About the Denisons Barb
Species Type: Freshwater Fish
Care Level: Moderate. May tolerate only a narrow range of water parameters, have specific dietary requirements including frozen or even live foods, may have behaviors that severely limit potential tankmates or may require a specialized aquarium setup.
Origin: Endemic to southwestern India. Inhabits fast-flowing hill streams and rivers, occurring in shoals in rocky pools with thick marginal vegetation. Water temperature averages 15-25C/59-77F.
Compatibility/Temperament: Generally peaceful, but should not be kept with smaller fish that will likely be seen as food. It's water flow and cooler temperatures limit suitable tankmates to medium-sized barbs and danios, loaches, Garra and Devario species. Must be kept in a group, minimum 8; reports of aggressive behaviour may be due to the fish not being maintained in a sizable group.
Although described back in 1865, this fish only came into the hobby in 1996, and it was an immediate "hit." Most of the hobby fish come from the province of Kerala (India), and reports a couple of years ago indicated the species may be near to extinction as a result of un-regulated fishing. The Kerala government has introduced several conservation measures to protect the species, including a prohibition on collection during the breeding season [Practical Fishkeeping, January 2009]. In 2010 the species finally appeared on the IUCN red list with the status Vulnerable.
This fish is benthopelagic, meaning it swims very close to the substrate where it feeds on benthos (organisms living in, on or close to the substrate) and zooplankton. It requires a good water flow, so the aquarium should be long (5-6 feet but no less than 4 feet) with the filter arranged to create a good current from end to end, replicating a flowing stream. A substrate of gravel and small rocks with thick plants around the perimeter would simulate this fish's habitat. Hiding spots formed of wood or rock are beneficial; aquarists have observed this species playing "hide and seek." The aquarium must be kept cooler rather than warmer, with a temperature not exceeding 25C/77F. Warmer temperatures will make it less easy for this fish to assimilate oxygen.
Females are rounder than males, but otherwise there are no known external gender differences. It has not been easy to spawn, and there are very few reports of breeding in aquaria. Commercial breeding is occurring, presumably with hormone injections. Available fish are most likely to be wild-caught. It can live for more than 8 years.
This species may also be encountered under a number of common names such as Miss Kerala Barb, Roseline Shark, Red-line Torpedo Barb, Red Line Barb and Red Comet Barb, or any combination. It closely resembles Puntius chalakudiensis but that species is larger, less colourful and more aggressive.
Originally described as Labeo denisonii by F. Day in 1865, it was subsequently in the genera Barbus and Crossocheilus before Puntius. Some ichthyologists believe it should be in Crossocheilus.
The genus Puntius was erected in 1822 by F. Hamilton for the spotted barbs, and currently contains some 139 species; the name Puntius comes from the Bangla term pungti (small cyprinids). Some ichthyologists do not recognize all member species as such and believe that a full revision is needed. Rainboth (1996) suggests that the old demised genus Systomus should be reinstated as valid because Puntius currently appears to be a polyphyletic grouping of species. [Polyphyletic means the taxon is composed of unrelated organisms (here, fish species) descended from more than one ancestor, i.e., not from a common ancestor.] Rainboth described physiological differences between certain species in Puntius to support his proposal. At the time of this writing, Puntius is the recognized genus for this species.
Rainboth, Walter (1996), "The taxonomy, systematics, and zoogeography of Hypsibarbus, a new genus of large barbs (Pisces, Cyprinidae) from the rivers of southeastern Asia," Volume 129 of the University of California publications in Zoology.
Denisons Barb Diet
In its habitat it feeds on insect larvae and small crustaceans living on or near the substrate along with some algae. In the aquarium feed live and/or frozen worms, daphnia and artemia (brine shrimp) along with prepared dried foods such as flake and pellet. Vegetable matter such as blanched spinach, zucchini and cucumber may inhibit any tendency to nibble soft-leaf plants.
Attains 6 inches.
Minimum Tank Suggestion
4 feet (90 gallon) but preferably a 5-6 foot tank.
Ideal water parameters for Denisons Barb
Soft to medium hard (5-25 dGH), slightly acidic to basic (pH 6.8 to 7.8) water, temperature 15-25C/59-77F. The species has a high oxygen requirement derived from fast-flowing water.