Top 5 Dither Fish to Help Shy or Aggressive Fish

If you have timid or territorial fish in your aquarium, try calming them down with dither fish. Dither fish have outgoing personalities and swim out in the open all the time. Dither fish are confident and show that they don’t fear danger. The presence of large numbers of ditherfish helps to diffuse and distract fish bullies from focusing on one fish. Learn more about the best dither fish that can change the dynamics of your fish tank and give you a more active community aquarium to enjoy.

1. Livebearers

Livebearers are fish that bear live young, and most of the common types at the pet store (e.g., guppies, platies, and mollies) are extremely friendly and colorful. Their eggs are prolific and can be found anywhere they want. These brave livebearers babies are more likely to be seen by skittish fish than any other species.

To break up tension between two angelfish, you can add a few mollies, swordtails or other large livebearers to help them fight. The livebearers will be able to swim around and easily invade their space. The angelfish cannot keep all the dither fish out of their territory, so the hope is that they will give up trying to defend their boundaries. Yes, the angelfish may eat some of the livebearer fry that wander too close, but this helps keep their population under control so that you are not overrun with babies.

Many livebearers exhibit a caring, easygoing disposition that can help semiaggressive species like angelfish relax.

2. Tetras and Rasboras

Both schools of schooling fish are famous for their torpedo-shaped, streamlined bodies. This makes them fast enough to escape any tank boss. Some rasboras and tetras can be wary, as they are usually less than 3 inches in length. They tend to be braver if you increase their school size, so make sure they have at least 6-12 fish from the same species.

You might choose a small schooling fish to help a shy nanofish feel more confident. On the other hand, if you hope to pacify a big and belligerent fish, go with a larger schooling fish that won’t get eaten. These suggestions are categorized according to size depending on your needs:

Rummy nose Tetras are known for being very close-knit schooling fish, which swim in a tight group and then change direction like a huge herd. This behavior can confuse predators since they find it harder to catch one fish when there are a lot of them.

There’s nothing quite like watching a large group of rummy nose tetras swimming in perfect synchronization.

3. Corydoras

While tetras and rasboras often swim in the middle level of the aquarium, cory catfish stay down low near the floor, constantly scavenging for food out in the open. Cory catfish are a great dither fish for bottom dwellers such as Apistogramma or kribensis, who want to know when their babies can come out to feed. Corydoras are great clean-up crew members that do well in a group of 6 or more of their own species, and there are many kinds to choose from. Brochis catfish are larger and more capable of swallowing smaller corys if you have blood parrots or other large fish. You can actually keep corys, livebearers and tetras together in a tank with dither fish.

Albino corydoras are one of the most sociable catfish you can find, and they love eating frozen bloodworms, freeze-dried tubifex worms, and sinking pellets.

4. Danios, Rainbowfish

Sometimes medium- to large-sized predators like Jack Dempsey and oscar cichlids can be uncharacteristically shy and prone to hiding. In those cases, you want bigger, super fast schooling fish like giant danios (Devario aequipinnatus) and hill trouts (Barilius spp.) They are more likely to escape their jaws. By actively darting around at a million miles an hour and breaking into everyone’s territories, these dither fish give off the message that “I’m a smaller fish, yet I find it safe to freely swim out in the open.” If you have a jumpy bala shark that tends to freak out and ram into walls, you can also try dither fish to help it settle down. Rainbowfish are a confident, colorful and calm schooling species that can help calm other more anxious species.

Hill trout are speedy swimmers capable of traveling in fast-flowing streams, so try not to pair them with slower fish who may get outcompeted during mealtimes.

5. Hatchetfish and Pencilfish

What if you have shy fish you want spawn, but don’t want their babies to be eaten by the ditherfish? Look out for fish that live at the top of the aquarium, such as hatchetfish or pencilfish. These surface dwellers mostly swim in the upper third of the aquarium and have tiny, upward facing mouths that prefer eating floating foods from above. This is perfect for ram or Apistogramma dwarf cichlids that are guarding their babies down near the substrate. Pencilfish and hatchetfish are not likely to come down to feed, and they won’t eat fry if they happen to be swimming up on top. When you feed the aquarium, the skittish fish will see the dither fish rushing to grab a bite, so then they will feel more comfortable coming out to feed as well.

Nannostomus eques have a reputation for swimming at 45 degrees to the surface. This is why they are often called the diptail and hockeystick pencilfish.

Dither fish can bring out the best behavior in your aquarium by coaxing fish out of hiding, putting the tank bosses at ease, and increasing the activity level overall. You can find fun fish at our store in Edmunds, Washington, or our top online fish sellers.