Skip to Content

Why do Angelfish Lock Lips: Do They Actually Kiss?

Disclosure: When you purchase something through my affiliate links, I earn a small commission. As an Amazon Associate, I earn from qualifying purchases.

Countless times I saw in my aquarium two angelfish do what seemed to be kissing. At first, I thought it was a random behavior. However, I noticed that they do it quite frequently. That was when I began to research why do angelfish lock lips and what it might be indicating. Frankly, what I found quite surprised me.

Angelfish lock lips as part of pairing and mating interaction. Following that, the male and female will seek for a spawning site to breed. On the other hand, lip-locking could be a sign of aggression. That primarily happens as a result of dominance establishment and courtship rejection.

Distinguishing between the two options could be difficult. However, I’ve gathered you a few useful signs to understand the phenomenon in your particular tank better. Also, as you will see later on, there are valuable solutions in case your angelfish are aggressive to each other. 

What Makes Angelfish Lock Lips?

The answer to this question is somewhat complicated. Do angelfish actually kiss? No, not in the conventional human way. But there can be a romantic aspect to it. In an ideal situation, the locking of lips among angelfish will happen when two fish are pairing off for mating purposes. 

But, as was mentioned above, things are sometimes more complicated than that. If you have encountered this behavior for the first time as an amateur breeder, it could also mean the following:

Fish will also lock lips out of aggression, which can manifest between angelfish of any gender.[1] It isn’t that uncommon to find males and females fighting, or even females and females. The factors driving this aggression will vary.

If a female rejects a male’s advances, the male fish can refuse to leave. Doing so will lead to an aggressive confrontation. The male tends to take the majority of the battering in such situations. Every so often, this confrontation will result in the locking of lips.

Some people think that angelfish mate for life. But this is not true. If angelfish pair off and their mating produces young ones, one of the parents can choose to seek another mate later on, especially after a few spawns. The reasons why this happens tend to vary.

Some people have speculated that the fish in question have an evolutionary drive to keep the gene pool diverse. Regardless of the reason, one of the fish could take violent action to chase his or her partner away, and that can result in lip-locking. With that last scenario, you don’t have quite as much reason to worry if your fish are in a tank.

Not only does the abandoned angelfish have nowhere else to go, but, in many cases, the aggressor will find that there are no suitable partners with which it can pursue a mating partnership. The chances that it will eventually resume its collaboration with the first angelfish are pretty high.

What Causes Aggression Among Angelfish?

If your fish are locking lips out of aggression, you probably wonder where this hostility comes from. Several reasons might drive your angelfish to act violently towards one another.

Like most animals, angelfish will try to establish a pecking order, especially if the tank is small. It is quite common for the biggest among them to cement their dominance over their smaller counterparts through violence.

This can result in lip-locking. But this is rare. In the face of aggression, most fish are quick to submit, especially if the purpose is to establish a hierarchy. 

Also, angelfish of the same gender will sometimes fight over a potential mate. In such situations, the fish are fierier. They are less likely to back down, which is why lip-locking is more likely. 

Besides, as was mentioned above, a female will attack a male that has refused to leave after courtship rejection. Some males merely take the battering from their female aggressors. They will only turn to lock lips if the assault grows to unacceptable levels.

Also mentioned above is the fact that an angelfish will use violence to chase a partner away if it finally decides to seek out a new mate. 

It should be stated, if it wasn’t clear, that lip-locking is a way for two fish to test one another’s mettle. It is a relatively quick, relatively efficient means of establishing one’s dominance and superiority.

Are Angelfish Naturally Aggressive Creatures?

If your new angelfish are continually fighting, you are naturally going to question your decision to buy them. You are going wonder whether the species is usually violent and if you are not merely better off replacing them with more peaceful creatures. 

The answer to that question will largely depend on the type of angelfish. 

Freshwater angelfish are rarely aggressive. Or at the very least, you rarely see their offensive side. Can they get violent? Definitely, but primarily in situations where they have young ones to protect.[2]

Freshwater angelfish are very caring parents. So you shouldn’t be too surprised to see them taking aggressive action against fish that approach their eggs.

Saltwater fish are not quite as pleasant. It would be an exaggeration to call them savage, but they are definitely more aggressive than their freshwater counterparts. They tend to construct nests that consist of one male and numerous females. 

They are always determined to defend their harems, which is why they won’t hesitate to show aggression towards other males, especially if they are of a similar species. As you might have guessed, saltwater males are more violent than females. 

What does this tell you? Simply put, you need to select the breed of angelfish you introduce to your tank carefully. Otherwise, you are going to encounter a lot more lip-locking than you would like.

How Can You Prevent Lip Locking Among Angelfish?

Aggression in your fish cannot be eliminated, not wholly. But you can take steps to minimize the occurrences of lip-locking, for instance:

You should start by keeping your tanks pure as possible. That is to say, fight the urge to mix too many species of angelfish. This is going to drive them to compete against one another, not only for dominance but also for what they perceive to be limited resources and territory.[3] Angelfish also tend to attack other fish of a similar shape and color, especially the males.

If some of your fish are simply more aggressive than others, take them out of the tank. Give them their own space from where they are less likely to feel the need to fight for territory or establish dominance over their fellow angelfish.

In case a pair of angelfish keep fighting to protect their young ones, separate them. Put them in a space where they can pursue their breeding activities peacefully.

Still, if one or more angelfish are continually coming under attack from dominant fish, taking those dominant fish away won’t solve the problem. Other dominant fish will arise, and the aggression will start anew. Rather than thinning the ranks in your tanks, do the opposite. Add more fish to the tank. This will act as a distraction. 

When Does Lip-Locking Happen For Mating Purposes?

Lip locking among fish isn’t always easy to interpret, especially if it keeps happening again and again. Either the two angelfish are fighting, or the female is testing the male’s strength for courtship purposes. 

The only way to differentiate between the two is to wait and see. If the two angelfish are going to mate, you will eventually see these signs:

First of all, the chances that you are dealing with a mating pair rise once you observe that one of them is a female. Lip locking among fish of the same gender is just aggression. But if you have a male and a female, then you can bank on the fact that they are looking to mate. 

Once the lip-locking begins, you have every reason to be optimistic. To optimize your chances of a successful spawning, you need to ensure that you have the same breed of fish in the tank. Nevertheless, cross-breeding is also possible. 

A mating pair is going to select a nest, a site where they intend to lay and fertilize their eggs. You will see them cleaning it together.

Eventually, the female will begin to swell as her eggs reach maturity.[4] When the time comes, she will deposit them in the nest. From there, it is up to the male to fertilize the eggs and then defend them from potential threats.[5]

The only way to take comfort in the aggressive behavior between your angelfish is to determine that one of them is a female. This tells you that the lip-locking is probably a mating ritual.

But male and female angelfish are so similar that your options for identifying the females are quite limited. They include the following:

  • There is a slight variation in the shape. Male fish have a noticeable crown. If you pay close attention to their heads, you will note that the crown-like feature is more prominent in male fish than it is in the females.[6]
  • Both genders have a tube between the ventral and caudal fin. This tube is thicker in the females than it is in the male fish. But in many cases, you have to wait until your female fish has started spawning to identify this difference.
  • If you don’t have the time to study the tubes on your fish, wait for the female to lay its eggs. Shortly before this happens, she will swell. This will immediately identify her as the female. Take that opportunity to record their gender.
  • Another way to identify genders is to observe their behavior. Of the two genders, male fish are more territorial. You can see this in the way they act towards other male fish. If you observe this behavior, record it.

Rather than playing this guessing game, you are better off buying a breeding pair in the first place. You can ask your fish store retailer to get you a male and female fish at the start. This way, once the lip-locking happens, you don’t have to question it. 


Lip-locking among fish is an interesting phenomenon, especially when it comes to our beautiful angelfish. In the human eye, it may seem like kissing. However, fish are less complicated than that.

They lock lips primarily for mating purposes or aggressive behavior. Distinguishing between the two could be challenging. However, there are a few tricks to understand your community tank better. Make sure that you observe the angelfish long enough, so you get to understand what their real intentions are.