Roseline Shark (Sahyadria denisonii): Ultimate Care Guide


The Roseline Shark (Sahyadria denisonii) is an active freshwater fish that inhabits rivers of the Western Ghats in India. In the aquarium hobby, Roseline Sharks are also known as Denison Barb, Miss Kerala, and Red Line Torpedo Barb.

In their native habitat in the Western Ghats, winds from the Arabian Sea accumulate and create immense rain throughout the region. As a result, this region contains marshes and tropical forests teeming with biodiversity. The Roseline Shark is endemic to this fertile region of India and lives among approximately 320 other species of freshwater fish. Currently, Roseline Sharks are considered an endangered species by the International Union for Conservation of Nature (IUCN). Unfortunately, wild Roseline Shark populations have been jeopardized by pollution and exploitive export practices. From 2007- 2009, India’s live ornamental fish exports equated to 1.54 million dollars and denisonii species accounted for approximately 60-65% of such exports. Roseline Sharks are now bred in captivity to circumvent destruction of wild denisonii populations. Aquarists should ensure they obtain Roseline Sharks through reputable commercial breeders and not through illegal export practices.

Roseline Sharks are characterized by a torpedo shape, silver coloring, and a black lateral marking highlighted by a hint of red that is also present on the dorsal fin. Mature Roseline Sharks may also display an emerald green hue at the top of their head. The popularity of the Roseline shark can be attributed to its beautiful appearance and energetic nature.

Roseline Shark
Roseline Shark (Sahyadria denisonii)

Roseline Shark Care

Roseline Shark are relatively easy to keep, but they do have certain care requirements.

Here are specifics on how to properly take care of Roseline Sharks:

Temperature for Roseline Shark

The Roseline Shark is accustomed to a tropical climate but can tolerate a wide temperature range. Ideally, the Roseline Shark should be kept in an aquarium between 72°F to 82°F. Aim to keep tank temperature somewhere in the middle of these parameters to ensure optimal comfort.

Water pH for Roseline Shark

The Roseline Shark requires a water PH between 6.8-7.8. Tank water should be tested regularly to ensure it remains within PH parameters.

Roseline Shark Size

Roseline Sharks will grow to be approximately 6 inches. Female Roseline sharks will grow to be slightly larger and wider than males. The Roseline Shark’s size and concurrent torpedo shape make them powerful swimmers.

Roseline Shark Tank Size

Roseline Sharks are active and social fish that require a tank size that accommodates other companions and plenty of space to swim freely. A 55-gallon, 4 ft length tank is the minimum requirement to accommodate six Roseline Sharks. As Roseline sharks mature, they will come to require more space. In the wild, Roseline Sharks are migratory fish that swim in groups comprised of what can be hundreds of other fish. As a result, captive Roseline Sharks thrive in large groups with plenty of space to accommodate their activity. Generally, the larger the tank, the happier and healthier a group of Roseline Sharks will be. As a rule, each additional Roseline Shark added to a tank will require 6-10 gallons of extra swimming space. Under cramped conditions, Roseline Sharks can injure themselves by running into tank glass or become uncharacteristically aggressive. It’s also important to note that Roseline Sharks will require a secured lid as they are prone to jumping and can easily dislodge an unsecured tank lid and fall out of the water.

Roseline Shark Food & Diet

In the wild, Roseline Sharks are omnivorous fish that consume invertebrates, algae, and insect larvae.  In captivity, Rosaline Sharks can accept a commercially prepared diet comprised of flakes and pellets. However, fresh or frozen foods containing carotenoids or fat-soluble pigments can help the Roseline Shark maintain its vibrant, colorful markings. Fresh or frozen foods may include brine shrimp, bloodworms, daphnia, or small pieces of green vegetables like spinach or broccoli. A varied diet helps ensure Roseline Sharks maintain optimal health. Feedings should be administered several times a day and contain what a group of Roseline Sharks can finish within two minutes. Roseline Sharks are more likely to consume food distributed at midlevel inside an aquarium.

Roseline Shark Lifespan

When adequately cared for, Roseline Sharks can live up to 5 years in captivity.

Roseline Shark Tank Mates

Roseline Sharks are communal fish that should never be kept in isolation. When Roseline Sharks are not socialized their health can deteriorate. As a rule, Roseline Sharks should be kept in a group of at least six other Roseline Sharks. Larger groups of 12 or more Roseline Sharks are preferrable but only if the tank size can accommodate the active swimming space for additional fish. Groups of Roseline Sharks will move in unison throughout the tank, creating a beautiful symphonic display of color. Other compatible tankmates for the Roseline Shark are fish species that require similar tank conditions, are agile swimmers, and do not have delicate trailing fins. Roseline Sharks will do well with medium-sized, nonaggressive species such Angelfish, Cherry Barbs, Odessa Barbs, larger Tetra species, or Rainbowfish. Aggressive or territorial fish such as Red Tail Sharks are incompatible with Roseline Sharks.  Roseline Sharks can injure fish with flowing fins such as Betas or Guppies. Small nervous fish such as Nanos can be agitated by the Roseline Shark’s rampant activity.   The Roseline Shark can consume small variations of shrimp, such as the Dwarf Shrimp. Discus fish can be easily agitated by Rosaline Sharks, who may outcompete Discus fish for food.

Roseline Shark Tank Setup

The Roseline Shark should have an aquarium containing hygienic, highly oxygenated water with a fast flow rate. A capable aquarium filter, such as an external canister filter can help ensure that the conditions are similar to the waters in the Western Ghats. 30-35% of the water should be replaced weekly, and debris should be vacuumed regularly to prevent pollution. Sand or gravel substrate should form the basis of the Roseline Shark’s tank. Roseline Sharks require hiding places made up of smooth stones, driftwood, twisted roots, or caves. That said, aquarium décor should not obstruct or clutter open swimming space. Sharp rocks or pieces of driftwood should be avoided as Roseline Sharks may injure themselves when actively swimming. Hornwort, Pennywort, Java Fern, Vallisneria, and Bacopa can all serve as means of aquatic vegetation and can provide Rosaline Sharks with an additional sense of security. Place greenery firmly at the base of the aquarium as Roseline Sharks can dislodge plants while swimming.  Roseline sharks will do well under most normal lighting conditions. Lighting needs can be adjusted to suit whatever aquatic vegetation is placed in the tank.  Levels of ammonia and nitrites should not exceed 0. As previously stated, the tank lid should be securely fastened at all times.

Roseline Shark Breeding

Roseline Sharks do not typically breed in at-home aquariums. To prevent the destruction of wild Roseline Shark populations, scientists began making strides to breed Roseline Sharks in captivity in the 2000s by injecting fish with Ovaprim hormone. Today India bans the live export of wild Roseline Sharks. Roseline Sharks are usually obtained through commercial breeders who utilize similar hormonal methods and naturalized conditions to induce reproduction. Extremely rare cases of Roseline Sharks breeding in at-home aquariums have been reported with larger groups of fish, but there is little documentation to back up such claims. Attempting to reproduce Roseline Sharks at home is unlikely to be successful and will likely result in unnecessary stress placed upon the fish.

Roseline Shark Diseases

Roseline Sharks are very sensitive to fluctuations in water quality. Their natural habitat in the Western Ghats has made the Roseline Shark accustomed to lush and pristine water conditions. As a result, dirty tank water can make Roseline Sharks fall victim to an array of diseases. While no known species-specific ailments affect Roseline Sharks, they are susceptible to many diseases commonly found in other freshwater fish. Such conditions may include Ich, Swim Bladder Disease, Bloat, Cotton Mouth Disease, and an array of bacterial and fungal infections.

  • Ich is a prevalent condition found among Roseline Sharks. Ich is brought about by a parasite that produces crystal-like white patches along the body. Ich is treated by administering medications such as Ich- X, properly sanitizing tank conditions, and addressing any secondary infections brought about by the open lesions created by parasites.
  • Swim Bladder Disease will produce symptoms that impede swimming mobility and buoyancy. Swim Bladder Disease is treated based on the underlying cause that an aquatic veterinarian must usually identify. Measures to prevent swim bladder disease include an appropriate diet and good water conditions.
  • Bloat presents itself as a distended abdomen. Like Swim Bladder Disease, Bloat is treated based on the underlying cause. Food is usually withheld for a period.
  • Cotton Mouth Disease will manifest as white grayish patches around the head, fin, and gills. Treatment is usually comprised of antibiotics and appropriate additives to tank water.
  • Bacterial infections can manifest internally or externally and are usually evidenced by red streaks, ulcers, growths, popping eyes, or bloating. Addressing a bacterial infection will involve disposing of any spoilt food, cleaning the tank, and administering broad-spectrum antibiotics.
  • Fungal infections manifest themselves through white fuzzy growths on the body and are brought about by water quality issues, untreated injuries, or an exacerbated disease. Medications and a sanitized tank can help alleviate fungal infections. When it is unclear whether a condition is bacterial or fungal erythromycin may be provided in conjunction with antifungal interventions.

Because Roseline Sharks are social fish that thrive in groups, diseases can spread rapidly in Roseline Shark communities. Regular water changes, an adequate filtration system, and debris removal are the best ways to prevent illnesses. When signs of disease are observed, rapid intervention can prevent fatalities or further spread.

Where Can I Find Roseline Shark for Sale?   

Roseline Sharks range in price from approximately $8.99-24.99 USD. Larger, more mature Roseline Sharks are typically more expensive. Those planning to purchase Roseline Sharks should acquire a group of six or more fish and plan for prices to increase proportionately. Ideally, Roseline Sharks should be kept in groups of twelve. This communal fish will deteriorate when isolated. Roseline Sharks should be acquired from reputable fish stores or breeders that do not rely on illegal exports of endangered populations. Healthy Roseline Sharks brim with energy and vitality.  Aquarists dedicated to providing sufficient space and pristine water conditions will enjoy witnessing Roseline Sharks thrive in harmonious groups.

Fish Laboratory

With decades of collective fishkeeping experience, we are happy to share the fish care tips that we've picked up along the way. Our goal at Fish Laboratory is to keep publishing accurate content to help fishkeepers keep their fish and aquarium healthy.

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