The black ruby barb (''Pethia nigrofasciata'', formerly ''Puntius nigrofasciatus'') or purplehead barb is a

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

cyprinid Cyprinidae is a Family (biology), family of freshwater fish commonly called the carp or minnow family, including the carps, the true minnows, and their relatives the barb (fish), barbs and barbel (fish), barbels, among others. Cyprinidae is the ...

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

Sri Lanka Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka, also known historically as Ceylon, is an island country in South Asia. It lies in the Indian Ocean, southwest of the Bay of Bengal, separated from the Indian subcontinent, ...

, where it occurs in forested streams from the Kelani basin to the Nilwala basin. They are found in streams on hills around in elevation. The brightly colored population introduced to Mahaweli at Ginigathena, Sri Lanka, is said to have diminished in number due to the aquarium export trade.

Description

The young fish has a yellowish-gray body with black vertical stripes. The silver body turns into a dark ruby-red color in mature, breeding males. In the female, the basal part of all the vertical fins is black. In the male, the whole dorsal fin is a deep black, the anal fin blackish red, and the pelvic fins are purple. The fish will grow to a maximum length of with the female being slightly longer than the male.

Water conditions

Black ruby barbs natively live in a

climate Climate is the long-term weather pattern in a region, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteoro ...

among cool, shady, quietly flowing forested streams with either gravel or sand

substrate Substrate may refer to: Physical layers *Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached ** Substrate (aquatic environment), the earthy material that exi ...

s. Their diet mainly consists of filamentous

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

and

detritus In biology, detritus ( or ) is organic matter made up of the decomposition, decomposing remains of organisms and plants, and also of feces. Detritus usually hosts communities of microorganisms that colonize and decomposition, decompose (Reminera ...

. They prefer water with a 6.0–6.5 pH, a water hardness of 5–12 dGH, and a temperature range of .

Commercial importance

The fish has commercial importance in the aquarium hobby, and is successfully bred in captivity. They are also used to create

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two diff ...

forms of " odessa barbs" for the aquarium trade.

Breeding

An egg-scatterer, the fish

spawn Spawn or spawning may refer to: * Spawning, the eggs and sperm of aquatic animals Arts, entertainment and media * Spawn (character), a fictional character in the comic series of the same name and in the associated franchise ** ''Spawn: Armageddon' ...

more than 100 eggs in shallow water among the plants. The eggs hatch in one to two days and then will be free-swimming after 24 hours.

In the aquarium

Plenty of room should be provided for this fish, with plenty of light and a shallow covering of floating plants and ample vegetation (half to two-thirds of the tank area). A layer of

humus In classical soil science, humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a kind of soil organic matter. It is rich in nutrients and retains moisture in the soil. Humus is the Lati ...

should be left on the bottom. This species is good for keeping with other barbs and similar fish. In captivity, the fish are omnivorous, with a healthy appetite. The black ruby barb is an active swimmer that is best kept in schools of at least six.

References

External links

Black Ruby Barb Fact Sheet
{{Taxonbar, from=Q854661 Pethia Barbs (fish) Fish described in 1868 Taxa named by Albert Günther Freshwater fish of Sri Lanka