Size, Lifespan, Diet & More


The scissortail rasbora is a fun freshwater species to own, and is a great choice for many aquarists. As long as you’re willing to give them some attention and set up an adequate tank, these fish will thrive.

This guide will go over everything you should know about scissortail rasbora care. Their size, lifespan, diet, tank mates, and tank size are all covered!

Species Summary

The scissortail rasbora (Rasbora trilineata) is an eye-catching freshwater fish species known for its distinct fin shape. At first glance, this fish looks like your average shiner or minnow. But close examination unveils beautiful color patterns and some unique swimming behaviors.

Scissortail rasboras swimming in a tank

The rasbora goes by a few different names. Most of the fish in the pet trade are captive-bred, and you might see them called everything from the “black scissortail” to the “three-lined rasbora.” Whatever name it holds at your local fish supplier, the scissortail rasbora is a unique fish to own and care for.

It’s native to slow-moving rivers in Southeast Asia. More specifically, they’re predominantly found in the Mekong River Basin in Laos, Thailand, and Cambodia. Slow and easy rivers are where the fish live most, but they’re also found in fast-moving streams and lakes. 

The scissortail rasbora is a compelling freshwater fish species. Relatively easy to keep healthy, they can make lively additions to your tank.


Most of the scissortail rasbora’s body is silver and iridescent. In the proper lighting, the scales create a beautiful shimmer you can’t help but appreciate. The body is sleek and slender, taking on a dart-like silhouette perfect for zipping through the water.

Running from behind the gills to the tail is a subtle black line. It accentuates the unique forked tail. Most fish have a forked caudal fin, but the scissortail rasbora’s fin is deep. 

It starts as transparent, but the tips of both forks feature thick banded stripes of yellow, black, and white. This is one of the most noteworthy features of the fish.


The average scissortail rasbora lifespan is roughly five years. However, some scissortail rasboras can live for as long as seven years in the right conditions.

There’s no way to guarantee how long these fish will live. Genetics plays a part in the fish’s longevity, and the same goes for the level of care you provide. As you would expect, fish in substandard living conditions can succumb to disease and premature death.

Average Size

The average scissortail rasbora size is usually around three and a half inches in length. Most are smaller when you buy them at a fish nursery, but they quickly reach that size with proper care.

Author Note: It’s worth noting that some aquarists will see their fish get even bigger. It’s not uncommon for a full-grown scissortail rasbora to reach lengths of around six inches with a healthy diet and optimal care.

Scissortail Rasbora Care

Scissortail rasbora care isn’t too difficult for most aquarists. They’re considered beginner-friendly and don’t have too many unique challenges to overcome.

If you stick to the following care guidelines, your scissortail rasbora should live a happy and healthy life.

Tank Size

Scissortail rasboras need ample room to swim around, but they’re not so big that you must invest in a massive tank.

Most aquarists agree that 20 gallons is the smallest tank size you should consider for scissortail rasboras. However, a 30-gallon aquarium is even better if you have room for it.

Author Note: Those tank sizes can support a small group of six fish. If your scissortail rasboras grow larger than average, it may be worth investing in a bigger aquarium to accommodate their active lifestyles.

These fish are strong swimmers, so they do best in horizontally oriented tanks. They reside in the upper and middle parts of the water column and spend most of their day zipping back and forth. While taller tanks are suitable, a longer tank with more swimming space is always better.

Water Parameters

Like any other fish species, the best course of action when setting up a tank is to replicate the water conditions from their natural habitat. These fish come from rivers, streams, and lakes in Southeast Asia. The waters are tropical in nature, making things a little easier for aquarists like you.

Scissortail rasboras thrive in most standard water conditions. As a result, they do well in multi-species community tanks with basic water parameters. While adaptable to some extent, stability is the most important thing.

It’s crucial to monitor water conditions and avoid any significant fluctuations. Otherwise, you could create a stress-inducing environment for your fish.

  • Water temperature: 73 to 78 degrees Fahrenheit
  • pH levels: 6.0 to 7.0 (Around 6.6 is ideal)
  • Water hardness: 2 to 12 dGH

Setting Up The Inside Of Their Tank

Scissortail rasboras are pretty adaptable when it comes to decor. They’re not fussy, but there are a few things you must ensure to include.

The first is creating an open swimming space. Over-stuffed tanks aren’t great for scissortail rasboras. They need room to roam and plenty to flex their swimming abilities.

The good news is that you can focus your decor on the lower parts of the tank and its perimeter. These fish rarely venture to the bottom but appreciate some hiding places to explore.

The best type of decor mimics the riverbeds of their natural habitat. Items like driftwood and rocks are all excellent choices. For the substrate, choose a dark-colored material like black sand.

Scissortail rasboras appreciate having soft plants to swim through. However, they should be sporadically placed around the tank’s perimeter to maintain that open swimming area. Any delicate and soft plants will work. 

This fish species particularly enjoys java moss. You can also add peat or Indian almond leaves to add some tannins to the water. Though, it’s not required.

Subdued lighting is best for scissortail rasboras. While they prefer soft lighting, they adapt well to most conditions. This species does well in an aquarium with other community-friendly fish, so it’s fine to have stronger lights if that’s what other species in the aquarium prefer.

As for equipment, there are a couple of must-haves. First, make sure to have a subtle current. You can create one with a water pump or use the outlet of your filtration system.

The current doesn’t have to be strong. These fish usually live in slow-moving rivers. However, they enjoy having some movement.

Author Note: Don’t forget to invest in a tight-fitting lid! Scissortail rasboras are prone to leaping out of tanks if there’s nothing to prevent them from doing so.

Common Possible Diseases

Scissortail rasboras aren’t prone to any genetic diseases or major health conditions. That’s the good news. However, these fish can suffer from all the usual health problems that can impact freshwater fish in poor conditions.

If these fish don’t get the quality care they need, they can suffer from Ich, fungal infections, bacterial infections, and more.

Healthy Rasbora trilineata in a freshwater aquarium

Ich, also known as white spot disease, is the product of stress. It usually affects fish that are living in dirty tanks. Ich also takes hold when water parameters suddenly fluctuate.

The disease causes white spots to develop all over the body. It’s highly contagious and can spread to other fish in the same aquarium. If left untreated, it can lead to death.

Luckily, it’s pretty easy to treat with copper-based medicines.

Scissortail rasboras can also get something called fin rot, a bacterial disease that eats away at that signature striped tail. Usually, fin rot occurs when the fish is eating a poor diet. Overcrowded tanks with lackluster water conditions can cause it, too.

Vets typically prescribe fish-safe antibiotics to kill the bacteria and encourage healing.

Finally, scissortail rasboras can suffer from fungal infections. When that happens, the body might develop large white patches, dulling color, and a coat of gray slime over the scales.

This health issue is, once again, caused by poor water conditions. To treat fungal infections, you must quarantine the affected fish, raise the temperature to kill any fungi, and provide proper medication.

Food & Diet

Scissortail rasboras won’t shy away from food. They accept most commercial dried fish foods without any problems. Flakes and pellets are easy to source and can make feeding much more straightforward.

Choose a well-balanced formula. Those formulated for intense coloration can bring out the unique striped detail on the fin.

Whenever possible, provide live, frozen, or freeze-dried foods. In the wild, the fish’s diet consists mainly of insects. Giving them these foods will not only provide valuable nutrition, but enrichment as well.

They will excitedly eat everything from brine shrimp and daphnia to bloodworms and mosquito larvae.

Author Note: This species needs a lot of food to stay healthy. Most fish experts recommend feeding the fish three times a day. Provide enough food that they can consume in three minutes.

If leftover morsels are in the tank after three minutes, do your best to remove them and adjust your feeding portions. Leftover food can quickly sour water conditions, so avoiding overfeeding is essential.

Behavior & Temperament

Scissortail rasboras are passive fish. They’re usually pretty peaceful and get along with most freshwater species. They will try to defend themselves if another aggressor causes trouble, but these fish rarely start fights on their own.

They’re a curious and playful species. You can observe scissortail rasboras zipping back and forth through the open swimming space to get their exercise. Then, they’ll explore plants and decor to pass the time.

In the wild, scissortail rasboras are schooling fish. They live in massive groups and often move as units. 

In a home aquarium, they aren’t as reliant on large groups. But they need to have others in the same space to stay healthy. Keeping at least half a dozen fish together is the best practice for this species.

In a small group, scissortail rasboras are more confident. They will swim around together, exploring the area without fear. Without a group, they can become anxious and disease-ridden.

Author Note: This fish species is easy to startle, so be wary when opening the tank lid. They’ll often jump out of the water when caught by surprise.

Scissortail Rasbora Tank Mates

Next to a small group of their own, there are many great scissortail rasbora tank mates to consider. These fish can cohabitate peacefully with other like-minded species. Simply avoid any fish that’s too large or aggressive.

They might be fast, but these fish can still become fish food for large aggressors. It’s also a good idea to steer clear of fin-nippers.

The best tank mates for the scissortail rasbora include:


Breeding scissortail rasboras isn’t too difficult. However, it does require some prep work.

Start by setting up your breeding tank.

Scissortail rasboras are egg scatters. The females swim around the tank, depositing the eggs as if she’s spreading confetti! To maximize egg survival, equip the bottom half of the tank with mesh. You can also use spawning mats.

The mesh and mats will protect the eggs and prevent the adults from gobbling them up.

For water conditions, raise the temperature to 77 to 82 degrees Fahrenheit. Keep the lighting low and alter the pH balance for slight acidity.

Next, you’ll need to identify the females. They’re typically plumper than the males. They have more rounded bodies instead of that super-sleek profile.

Condition the males and females with protein-rich food. Provide plenty of bloodworms, brine shrimp, daphnia, and other high-quality foods. Doing so will prepare them for spawning and trigger egg development in the female.

Continue providing those foods until spawning occurs. After the female lays the eggs, remove the adults. The eggs are sensitive to fungal problems, so it’s wise to perform frequent water changes and use antifungal treatments.

You will only have to do that for a short time. Eggs hatch in about 24 hours. After that, the fry feed on the egg sac for two days.

When the young fish become free-swimming, you can offer powdered fish food and baby brine shrimp.


We hope this guide about scissortail rasbora care was helpful, and makes you feel more confident in purchasing some for yourself!

If you ever have any questions about this species and want some extra help, let us know. We’re more than happy to give you a hand.


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