Mouthbrooder is a term used when talking about fish.
Parents care for the eggs/larva/fry by holding them in their mouth, thus protecting them from danger by third party fish.
Which parent performs this task differs from species to species, any combination is possible:
both parents share the eggs - usually for species that show a strong pair binding, i.e. pairs that stick together a whole life
the father holds the eggs
the mother holds the eggs - this is often the case for polygame species
