Dither fish and target fish

Small tetras usually make ideal dither fish.

Dither fish

Dither fish are used to reassure any nervous fish that would otherwise hide away. Different fish can be used to suit different situations, There is no chance of any fish breeding if it is stressed and in hiding.
Selecting a dither fish is not too problematic if you follow a few simple guidelines. Obviously the dither fish must not be aggressive or a fin nipper nor should it be a hyperactive one that dashes around all the time. A calm peaceful mid-water fish is what we really want. It must also come from a similar environment, temp ph etc.

Once the nervous individuals see the dither fish are swimming out in the open and coming to no harm, They must realise that there there are no predators around and gradually they will calm down. Once settled it is amazing just how ‘tame’ they can become.
When I bought my Discus they were about dare I say it) 3". I introduced them to their tank, They went right into hiding, So much so that the tank appeared fishless, The only thing that would tempt them out was blood worms, And only if I kept perfectly still, If they saw me move they would panic and hide again, for hours. I had intended to keep it as a Discus only tank, but after 3 weeks and my growing concern about the amount of food they were getting I decided to introduce some other dither) fish. So I introduced a shoal of cardinal tetras 24) and 6 Brochis Catfish. Both of these were chosen because of the environmental factors I mentioned earlier.

Within 3days the discus were out and about, 1 month later I could feed them by hand, And now if I put my hands in the tank they come and have a nibble, looking for food.
Best of all, Two pairs have formed and breed on a regular basis. At 7" a male Discus has no problem defending his fry against tetras and catfish.

Target Fish

Sometimes despite all your efforts a pair of fish will refuse to breed. Even when you have prepared the tank perfectly, Used healthy vigorous fish, But still nothing. If the fish concerned are territorial, Then the use of a dither fish could really help.

A dither fish is something that the territorial fish will see as competition, So he will show more interest in "his" females and His territory and generally it will snap him out of his to comfortable life style. The method has proved a success on many occasions.
A good dither fish as I said before will be a perceived threat. It must not be a real threat. E.g. when I bred some small shell dwelling cichlids, I used some zebra Danios as dither fish, The cichlids are bottom living and quite clumsy swimmers, While the Danios are fast moving surface swimmers. So neither fish posed any real threat to the other, But the male cichlid still kept a very close eye on his lady friend just in case.
I must stress please make sure that the choice you make is a good one where nothing gets hurt

In the case of large aggressive South American cichlids such as the jaguar cichlid, Where any dither fish would be in mortal danger, a simple solution is to place a dither fish in another tank next to the potential couple, So that they can be seen but not touched. This does work and obviously no fish can be harmed. You will still have to monitor the situation though because occasionally a fish can become so obsessed with trying to get rid of a rival that he ignores his intended partner which defeats the whole object of the exercise.

A final note in case you were worried that the Danios could feel some stress about sharing their tank with a territorial cichlid, Well I don’t think so, because they also bred… Even before the cichlids.

General rules

Choose carefully, make sure that the target or dither fish that you select is the best one for the job so that none of the fish end up being stressed or harmed in any way.

Try to match fish which live in similar conditions, with the vast majority of aquarium bred fish this won't be a problem as they are generally quite adaptable so long as extremes are avoided.

Don't use fast moving or large fish as dither fish, it won't work. Use slow, small and peaceful fish which are quite bold and not easily spooked.