and inspire her writing. She holds a Bachelor's degree in Science from Panjab University.

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Fact-checked by Pratiti Nath

Bachelor of Science specializing in Microbiology, Masters of Science specializing in Biotechnology

Pratiti Nath picture

Pratiti NathBachelor of Science specializing in Microbiology, Masters of Science specializing in Biotechnology

A Master's in Biotechnology from Presidency University and a Bachelor's in Microbiology from Calcutta University. Pratiti holds expertise in writing science and healthcare articles, and their inputs and feedback help writers create insightful content. They have interests in heritage, history, and climate change issues and have written articles for various websites across multiple subjects. Their experience also includes working with eco-friendly startups and climate-related NGOs.

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