How Do I Know if My Fish Are Mating or Fighting?

Similar to many other species in the animal kingdom, fish sometimes fight for various reasons. Whether these reasons involve natural aggression, territorial behavior, or competitive feeding, asserting dominance is the common denominator and the end result. In some cases, the fighting will be motivated by mating cycles whereby males compete for the attention of females. Unless you’re a marine biologist, you may conflate further steps of mating with fighting because the behaviors look almost the same, and they may also vary between species. Seasoned fish keepers who breed their own stock, as well as the individuals who work at your trusted aquarium supplier, can differentiate between the two behaviors, and this is what they can tell us.

Early Signs of Mating

Some species pair off and separate from their groups on their own and without any noticeable aggression. In this case, there’s no fighting at all, and the flirting signs aren’t obvious because males will vibrate their bodies when they sense a fertile female, but this isn’t easy to spot. Gregarious reef tank species such as parrot fish exhibit kissing behavior that’s flirtatious but which may attract the attention of competitive males. However, the female parrot fish generally chooses her mate before fights ensue.

Energetic Mating Behavior

Smarter species such as Oscar fish have a more elaborate mating ritual whereby the female likes to be chased around the tank. If the female Oscar plays hard to get, the suitor will become more physical with rubbing behavior that may look like fighting when it isn’t. Oscar couples always get along even when they’re not mating, so if you spot aggressive behavior and chasing, you’ll know they’re actually mating. Keeping more than one male Oscar in a tank isn’t recommended because they’ll likely fight for the attention of females every mating season. Silver dollars are even more energetic when chasing females, but you won’t see biting.

Koi Mating Behavior

The size of koi and their somewhat unusual mating behavior looks a lot like fighting. Females carrying eggs won’t release them unless their pond mates help them do so, and this requires vigorous bumping of the abdominal section. Koi males that aren’t the chosen partner will join in this behavior, and even other females that haven’t been inseminated may participate. This behavior invariably occurs during the spring.

Defending the Nest

When mating is done and females lay eggs, they’ll switch to a defensive mode that lasts until spawning. Once again, the smarter species such as Oscars and parrots will work as couples to defend the nest. Females of most other species will do so on their own, and they may become very aggressive with their protection. In a community tank where fish are happy with their feeding, they may not go after eggs, thus reducing the risk of fighting. However, it’s always best to have some bushy real or synthetic plants for the fry to hide in.

No matter the behaviors of your fish, you need to make sure you have all of the necessary supplies on hand to keep them happy and healthy. Whether you need an aquarium temperature controller, a filtration system, beneficial bacteria, testing kits, or any other aquarium supply, Aquatic Warehouse has got you covered. Stop by our store in Kearny Mesa, shop for what you need on our website, or give us a call today with any questions at 858-467-9297.