|Genus & Species: Sahyadria Denisonii|
|Common Names: Denison’s Barb, Red-Line Torpedo Barb, Miss Kerala, Roseline Shark, Torpedo Barb|
|Temperature: 65 – 77ºF (18 – 25ºC)|
|pH: 6.5 – 7.8|
|GH: 5.0 – 15 dGH|
|Max Size: 10 – 15 cm (4 – 6 inches) in length|
|Lifespan: 5 – 8 years|
|Depth Preference: Mid dweller|
|Tank Size: 40 gallons|
The denison barb is an excellent choice for the majority of aquarium setups, making it the perfect dither fish for aquariums with aggressive fish or community tanks looking for compatible tank mates that are peaceful.
Origin & Habitat
Denison barbs are a freshwater species of fish endemic to the Western Ghats in India, bordering the States of Kerala and Karnataka. They are found in various fast-flowing rivers and streams such as Achenkovil, Pamba, and Chaliyar rivers.
Their natural habitat consists of shallow rocky pools with moderate to strong currents. With over 600 aquatic plant species within their range, they live in some of the densest populations of aquatic fauna inhabiting India.
Denison Barb Care
Since they are moderately sized fish and active schooling species, a large aquarium should be provided with a filtration unit that is capable of producing adequate water flow similar to their natural habitats.
Since they originate from swiftly moving, clean waters, they cannot tolerate even very low concentrations of ammonia or nitrite, and the buildup of nitrates and other organic waste can have a negative impact on their health.
This species is known to jump out of the water on occasion, so a tight-fitting aquarium lid is recommended.
Denison Barb Diet & Feeding
In the wild, denison barbs prey on small insects, crustaceans, and worms while also feeding on plant material and other organic debris. An omnivorous species of fish, a healthy diet will consist of various foods that contain algae, plant, and protein-based nutrients.
In addition to feeding your denison barbs with a high-quality commercially made flake or pellet food, regularly supplementing them with a couple of other algae-based and protein-based foods will ensure that they receive the proper nutritional requirements. Color-enhancing foods with astaxanthin or taurine are known to increase their pigmentation.
Daphnia, microworms, infusoria, and brine shrimp that have either been procured or cultivated by trusted sources to avoid parasites and diseases are great sources of live foods. In addition, protein-rich dried or frozen foods such as blood worms, insect larvae, insects, tubifex, and brine shrimp are readily accepted.
Blanched vegetables such as zucchini, cucumber, peeled peas, and squash will alleviate bloat and remedy any digestive issues. They will also actively eat any algae that may come across in your aquarium and lightly nibble on some species of fine-leaved plants. Although, do not rely on them to rid your aquarium of algae. Lastly, spirulina is a popular algae-based ingredient that can be easily found in flake or pellet forms at your local pet store.
Tank Mates & Temperament
The Denison Barb is an active species of fish that congregate in schools and should be kept in groups that are larger than 6 – 8 otherwise they tend to become rather timid in smaller numbers. They are rather peaceful and one of few species of barbs that do not nip fins.
It is also best to keep either an even male-female ratio or stock more females than males, an overpopulated male tank will constantly chase and stress out the females.
Denison barbs do not seem to bother most snails and larger species of shrimp, but they will prey on dwarf shrimp and other small invertebrates.
Ideal denison Barb tank mates are angelfish, barbs, corydoras, dwarf cichlids, danios, rasboras, livebearers, loaches, tetras, catfish, and plecos. Virtually any tropical fish that do not eat smaller fish and prefers similar water parameters.
Male & Female Differences
Sexual dimorphism can only be observed in denison barbs once they reach sexual maturity, males will become fully mature at a smaller size than females. On average, males are fully mature once they reach the length of 8.5cm (3.3 inches) and 9.5cm (3.75 inches) for females, plus or minus 1 cm.
In males, the red stripe running across their body is typically brighter red and longer than in females. However, the most common sexual dimorphic character observed in mature specimens is the female’s wider body while males are slender in comparison.
The most effective method would require careful handling of the fish. Gently pinching their abdomen will cause their abdomen to become translucent enough to visibly notice the female’s eggs or a male will produce secretions near their anal fin.
Breeding & Spawning
Denison barbs are an egg-scattering species of fish that exhibit no parental care, the fish fry will freely spawn within 36 – 48 hours post fertilization with an average length of 1.19 mm. Spawning seasons occur during the fall typically starting in October and ending in March.
In aquariums, instances of naturally occurring spawning behavior are extremely rare and usually happen by accident. Chester zoo in the UK has successfully bred denison barbs, their hypothesis was on the basis of large schools.
Denison barbs are predominately bred in captive breeding programs and commercially via artificial fertilization, using ovaprim or ovatide as an inducing agent.
There is very little information on their spawning behavior in the wild, they are known to be very sensitive to changes in solar radiation, precipitation, current, and many other aspects relating to their ecological surroundings. All of these factors and other unknown ecological occurrences are likely to be the cause of natural spawning behavior.
Previously, the genus Puntius was considered to be a polyphyletic universal term that included over 100 different species, but this problem has now mostly been addressed. Older publications that use Sahyadria Denisonii’s former names frequently refer to it as Puntius Denisonii or Labeo Denisonii.
In 2013, the denison barb was moved into a new genus that was named Sahyadria from its first described genus Puntius. Along with Sahyadria Chalakkudiensis which shares a striking resemblance to Sahyadria Denisonii, they are currently the only two barb species described in this genus.
To differentiate between the two, Sahyadria Denisonii has an absence of a black marking on their dorsal fin, and as they mature they will begin to develop a distinctive greenish-blue marking on the top of their head. In contrast, Sahyadria Chalakkudiensis is a larger, less colorful, and more aggressive species.
Denison barbs are currently listed as an endangered species in the wild and have been included in India’s Schedule I of the Wild Life (Protection) Amendment Bill, 2021. The golden form is believed to be extinct from the wild but is still bred in captivity.
The following set of characters is used to identify the genus: a single pair of maxillary barbels, mature size 85 – 190 mm SL; the posterior unbranched ray is weak, segmented apically, and unserrated, and the posterior branched ray can bifurcate at the base to appear as a ninth branched ray on the dorsal fin; five branched and two to three unbranched rays on the anal fin; full lateral line with 26 – 28 pored scales; missing free uroneural; simple, acuminate, and grouped in two rows, each with 12 and 18 rakers; absence of the antrorse predorsal ray and absence of the post-epiphysial fontanelle: 5 supraneurals; infraorbital IO3 slender, not overlapping preoperculum; 5+3+2 pharyngeal teeth; 16 abdominal and 11 caudal vertebrae.
The color pattern consists of an upper scarlet stripe running from the snout to the midbody, a wide blackish lateral stripe running from the snout to the caudal-fin base, a yellow stripe running from the operculum to the hypural region between the black and scarlet stripes, caudal fin lobes with oblique black bands covering the posterior quarter and subterminal oblique yellow bands, and a dorsal fin with or without a black blotch.
Sajan S. Captive Breeding and Developmental Biology of Sahyadria Denisonii (Day 1865). 2015
N. Mahadevi, S. Felix, B. Ahilan, and C. Rajagopalasamy. Evaluation of reproductive performance in indigenous endemic ornamental fish Sahyadria denisonii using hormones under captive environment. 2019
Rajeev Raghavan, Siby Philip, Anvar Ali, and Neelesh Dahanukar. Sahyadria, a new genus of barbs (Teleostei: Cyprinidae) from Western Ghats of India. 2013