ROSELINE SHARK (Denison Barb) - Aquarium Care

ROSELINE SHARK (Denison Barb) – Aquarium Care

One freshwater shark endowed with color to beautify your home aquarium is the Roseline shark.

The Roseline sharks are beautiful shark species from the cyprinid family. This fish’s popularity rate in the aquarium trade is on the high side. In other words, aquarists are now recently focusing much on this species.

Western society recognizes this fish. However, they are indigenous to the fast-flowing rivers and hill streams of the Western Ghats in India.

A popular common name of the Roseline shark is ” Denison Barb”.

Keeping a school of this fish species will make you a happy aquarium owner. But, you need to know certain things about this shark to avoid uncertainties.

Hence, this page has got you covered on everything you need to know about the Denison Barb.

Thus, we will take a look at:

  • General Description of the Roseline Shark
  • Where to Find the Roseline Sharks in Nature
  • Threats and Conservation
  • Keeping the Roseline Shark in an Aquarium
  • Breeding and Reproduction

General Description of the Roseline Shark

Roseline Shark Taxonomy

Kingdom: Animalia

Phylum: Chordata

Class: Actinopterygii

Order: Cypriniformes

Family: Cyprinidae

Genus: Sahyadria

Species: S. denisonii

Binomial Nomenclature: Sahyadria denisonii

There other common names of the Roseline shark apart from Denison Barb. These include Red-line torpedo barb and Miss Kerala.

This fish species was named after Sir William Denison (a one time Madras city governor in India 1861 – 1866). And, Francis Day described this species.

Physical Characteristics

The Denison barb has a body shaped like a torpedo. And, the majority of the body covered with silver scales.

There is a black line running the length of this fish to the beginning of the tail. Just above this blackline is a red line that runs from the snout, through the eye and terminating toward the middle of the shark’s body.

A matured Denison barb will develop a distinct green/blue mark right on top of their head.

The claw-ended tail fin of this fish has an alternating yellow and black stripes. On the other hand, the dorsal fin is bright red in color. But, the other fins are somewhat transparent.

This shark species may grow up to 5.9 inches (15 cm) in length. However, that will be on rare occasions. Thus, most of them will just grow between 3.5 to 4.3 inches (9 to 11 cm) in length.

The Roseline sharks are ornamental fish. As such, its popularity comes from the role it plays in the aquarium trade.

Where to Find the Roseline Sharks in Nature

Roseline shark is native to the Pamba, Achenkovil, and Chaliyar rivers in Sothern India. These rivers have high oxygen and known for their fast-flowing water.

The common name “Miss Kerala” is popular in the Indian home market. Also, they refer to this fish as “Chorai Kanni”, literally this translates to “bleeding eyes”.

Though this freshwater fish species was described quite a long time ago (1865), its popularity is recent. In 1996, there was a major collection and export of this fish species out of India. As such, the Roseline shark won the 3rd prize at “Aquarama 1997” (World Ornamental fish exhibition).

This led to the increased popularity of the fish species. Progressively, by 2007 – 2008 Roseline sharks made up 60 to 65% of all the live ornamental fish exported from India.

As a result of uncontrolled fishing and exporting of this fish species, it is now in danger of extinction. In response, the Indian government placed a ban on the fishing and exportation of the Roseline shark.

More so, it is now under the protection of the National Wildlife Protection Act.

Therefore, most Roseline sharks obtained from the aquarium trade are commercially bred in fish farms. Or, at most the ones that few groups of poachers caught in the wild.

Threats and Conservation

The major threat to the natural existence of Roseline sharks is the over-exploitation of this species for aquarium trades.

Other factors that cause the rapid decrease in the natural population of this shark species include habitat contamination.

Therefore, according to IUCN Red List of endangered species, Columbian shark catfish are among the “Endangered” species.

Keeping the Roseline Shark in an Aquarium

When going to purchase a Roseline Shark (Sahyadria denisonii), be sure to keep an eye out for a look-alike of this fish species, the Sahyadria chalakkudiensis.

The latter species is similar to the former. However, it is larger in size, less colorful, and more aggressive when compared to the known Roseline shark.

Hence, avoid making a mistake.

Challenges of Keeping the Roseline Shark in a Home Aquarium

The most complicated part of keeping Roseline sharks is trying to breed them. Sadly, this process has not been studied enough yet to be done in a home aquarium.

Another quite challenging process is replicating the natural water conditions for your sharks in a fish tank. Of certain, we know the natural habitat consists of fast-flowing and clean freshwater.

As such, there is a need to introduce a fast flow of water. Also, ensure a high oxygen level and very low ammonia and nitrate level.

On the other hand, there is the challenge of keeping a school of at least 6 members of this fish species. Of course, this will require a large tank set up.

keeping only one at a time is not advisable as it will become very timid. And, oftentimes die before the expected life span.

However, do not worry as this fish species is peaceful and would not cause much trouble. Especially, when they are in school.

Tank Requirements

In a Glance

  • Max. Size: 5 to 6 inches.
  • Size of Tank Required: 75 gallons and above.
  • Suitable Tankmates: Tiger Barbs, Zebra danios, Siamese algae eaters, Black skirt tetras, Fast-swimming cichlids (e.g. Bolivian ram).
  • Optimal Tank Temperature : 72 to 77 F.
  • Water PH: 6.6 to 7.6
  • Tank Temperament: Peaceful
  • Feeding: Omnivorous
  • Expected Lifespan: 8 years
  • Minimum Aquarist Experience Level: Beginner (With theoretical care knowledge)

Acclimating the Roseline Shark to a Home Aquarium

Taking your pet shark home from the store, do not immediately introduce them into the tank. Of certain, a sudden change in habitat is harmful to your fish.

What you need to do is take out about 20 minutes of your time to acclimate them to the Tank water conditions. Hence follow this process to achieve it:

First, take out the bag containing the fish and empty the fish into a sizeable bucket. Afterward, use a cup to take water from your tank and slowly pour it into the bucket.

Repeat this process until the bucket is half-filled with water. Then, empty the bucket by half in a sink. Repeat the whole process.

By so doing, you will likely not lose any of your pet fish. And, once your fish adapt to the water, empty the bucket using a fishnet over another bucket of about 5 gallons.

Then, gradually place the fish in the net into your already prepared tank. You are now good to go with your shark keeping.

Recommended Tank Size

To comfortably keep your Roseline sharks from juvenile to adult stage peacefully, you need a tank as large as 75 gallons. But remember the bigger the better.

Note that your pet shark will grow up to 6 inches in length. And, you will need to keep them in a group of 6 members or more.

Certainly, they are active shoaling fish species. Thus, to make your shoal of Roseline shark (Denison Barb) happy provide them with a tank up to 125 gallons large.

Any smaller tank size than the recommended might be okay while they are still juvenile. However, might cause discomfort as they grow.

Some Aquarists might record success with smaller tanks. Well, the Roseline shark grows quite slowly. As such, they take a couple of months to gain about 1.5 inches. And, are among the smallest aquarium freshwater fish species.

But then, do not gamble with your pet fish that must have cost you quite a fortune.

Keeping a Shoal of Roseline Sharks

When you keep the adequate number of members (up to 6 sharks or more) in your school of Roseline sharks, they will become less timid. As such, they come out fully active, swimming together around in their tank.

More so, their colors will become brighter as they gain their natural coloring. This is so as they are happier when together.

On close observation, you might notice some demonstration of aggression among the school members. Do not worry, they will try to build hierarchy within the group.

Once the leader emerges, they will become more peaceful and friendly toward each other. Thus, they will swim together more often.

Managing the Tank Water Condition

In their natural habitat, the Denison barb lives in fast-flowing waters with a high oxygen level. To recreate this in your home aquarium you will need a constant flow of water.

Using an external filter will provide the required high oxygen level and a good flow of water.

The neatness of your tank matters a lot while keeping the Denison barb. This is because, in the shark’s natural habitat, there is usually a very low level of organic contamination.

Of course, these rivers have fast-flowing waters. Therefore, you must keep a strict watch and pay extra attention to the tank water quality. And, make sure to always maintain a clean tank status.

Tank Décor to Add

The tank you keep your pet Roseline shark in will stand out if you can make use of additional decorations. Thus, you can use snags (tree branches suitable for aquariums) and strongly rooted water plants.

The plants you may use include Java moss, fern, Anubias, and plants of Bolbitis.

A tank without enough décor can make your brightly colored pet shark look a bit pale. Just as it happens when they are stressed. Or, there is a change in the composition of the tank water. Also, change of environment and new tank mates can make them lose a bit of their bright coloration.

Also, a tightly fitting tank lid is advisable. Of course, your pet fish is very active and fast. As such, it can jump out of the tank quite easily. Hence, the need for the lid.

Compatible Tank Mates for the Sahyadria denisonii

In captivity, the Roseline shark has a reputation for being peaceful. As such it gets along well with so many other fish as tank mates. This especially includes other peaceful species.

They will go with most African Cichlids. And, because they are not aggressive, they will not pick on other fish species. More so, if you introduce South American Cichlids or other know aggressive fish, your Roseline sharks are fast swimmers and will stay away from them.

Some compatible fish species include:

Species to avoid as tank mates include:

  • Oscar
  • Discus fish
  • Angelfish

Remember that the Roseline shark is an active shoaling fish. Therefore, it will do very great with its species.

Choosing nice tank mates will make your tank end up astounding. Exactly what every tank owner wants.

Feeding the Denison Barb

Your pet shark is an omnivore. Therefore, as they feed on insects and other invertebrates in the wild, they also feed on plant materials. An example is algae.

This characteristic in captivity means that your pet shark will ingest almost anything you have to offer. That is both natural and artificial food materials.

Because the health of your pet shark cannot be overemphasized, feed it dry food such as flakes and pellets. And, mix it up with live and frozen food which includes bloodworm, brine shrimp, and daphnia.

Proper feeding practice will ensure a brighter coloring for your shark.

From the first introduction of the Roseline shark in your aquarium, ensure to feed it with flakes rich in carotenoids and astaxanthin. This will your shark to recover its coloration. Of course, stress from transportation and environment change can make them get paler.

This fish species is peaceful in general evaluation. However, some have shown slight aggression around food. This is mostly visible in tanks with confined spaces.

Breeding and Reproduction

Taking Note of Sexes

It is important to know the sex differences among your Roseline sharks. Especially if you are considering breeding them.

On that note, you must know that there is no special difference between the male and female of this species. In other words, it can be quite difficult to tell them apart.

However, when these fish attain sexual maturity, there is a thumb rule to tell the female from the male. Thus, the female will develop a more rounded body and look larger. While the male maintains a slim and well-shaped body structure.

Breeding Recommendations

Most of the recorded successful breeding of the Roseline sharks took place in commercial fish farms. As a result, most of this fish species on sale came from a fish farm and bred through hormonal injections.

Although, there have been reports of isolated incidents of successful breeding of the Denison barb. But then, there is still no precise recommendations on breeding this shark species in a home aquarium.

However, there are theories from these reports. Thus, the report from Chester Zoo Tank in England suggested that this fish species will require a larger group for spawning to take place. Hence, there would be massive spawning.

This group reportedly achieved a successful spawning process within a more controlled condition. Though, this was after the first accidental successful spawning of the Roseline shark.

Another report came from Germany of several successful breeding attempts. In this case, the process was with 15 sexually matured Denison barb. These fish spawned successfully in a soft (2 – 3 dGH) and acidic (6.0 pH) water. Thus, the sharks sprayed their eggs on a bunch of java moss.

Their theory states that the spawning came about through the gradual decrease of the tank water pH level. This they achieved by adding pieces of peat into the tank.

Other important reports are from India. From Chennai, two amateur fish-lovers, Venkatesh and Murali put a successful effort in trying to breed this fish species.

Another from the Fisheries College in Kerala, Dr. T. V Anna Mercy in 2009 recorded success in breeding Denison barbs.


All these efforts helped to standardize the breeding process of the Roseline sharks in commercial facilities. As a result, Commercial fish farms breed large numbers of this fish species now.

In all, the whole process serves as a major boost to fish conservation and aquarium trade in India.

Concluding Thought

This page holds a detailed description and care process for a Roseline shark (Denison barb). And, with this information at hand, anyone can easily keep this fish species Sahyadria denisonii as an aquarium pet.

Of certain, this freshwater fish is very peaceful in captivity. Just keep to this guide and make your shark happy, you will surely enjoy your shark keeping hobby.

More so, keeping this fish does not require you being an expert. Instead, reading a guide as detailed as this can keep you on track. And, you will do great!

While choosing a Roseline shark, check out other Freshwater Sharks that will make your tank stand out.