Do Fish Lay Eggs? 90 Percent Of Bony Fish Do

Do fish lay eggs let’s investigate. There are many thousands of species of fish all being weird and wonderful in their own way but what about laying eggs?

We’ve all heard of fish giving birth to free-swimming babies called fry. These fish are called livebearers. There are also nesters who build a nest for their young also mouthbrooders and of course, there’s the whole spawning.

Let me explain keep reading and ill start by answering the question and then examine it in more detail.

Do Fish Lay Eggs

Yes, Approximately 90% of bony and 43% of cartilaginous fish are oviparous meaning these fish spawn eggs releasing them into the water to be fertilized and then hatching into fry.

So some fish do indeed lay eggs or spawn as it’s known ok but how do they do this is there a process and how often. Well, let us take a deeper look at the processes involved in fish spawning eggs.

How The Eggs Are Made

Yes, the eggs are made unlike human females who are born with all their eggs fish are able to release all their eggs and then they will have to make more.

I’m going to use for example the zebrafish. Most fish are the same but there may be slight differences ie some have only one ovary most have two. There are other differences but you get the drift I’m not gonna get uber-scientific ill break it down so don’t panic.

How The Eggs Are Made

The process starts with eating yep fatten the female with good foods for all the vitamins and minerals. This will help in the production of cells and hormones. Right now under the zebrafish female’s abdomen between where the belly and tail meet is the urogenital opening (where the eggs will be expelled).

 This opening leads to the two ovaries zebrafish ovaries are usually yellow. the ovary is pretty big and takes up most of the underside of the abdomen. There appear to be 4 main stages of growth for these eggs.

First follicular cells are sent to the ovaries along with germ cells this is the basics of the nucleolus the building of the egg structure. Next, the cells form the periphery which forms the surface and the shape of the egg.

While this happens an opening is also formed and the third stage starts to happen. This third stage is the yolk being produced and entering via the opening. this happens for quite some time as more yolk is forced into the egg.

Finally, layers are made and the outer egg thickens ie a shell is formed and a special tiny hole is also formed for sperm to penetrate and fertilize the eggs.

More Great Articles

What Do Fish Eggs Look Like? 23 Species Of Egg Examined

What Do Neon Tetra Eat? 27 Foods for healthy Fish

Do Fish Hibernate What Is Torpor

Do Fish Feel Pain How We Know A Fish Is In Pain

Can Fish Drown? Do You Have Enough Oxygenated Water

How Eggs Are Laid The Spawning Process

Now there are a multitude of ways fish species spawn. Spawning is the laying and fertilization of the eggs themselves. I say that because there are some species of fish that mate and fertilize the eggs internally and then the female lays her eggs.

We are discussing eggs that are released first and then fertilized. Ok there are still a number of ways fish can do this here are a few.

 

Open Layers 

These fish lay their eggs and let them fall anywhere the eggs are not sticky and tend to lay anywhere on the bottom of the substrate. The male then finds and fertilizes them.

Mop Layers 

Now, these fish have sticky eggs and they spawn over plants and shrubs and let the eggs get stuck in those plants and shrubs. This allows the males to find more eggs and fertilize them more efficiently.

Egg Hiders

As the name suggests these fish hide their eggs. There are a number of ways of doing this I have put them here in one group as egg hiders. But some will find a cave or under rocks to lay eggs some will build a nest and lay eggs there. Others will find shells and pebbles or even bury their eggs under the substrate. After fertilizing of course.

Mouthbrooders

These are probably my favorites just because it’s weird. Get this these fish lay their eggs then they pick them up in their mouths and fertilize the eggs then keep the eggs in their mouths until they hatch.

Even this can be done in different ways by different species of fish. Some lay the eggs then both pick up the eggs male and female. Then the male spits them towards the female and she catches them all. Sometimes the male catches them all and passes them to the female.

Sometimes the female picks them all up and the male fertilizes them while in her mouth. There are even a few that the male fertilizes and picks them up and keeps the eggs until they hatch.

A Few Helpful Articles

Low Tech Aquariums What Are They?

How To Buy A Healthy Neon Tetra

The Benefits Of Deeper Substrate Improving The Walstad Method

The Benefits Of Indian Almond Leaves & Leaf Litter For Neon Tetras

Neon Tetra Breeding How Do They Reproduce?

Fish Do Lay Eggs Conclusion

Yes, there are a plethora of different species of fish that lay eggs. Fish spawn eggs in all manner of ways and in a varied amount of eggs too in the weird and wonderful world of fish. So we know now that fish lay eggs we also know they do this in many ways too. 

We even know how they make more eggs as some fish spawn every few weeks and others just once a year fish are weird but that’s why we love them.

I hope you enjoyed the read and feel free to take a look around the site. I’m gonna leave you with some more great articles from the do fish series of posts.

Do Fish Series 

Do Fish Sleep Can We Tell If Fish Are Sleeping

do fish lose scales? lets investigate

Do Fish Cough?

Do Fish Tanks Need A Lid?

Do Fish Have Noses Can Fish Even Smell?

Do Fish Tanks Make Noise?

Do Fish Like Or Need Toys?

Do Fish Have Teeth?