How to know if fish eggs are fertilized? This is something you are going to need to have a good understanding of if you want to keep fish.
Why do I say this? Well, the eggs that fish carry can if left and they don’t indeed hatch. Can become toxic to our little fish friends. Those eggs can start to decay rapidly and get all kinds of fungus on them.
Lucky for you and all of us there are some tell tail signs of telling fertile and unfertilized eggs apart. I’m going to give you 9 awesome ways of doing this.
First ill give you a quick synopsis of what to look out for and how to tell if the egg has been fertilized. Then id like to go deeper and showcase those (9) amazing ways of telling a fertilized fish egg. Let’s go.
How To Know If Fish Eggs Are Fertilized
How to know if fish eggs are fertilized looking at the egg it will change color and grow slightly as well as an egg spot appearing. After a few days, you will see 2 black dots these are the eyes of the embryo.
Brief Fish Egg Description
Here id like to give a brief outline of what fish eggs should look like. Although there’s quite a distinct difference in some eggs as there are some 33,000 species of fish.
You can have a look at an article I’ve written for a more in-depth look at what fish eggs look like What Do Fish Eggs Look Like? 23 Species Of Egg ExaminedPlease feel free to have a read.
Most eggs are rounded oval or ball-shaped. They can appear to be like gravel or even small bubbles you may find them in plants shrubs and other flora. Although some will be over the substrate or even stuck to the glass.
They will do all those things fertilized or not we need to tell if they are fertilized. What’s the big thing about telling the difference between fertilized and unfertilized eggs?
Why We Shouldn’t Leave Unfertilized Fish Eggs In Our Tanks
The problem is that if these fish eggs are unfertilized and left in the tank the water will be affected. As these eggs will decompose leaving toxins in the water that can harm other aquatic life.
Also if left these little eggs can spike ammonia. and that is a no-no as we all know as ammonia poisoning will definitely harm or even kill our fish. Have a look at another awesome article I wrote on ammonia and how it can burn fish. And if they can recover from ammonia poisoning.
Another big problem and a good reason to remove the eggs. Fungus will develop on unfertilized eggs and start to cause problems in the tank.
Let’s help identify fish eggs that have been fertilized.
Milt/Sperm
That’s correct when those eggs were laid you may have seen the water get cloudy. Mainly over plants shrubs and other flora.
If the water gets a bit foggy milky this could well be the male spraying his milt/sperm over the eggs.in order to fertilize them.
Slight Growth In Eggs
As with all life, it needs to grow. So if the egg has been fertilized you can expect to see some real growth with the eggs themselves. This growth will happen pretty quickly as most eggs don’t take that long to hatch. I have an article on the length of time for a number of fish species How long do fish eggs take to hatch feel free to have butchers.
Even on the first day, they will grow. So you will start to see a difference between fertilized and unfertilized eggs.
Color Change In Eggs
If the fish egg has been fertilized one of the first things you will notice. Along with growth is that the egg will change color. Most eggs not all but most will start clear or white and then start to darken. Becoming more yellow, brown, or orange.
This tends to happen after the first day although neon tetra eggs hatch after 24 hours so they change color in just hours so be vigilant. how neon tetra reproduces here is more on the neon tetra egg hope you enjoy the read.
Most eggs will take a bit longer but nonetheless will change color.
Egg Spot
Fairly soon after the eggs have been fertilized. You will notice the eggs have developed a distinct spot on them. Now again as a caveat, this may not happen to all species of fish eggs. But most fish eggs will have a grey or black spot appear.
This spot is kind of like confirmation that the eggs are good and have been processed and fertilized.
Two Black Dots
Next not to be confused with the spot that appears. Two black spots will appear now these are on the inside of the egg.
As the egg is semi-transparent we can see inside and peering out are two black spots these are the eyes of the baby fish. the baby fry.
Seeing The Embryo
Now it gets more interesting as we can see the egg develop. The egg has gotten bigger the color has changed the spot has appeared and we can see the eyes.
Now we can actually see the embryo we can see the baby fry inside the egg growing and getting stronger by the hour. If you are lucky you will now start to see the baby fry moving.
Fungal Build Up
As alluded to earlier if they start to get funky and fungus starts to appear then those eggs are deffo not fertilized and you need to get rid of them asap. As this can unbalance the ph and water conditions as well as the build-up of toxins and ammonia. Click the links for more info on water parameters and ph levels
Parental Care For Eggs
Now not all fish care for their young far from it most don’t take any parental responsibility. For those that do. They will look after those eggs like their very life depends on it.
Nest builders and bubble nest builders as well as those that hide their eggs. Only look after fertilized eggs they throw out the unfertilized eggs. Or they eat them in some cases. Click above on bubble nest builders to discover more.
So if you have fish that tend to their young. They will be fertilized eggs that they are looking after.
The Eggs Hatched
Now fish can lay or sawn as it’s called. They can spawn a load of eggs anywhere from 30 to 500 eggs in a normal home tank. Those eggs that are fertilized will hatch most hatch between 1 and 4 days after being laid.
Have a look at these links to learn more about hatching times and the number of eggs that fish generally lay.
Obviously, if the eggs hatched then they were fertilized. Any eggs left can be gotten rid of.
How To Get Rid Of Unfertile Fish Eggs Safely
Once we are sure that we have infertile eggs if the other fish or aquatic life haven’t eaten them. We can gently siphon and vacuum the substrate and all-around plants shrubs and other flora.
Keep an eye out for any stay eggs but to be honest the other fish will probably eat those too.
How To Know If Fish Eggs Are Fertilized The Conclusion
Hopefully, we now have some extra knowledge. We can now determine a fertile fish egg from an infertile or unfertilized fish egg. Something to bear in mind is how long fish carry eggs. I’ve got a great resource for that here How Long Do Fish Stay Pregnant (5) Great Ways (33,000) Species Of Fish.
This is important because if you know how long your particular species carries for the easier for you to work out if they have laid eggs.
It’s also important to point out that most eggs don’t survive they are either infertile unfertilized or eaten before they have a chance to hatch.
For more on this check, out this little article Fish Eggs In Tank Can They Survive (90) % Will Die and if you want more info on if your fish is mating then I’ve got you covered here How Do Fish Mate 1 Free & Easy 2 Forever.
As always I hope you enjoyed the read and please feel free to look around the site for great articles tips and tricks. I’d also like to leave you with some posts from the do fish series of articles.
Do Fish Series
Do Fish Hibernate What Is Torpor
Do Fish Feel Pain How We Know A Fish Is In Pain
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