Aggressive Texas Cichlid

Q. I have a male Texas cichlid that was aggressive toward the female Texas cichlid. I removed the male Texas cichlid to another fish aquarium, and now the female Texas cichlid is fine and starting to dig holes in the gravel. Can I now reintroduce the male cichlid? Also, is there anything I can do to prevent the male cichlid from being so aggressive?
Alley Bornstein
Oswego, New York

A. Because of the limited amount of information in your question, let’s assume you only had the pair of Texas cichlids (Herichthys cyanoguttatum) in the aquarium prior to moving the male cichlid. First, it was good that you chose to move the male Texas cichlid rather than the female Texas cichlid – a detail we’ll use to your advantage when planning a reintroduction. However, while it is good news that the female cichlid seems to have recovered, adding the male cichlid back in with her will present some challenges.

In the best-case scenario, the male cichlid was aggressive toward the female cichlid simply because she was not ready to spawn. In cichlids, like most other fish, eggs are relatively expensive and sperm is comparatively cheap – metabolically speaking. So, that means female fish generally take a little longer to get into breeding condition than male fish – simply because there’s more prep work involved. Removing the male cichlid from the aquarium probably did at least two things: It allowed the female cichlid to recover by removing the physical threat, and it also eliminated any competition for food, allowing the female cichlid access to enough nutrition to potentially ripen a batch of eggs. The fact that the female cichlid is digging pits would seem to support that theory. However, it’s often not that simple.

For cichlids to successfully spawn, it takes more than just mature gametes. One of the reasons cichlids have elaborate courtship behavior (to a greater or lesser degree) is to synchronize their reproductive cycles so that both eggs and sperm are ready at the same time. Unfortunately, conflict arises when reproductive cycles are not synchronized, and it’s particularly problematic in an aquarium where the number of potentially suitable partners is often quite limited. In the wild, the male cichlid would simply chase the unreceptive female cichlid from his territory and wait for another, preferably more suitable mate to swim by.

That’s the second concern with reintroducing the male cichlid. Regardless of their condition, the cichlids will require some time to get their reproductive cycles synchronized, and that’s the time the female cichlid will once again be potentially vulnerable. One of the best ways to safely reintroduce the male cichlid is to place a temporary transparent divider in the aquarium and keep them physically separated until it seems as if they’ve bonded. If the divider method works, you should notice a change in the male cichlid’s behavior from aggressive – indicated by frontal assaults on the divider directly in front of the female cichlid – to courtship, indicated by lateral displays and branchiostegal ray flaring, commonly referred to as gill-flaring. I would suggest, however, that despite how lovingly the male cichlid looks on his side of the divider, that you be present and observe the interactions for a little while after you remove the divider. Male cichlids cannot always be trusted to treat their intended spouses with the respect and admiration we think they should.

If spawning is not immediately in the cards, adding the male cichlid back will require additional tricks. As I mentioned, it was good that you removed the aggressive male Texas cichlid. By doing so, you inadvertently gave the territorial advantage to the female cichlid (the home field advantage, so to speak). However, cichlids can be remarkably bright, and it is likely that your male cichlid will remember both the female cichlid and the layout of the aquarium. While there’s not much you can do about the female cichlid and her history of being the subordinate fish in the relationship, you can change the layout of the aquarium. Re-aquascape your aquarium and then give the female cichlid a few weeks to adjust to the change and establish herself – this will put the male cichlid at a disadvantage when you add him back to the aquarium if he considers it unfamiliar territory.

Lastly, there is absolutely no guarantee that the male cichlid will live peaceably with the female cichlid under your current conditions. Other options include a larger aquarium (limited space is almost always the reason that a subordinate fish gets beaten up by one more dominant), add more fish to the aquarium in an effort to distract the male cichlid and enforce the pair bond, or insert a permanent divider with the male cichlid on one side and the female cichlid on the other. In some cases, once relationships have been established, it is impossible to house the fish in question together, and a permanent divider becomes the only practical solution. Good luck!