Ultimate Care Guide for Roseline Shark

Most aquarists, if not all, are always after some fun and beauty when choosing an ideal tank addition. So far, only a few species can beat the Roseline shark in being the perfect fish to keep at home.

Hailing from the fast-moving waters in Western India, the fish stands out due to its intense coloration that can light up any environment. They are easy to keep and get along well with several other species.

However, you must give the species a perfect environment to ensure a healthy and calm fish. Here’s everything you need to know about how to care for the Roseline shark.

Scientific Classification

Scientific name: Sahyadra denisonii
Common names: Denison Barb, Red-Line Torpedo Barb, Miss Kerala, Chorai Kanni
Genus: Sahyadria
Family: Cyprinidae

History and the First Sighting

The Roseline shark was discovered as early as 1865 but became popular later. It was introduced to aquariums in the 1990s, becoming an instant classic. Despite the fact that it was primarily collected from its natural habitat, the uplands streams of southwestern India, it has since become a staple in aquaculture.

In 1996, the fish had a massive collection and exportation run, which earned it second place at Aquarama 1997. Ever since it has grown in popularity in the aquarium trade. The fish currently make up 60 to 65% of ornamental fish exported from India. It’s also at risk of extinction due to uncontrolled fishing.

To protect the fish from further uncontrolled exploitation, the Indian government has banned the fishing and exportation of the species. It’s now under the National Wildlife Protection Act, which outlaws any capturing except through special permits for research purposes.

Most of the Roseline sharks available today for commercial use are bred in fishery farms. Make sure you get yours from a commercial breeder rather than an illegal exporter.

Species Overview


The Roseline shark is a strikingly beautiful freshwater fish that will add instant charm to your tank. Its look has made it popular among most tank owners. In addition, it displays this beautiful coloration through an active lifestyle, making it a great choice for entertainment.

The species is native to India and is mostly found in fast-flowing river systems and channels. They live in colonies in the mountainous regions of India called the Western Ghats. They stay in four regions: the Chaliyar rivers, Cheenkanni Phuza, the Achankovil, and near Mundakayam town.

The fish prefer the fastest parts of the river with the most oxygen concentration. The place should also have vegetation cover to protect it from predators and direct sunlight.

Roseline Shark Lifespan

Denison barbs can stay up to 5 years in captivity if you provide them with a proper diet and a well-kept environment.

Even though the controlled environment of a tank always works well for the fish’s lifespan, it still wants the best care. Any form of negligence can lead to diseases that shorten their lifespan. While providing the right environment isn’t difficult, you must do some proper homework.

The Appearance of the Roseline Shark

The Roseline Shark is one of the most beautiful fish you can ever have in your aquarium. Its body is covered with multiple colors and intricate details.

It has an elongated, torpedo-shaped body, hence the common nickname, torpedo barb. Its silvery skin with longitudinal black lines also gives it a striking look. Depending on the lighting, a gold or yellow tinge may appear.

The fish has a long lateral line running the length of its body from the snout to the caudal fin. Above the line is a parallel stripe of red. It runs from the top of the snout to the eyes and then disappears at the midsection.

You may also see dark black and yellow stripes on the tailfin and a vibrant red on the dorsal fin.

The fish also tends to change its head appearance as it grows. Upon maturity, it develops a beautiful emerald green on the head.

The male and female Roseline sharks have the same coloration and patterns. You can only spot a difference through the size; the female is mostly larger than the male. The females can also have dull coloration.

The fish is a true work of art that everyone will appreciate. There’s also the rare golden variety that has a higher value. They are created artificially and have red lines minus the black stripes.


Even though the Roseline shark comes in varying sizes, the average size when fully grown is around six inches. Their length provides enough space to showcase their stunning looks, especially when they swim in a group.

Due to its size, you need a spacious tank to keep it comfortable. At the same time, the fish grows steadily and reaches its maximum length within a short time. If you start with a small tank, then prepare to replace it quickly.

Because of their length and torpedo shape, Roseline sharks are excellent swimmers.

How to Take Care of the Roseline Shark

Roseline sharks are easy to take care of. You only need to get the fundamentals right, as they are extremely sensitive to water changes.

Here is the guideline to keep your fish healthy:

Food and Diet

Roseline sharks are natural omnivores that can eat anything you provide. They snack on small invertebrates, insects, and algae in the natural environment.

Providing the fish with a balanced diet helps keep them healthy and supports a vivid coloration. Provide them with standard foods like pellets and flakes as the main diet. You can then add balanced products with carotenoids to help with coloration.

Supplement the dry food with other frozen and live foods. Give them bloodworms, daphnia, brine shrimp, and spirulina.

The Right Tank Size

Getting enough space for the fish is one of the biggest challenges for those who wish to keep it. As an active and energetic species, the fish needs sufficient space to swim and move around. It also grows large when mature and takes up a lot of space. The ideal tank size for the fish is 55 gallons and 4 feet long. However, you will need even more space if you intend to keep a large, multi-species community.

In their natural habitat, the fish move in droves, and even in captivity, they need space to keep moving. It will likely hurt itself in confined spaces as it slams on the aquarium walls and even displays violent behavior. As a rule, any additional Roseline shark in the tank will need around 5 to 6 gallons of space to swim in.

Additionally, install a tight tank cover on your aquarium. The fish tends to jump and can dislodge loosely fitted covers and then jump out.


Roseline Shark does well under normal lighting. However, you can always change the lighting scope to match that of the plants and other additions in the tank.

Recommended Water Parameters

Roseline sharks’ natural habitat is highly oxygenated areas with plenty of vegetation. Replicate this environment in your tank to help the fish reach its full potential. At the same time, the fish can tolerate a range of parameters as long as there are no major fluctuations on a regular basis.

The ideal water parameters are:

  • Water temperature: 60°F to 77°F
  • pH levels: 6.6 to 7.8
  • Water hardness: 5 to 20 dGH

Keep an accurate water test monitor kit to track the water conditions weekly. Test the water frequently when the fish is still new to the aquarium. You can reduce the frequency as the fish gets used to its surroundings.

What do Roseline Sharks Need in Their Tank?

What you include in the tank is as crucial as the water parameters. The fish is an active species that is all about having enough space to swim and explore the open spaces. Without this, the fish can become stressed and lose its color.

Place a layer of sand or fine gravel on the bottom of the tank, then add some pebbles or rocks for a more natural look. Add some plants to give it a feel of vegetation.

The plants in the tank help increase oxygen in the water, increase water quality, shelter the fish, and prevent algae growth.

Due to their active nature, the fish can uproot plants in the tank. Avoid this by embedding the plants tightly in the tank. Some of the plants to include are hornwort, Java fern, pennywort, Anubias, and Bacopa.

The fish also needs some hiding space. Create this by adding rocks, driftwood, and other decorative items. To allow for more swimming space, keep the greenery and decorations to the sides and back of the tank.

Filter System

The Roseline shark needs highly hygienic and oxygenated water, which you can attain by having a working water filtration system. An effective water filter helps you attain a similar rate of flow to that in its natural habitat. Replace 30 to 35% of the water in the tank weekly and vacuum debris regularly to avoid pollution.

Common Potential Diseases

While the fish does not suffer any species-specific conditions, it’s susceptible to diseases that affect freshwater fish. Its natural habitat is clean and hygienic, so failure to keep the environment tidy can lead to some issues.

Some of the common conditions it can suffer from include;

1. Ich

It is the most common disease among Roseline sharks and other freshwater fish. Ich is caused by a parasite and is characterized by white patches on the body. Treat it by administering over-the-counter medication and properly sanitizing the tank.

2. Swim Bladder Disease

This is a condition that impedes the Roseline shark from swimming and buoyancy. Speak to an expert on how best to manage the condition. You can prevent the disease by maintaining proper water conditions and a good diet.

3. Cottonmouth Disease

The condition is characterized by whitish patches around the fin, gills, and head. You can manage it by treating external infections using antibiotics and adding chemicals like copper sulfate to the water.

4. Bacterial and Fungal Infections

The fish is susceptible to fungal and bacterial infections, mostly due to untreated injuries, water quality issues, and exacerbated disease. Provide appropriate medication and sanitize the tank to alleviate the infections. Use erythromycin and other fungal interventions when unsure whether a disease is fungal or bacterial.

Roseline sharks are community fish that interact actively, making them an easy spreader of diseases. Changing the water regularly, removing debris, and having a proper filtration system are all musts to keep your fish safe. Ensure rapid intervention to prevent further spread or fatalities in the case of an infection.

Behavior and Temperament


The Roseline shark is a generally peaceful species that can get along with other peaceful fish. All it requires is enough space to move around. Without enough room, it can start fighting the others and become aggressive.

Always keep them in a group; when kept alone, they will become more aggressive to protect themselves. They get along as a group and tend to spend time together. They make such a lovely sight in the tank with their beautiful coloration.

At the same time, having many of them can lead to them attacking other fish in the community. Always keep an eye on the fish to notice any injuries or changes. Also, the Roseline shark is a fast swimmer that should keep space from slow swimmers as it can lead to accidents and injuries.

Best Tank Mates

Due to its calm temperament, the Roseline shark can get along with other species. However, the ideal tankmate should have similar water parameter requirements and be an active swimmer. They also get along with medium-sized and non-violent fish. Slow fish with delicate fins will struggle against the Roseline shark.

Some of the best options to consider for tankmates include cherry barbs, gouramis, cichlids, tiny stingrays, rainbow fish, and big tetra fish.

Incompatible Species

Even though Roseline sharks never target or bully small fish, putting them together can lead to injuries. It is so fast that it would most likely collide with the smaller ones. The same applies to fish that swim slowly. The slow swimmers will find it hard to keep up with food and other supplies.

The fast movement of the Roseline shark can startle smaller fish like Nanos. They may also eat baby shrimp, such as Dwarf shrimp.

Other fish to avoid include guppies and bettas.

Roseline Shark Breeding

Breeding the Roseline shark is impossible in home aquariums. Instead, they are produced in specialized commercial factories through hormones.

Even though reports have emerged of some keepers breeding them at home, these are yet to be fully verified.

There’s no exact procedure you can use to breed the fish.

Final Thoughts

Nothing makes for a better tank addition than a vividly colored fish that likes to swim. The Roseline shark has the perfect color combination to beautify your tank. They tend to work in groups that intensify their radiant looks, especially with the perfect lighting setup. The fish is also easy to care for; you only need to ensure a clean environment and a proper diet.

Whatever you do, ensure the Roseline shark you add to your tank is from a legal, commercial supplier. This way, you can help protect the ones from the natural habitats that are now endangered.