How do you tell if a pair of sucker fish are being aggressive to one another and what sex they are?

* Chasing or nipping at each other

* Displaying their fins or barbels

* Bumping into each other forcefully

* Circling each other

* One fish hiding or avoiding the other

Determining the sex of sucker fish:

* Body shape: Males are typically longer and thinner than females.

* Genital papilla: Males have a pointed genital papilla, while females have a rounded one.

* Spawning marks: During spawning season, females may develop small bumps or tubercles on their heads and bellies.

If you notice any signs of aggression between your sucker fish, it is important to take action to separate them. This can be done by providing them with separate hiding spots or by adding a divider to their tank. In some cases, it may be necessary to rehome one of the fish.