One goldfish chasing the other

[reindeer_floatilla]

My black moor keeps chasing my pearlscale around the tank, sometimes pushing it over or into plants...
I understand this is goldfish mating behavior, but it's been happening for around 10 days (not all the time, but a few times an hour at least)
My friend suggested that the black moor thinks the pearlscale is pregnant due to its rotundity, when it really isn't, but I'm not very familiar with goldfish mating to know if this is a possibility.
The water parameters are fine, and both fish are tiny (only around 5cm, the pearlscale is smaller)
If there's anything I could do, please let me know!

 

[foxgirl158]

How big is the tank?

 

[reindeer_floatilla]

I think it's around 55 litres
I know this isn't a permanent housing solution for them, but they are both still very small, and I will relocate them to my pond when they outgrow their tank

 

[Colin_T]

Can you post pictures of the fish?

Did the water temperature increase a couple of weeks ago?
If yes, it might have stimuated the fish and brought them into breeding condition.

Check the black moor for white dots on the gill covers and edge of the pectoral (side) fins. If there are white dots then the fish is a male in breeding condition. Female goldfish do not have the white dots.

If the pearlscale is getting harassed, separate them so the male doesn't injure her.

If you have fantail goldfish outdoors, make sure the pond is well covered to stop birds and other animals getting the fish. Fantail goldfish are slower moving due to their double tail, and fish like pearlscales are slower again due to their body shape. These fish make easy pickings for birds, cats and other predators.