Gambusia Affinis

[nelsonic]

Considering keeping Gambusia https://en.wikipedia.org/wiki/Mosquitofish
as the fish in our (micro) aquaponics system because their diet consists of zooplankton, small insects and insect larvae, and detritus material.

They are small which means they will cope well in the "personal" aquaponics system.

https://www.olx.pt/animais/q-gambusias

No sellers in Braga, but Coimbra or Aveiro are near enough.

[iteles]

There are a few pet shops in Braga that might have them too.