The unfortunate (or not) dither fish

[GaryE]

I read that there are two reasons to employ dithers. First, to show the cichlids that there is nothing to fear in the higher levels of the water column. They can come out and play. Second, to be a distraction so that cichlids aggression is directed at the fast swimming dithers and away from conspecifics.

Both are good reasons in a tank that prioritizes Cichlids.

They can also be chosen to bring very shy fish out into the light. A shoal of a fearless tetras can be 'hired' to make Corys be more out and about, to bring nervous tetras around, to acclimate nervous fish to tank life...

There's the old basic. If we're bottom dwelling fish used to life in the shaded sections of our environment, but we see a shoal swimming above us, we have to think about that. If it's never attacked by birds or predators, then maybe the habitat is safer than we're used to. It attacks food fearlessly. Why can't we? There is a mentoring aspect. Fish with complex behaviour show us they learn, and not just from their own species. When wild caught fish or even tank raised fish encounter food in a new format, they'll often go for it after they see a tankmate try it. It's funny - farm raised fish are often paralyzed the first time they see live food, while wild caughts stop dead at the sight of flake. Instinct says to eat, but experience gets in the way for a moment.

When I employ the 'dithers' this way, it's important that they be similar to the fish I'm hoping to bring out. You aren't likely to get a tetra to relax around a molly - they are too different. But a tetra, or even an Asian Rasbora type can be useful. The goal is to see our fish in good colour acting relatively normally even if all tanks are abnormal habitats. Some small fish are just too shy by nature, but most adjust with a few mentors and a smart layout.

How does the shoal become fearless? In this case, they are tank bred, and have only lived here. They've adjusted to life with my lights, my feeding, my mug staring at them. Their instincts are still there, but the Pristella I'm employing are silvery, which says they use the reflection of sun on water as camouflage. I wouldn't use my home bred cardinals in this role.

 

[Magnum Man]

I just don't like the "dither fish" name and what it implies... I prefer to make a tank a community of fish that I want to see together... I understand the job, is real and often needed... I guess I'm saying I wouldn't choose a fish just for the job, but I have chosen fish I actually have interest in, for the job, so I care about the well being of all my fish... exception to that is of course feeders... and I'm sure if I were breeding Rosy minnows, I'd have to stop feeding them, or I'd have my favorites, that I wouldn't intentionally feed.... which could be done, as I have my bichir eating pellets now... so I'm sure I could get it switched over to frozen small size shrimp from grocery store, with most all the benefits of live feeding, and less risk... but really circle of life is what it is, weather you feed a pellet that contains lots other dead animals... and the animal has a real hunting and killing instinct... this bichir will kill all the feeders added, the 1st night they are added to the tank, even if it can't eat anymore, and leaves their mangled bodies floating around the tank, to eat later... the silver dollars in this tank, aren't dithers... I just hoped the size and shape, would make them appear un edible... and that and the speed and wariness seems to be working... it did not work for the common pleco, that was 3/4 the size of the bichir, which it promptly ate...

 

[WhistlingBadger]

"Dither". It's a good question. When I first heard of the technique, they were called "target fish". In how I'm using it - no one gets targeted. They're confidence builders.

"to dither" is to act nervously or indecisively, so as a verb, it isn't a great fit. To be in a dither is to be wound up. That's not ideal either. Maybe there's a regional meaning I haven't heard but that makes more sense to someone who has.

So really, we should call them anti-dither fish. But that's too hard to say. Duck hunters use something called "confidence decoys." They'll put a few fake crows, a great blue heron, or even a deer near their duck decoy spread, so pressured ducks think everything is OK. Such critters are smart, spooky and disinclined to stick around if those pesky humans are in the area; the ducks seem to know this.

So maybe we should quit calling them dither fish and start calling them confidence decoys.

 

[gwand]

That never fooled Daffy or Donald Duck!

 

[GaryE]

Confidence decoys. It doesn't work for the traditional Cichlid "target fish", but it would work for fish used to draw others out.

 

[seangee]

I've only used them for confidence. I had a group of 12 ambastaia sidthimunki in a 20G tank. I hardly ever saw them. IIRC it was @Byron who gave me the idea of adding 20ish microdevario kubotai as dither fish (I just took everything the LFS had ). It turned out a great combination and I could keep it as a Thai themed tank. The sids completely ignored the little green flashes, but were out and about all the time.

 

[TwoTankAmin]

My water is not good for rifties. So I pretty much do softer water fish. I kept a lot of plecos as well as corys. For me a dither is an upper water swimmer in a tank. It is not a threat to anything. Its purpose is to make the non predatory bottom dwellers know it is safe to come out. If they peek out of hiding and do not see the smaller schoolers or loosely grouping fish that means there must be something threatening/dangerous up there.

But if the smaller fish are out and about that means it is probably safe to come out. Basically, bottom dwellers have upward facing eyes (and downward facing mouths). So they take their cues from what is going on above.

I always thought the way to blunt aggression in many of the the African cichlids was by having a lot of them. Having many means no one or two fish should be picked on. The numbers act to spread aggression. Am I wrong in my understanding here?

I rarely do species tanks unless I am working to breed that species.

I have kept fish that cost me under a dollar and fish that cost me 4 figures. I treat them all the same. I will spend as much time and money trying to cure a sick tetra as I will a zebra pleco or an even pricier species. The minute I put a fish into a tank it becomes my responsibility to give the best care I can. This also includes what I will feed it, how the space is set-up and which tank mates it might have.