All species with the freshwater angelfish genus Pterophyllum (P. altum, P. leopoldi, and P. scalare) will lay their eggs in vertical locations.
The eggs attach to the smooth surface the female places them on until the hatched angelfish fry is free-swimming. You might wonder if your favorite fish does this in the wild and if doing so offers any benefit.
Over the years, we have asked the same questions. While there is limited research into angelfish egg-laying preferences, we believe there are natural reasons they do this. You might not see the importance of understanding this at first glance, but exploring why angelfish lay their eggs on vertical surfaces will improve your care of these beautiful cichlids in all stages of their lives.
Some of the things we can share with you include:
- Where your angelfish will place their eggs in the aquarium
- How such a location may help with egg and larval development
- What you can do to help this process
Where Angelfish Lay Their Eggs
Freshwater angelfish lay their eggs on mostly vertical surfaces in their native waters. If you think about it, several types of underwater structures rest in a general up-and-down position in the rivers and tributaries of the Amazon and Orinoco river basins.
Access to these surfaces is not the only factor in play there. The waters in these South American locations are warm and slow-moving. That allows the eggs to remain on a vertical surface more readily than if in swift-moving currents.
In the wild, males have established territories, and those areas become their breeding grounds. That means a gravid female will use the exposed roots, plant leaves, and smooth rock surfaces within the male’s controlled area.
Selecting these locations is instinctual and transfers to fish kept in aquariums, even if they are several generations removed from their natural habitats. Your adult female angelfish will identify the smooth vertical surfaces within the male’s territory in the fish tank to place her eggs. Post fertilization, the pair will protect the location or move the eggs to another vertical spot if needed.
That means you can find angelfish eggs placed on artificial or living plants, tank decor with smooth standing surfaces, vertical aquarium equipment such as the heater, or the tank’s glass walls.
You may find eggs anywhere the breeding pair feel safe if you keep your angelfish in a separate tank. Options will be limited to locations within or adjacent to the male’s pre-established territory within a community aquarium.
Why Do Angelfish Lay Eggs on Vertical Surfaces
There is no place like home when it comes to laying eggs. Freshwater angelfish have a compressed body flattened from the sides, providing agility and speed to maneuver around the obstacles in their natural river basins. Those same obstacles they live between become the convenient egg-bearing surfaces during the spawn.
In the wild, angelfish will find it easier to defend eggs from opportunistic poaching by staying within the roots and plants they call home. Their mouths, which they use to move eggs and wigglers, are shaped for mid and upper-level feeding.
Angelfish will use their fins to help oxygenate the eggs, and vertical locations make this easier than attempting to provide additional oxygen on horizontal surfaces that often exist on the bottom of rivers or your aquarium setup.
Freshwater angelfish parents can also become easily stressed. That can cause them to abandon the eggs or eat them to prevent other fish from benefiting from the meal. Vertical egg-bearing surfaces keep the breeding pair in a natural swimming position and provide better cover by reducing angles of attack from other fish.
In nature, vertical surfaces in dense vegetation also protect the free-swimming fry once they become self-sufficient. Those areas also tend to house the freshly hatched foods juvenile angelfish need to grow. Those factors are critical for development and ensure that some fry can reach adulthood and continue the species.
What Can You Do To Help With Egg-Laying Surfaces
If you have a breeding pair of angelfish or even a lone female, you will likely find eggs in your tank at some point. It is part of the lived experience for adult specimens, but do you need to do anything?
If you are not worried about the eggs, you can leave them. The only time you might consider removing unwanted eggs is to reduce the aggression or stress for your pets, especially in a community aquarium.
On the other hand, if you want to keep as many eggs as possible, you might want to add a temporary egg-laying surface you can remove. The Aqua KT Discuss Fish Breeding Cone is a popular choice that provides a stable surface that is more aesthetic than a plastic sheet.
You can also let your breeding pair care for the eggs by keeping them in the aquarium. Many aquarium enthusiasts, ourselves included, maintain planted tanks that provide more natural egg-laying surfaces. You may also notice that your angelfish can find a less-stressful location for their spawn when compared to a sparse or empty tank.
Artificial or live plants not only offer more seclusion, but they can also help protect fry as they become free swimmers. Remember, your angelfish parents will prepare for the next spawn as soon as possible, so they usually leave the fry to fend for themselves once they are self-sufficient.
Making You a Better Hobbyist
Knowing where your angelfish will lay her eggs is information that will make things easier for you and the adult angelfish in your care. The fish have developed the need to use vertical surfaces over millennia of living in South American river basins among tall broad-leafed plants, exposed roots, and the vertical edges of those waterways.
These locations are ideally suited for the parents, providing naturally defendable positions that can benefit the fry once they are on their own. Your breeding pair will use vertical surfaces within the aquarium as well. You can leave the eggs in place and let the parents raise their young, or use something like the Aqua KT Discuss Fish Breeding Cone so you can remove them to a separate fish tank.
No matter what you do, take the time to enjoy watching your adult angelfish perform this crucial biological task. If you have questions about angelfish egg laying or other concerns, comment below so we can help!