Dawkinsia denisonii – Denison Barb
Dawkinsia denisonii was first described in 1865 by Day. The current genus name is Dawkinsia, in honor of Richard Dawkins a famous evolutionary biologist. The species name is a reference to Sir William Denison , he was governor of the province of Madras in India in the 1860s. Their common name is Denison Barb.
Synonyms: Labeo denisonii, Barbus denisonii, Crossocheilus denisonii, Puntius denisonii, Sahyadria denisonii.
Origin
Kerala and Karnataka states in India. At present, they inhabit fragmented parts of some rivers and streams. They can be found there in clear and oxygenated water.
Description
Dawkinsia denisonii can reach a length of about 15 centimeters. Sometimes, this fish is called Red Line Torpedo Barb. Their body is shaped like a torpedo, they have silver scales and a red horizontal line runs from the head through the eye to the middle of their body, below that a black horizontal line runs from the head to the tail. They have the colors yellow and black at the end of their tail.
Denison Barb is an active schooling fish that you can keep with at least 6 pieces in a large aquarium. They are very suitable for a community aquarium. You should take into account the rather busy behavior of this species. They are fast swimmers, and certainly, at warmer temperatures, they can become quite busy. They are fairly new fish in the aquarium hobby. They swim in the upper and middle layers of water.
The differences between males and females can be subtle. Females tend to be larger and more robust in build than males, and they typically have less vibrant coloration. If you observe a group of these animals for some time, you will naturally start to notice distinctions in the adult individuals.
What is the maximum age a Denison barb can reach?
A Denison Barb can live up to five to eight years with proper care and conditions.
The Aquarium
These fish need an aquarium that is at least 1.50 meters long. Decorate the aquarium with dense plants along the edges while ensuring there is ample swimming space. It’s a good idea to use hardy plants since they enjoy nibbling on them. Dawkinsia denisonii prefers moderate water currents and clean water, so regular water changes are recommended.
Water parameters
Temperature: 15-25 degrees Celsius.
PH: 6,5-7,8
GH: 5-25
Diet
They are omnivores and can eat live food, frozen food, greens, and dry food. Ensure they receive a balanced diet to stay healthy.
Breeding Dawkinsia denisonii
Breeding this species is quite challenging and typically occurs only by chance. In commercial settings, Dawkinsia denisonii is often cultivated using hormones. Various attempts have been made to understand the breeding process, leading to several theories. One theory suggests that gradually increasing the temperature over several days can mimic the natural conditions during the species’ breeding season in the wild. Another theory proposes that lowering the pH may stimulate breeding behavior. However, it remains uncertain how to effectively promote breeding. It’s likely that breeding success increases with the use of a large group of these fish.
In the wild, they lay their eggs during the monsoon (rainy season) from November to January. Usually, they lay eggs twice a year. The 300 to 1,000 eggs are placed between stones on the ground. The eggs hatch after about three to four days.
If you are lucky and your Dawkinsia denisonii reproduce, you can feed the fry with infusoria. When they have grown a bit, you can switch to micro-worms.
Particularities
The Denison Barb is classified as endangered by the IUCN. The population of Dawkinsia denisonii has decreased by 50% in recent years, with some key fishing areas experiencing a decline of up to 70%. This decline is primarily due to overfishing for the aquarium trade. Additionally, pollution and habitat loss have also significantly contributed to their decrease.
Video
Authors
Coby
Rickpad
John de Lange
Copyright images
Hristo Hristov
Andy Gordon
Gerry Verrier
References
IUCNRedlist
Molecular phylogeny and divergence of major clades in the Puntius complex (Teleostei: Cypriniformes)
Biotopeaquariumproject.com