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. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

cyprinid Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest verte ...

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

endemic Endemism is the state of a species being found 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 found elsew ...

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

, where it occurs in forested streams from the Kelani basin to the Nilwala basin. They are found in streams on hills around 1000 ft (300 m) in elevation. The brightly colored population introduced to

Mahaweli The Mahaweli River ( si, මහවැලි ගඟ, literally "Great Sandy River"; ta, மகாவலி ஆறு 'mahawali gangai'', is a long river, ranking as the longest river in Sri Lanka. It has a drainage basin of , the largest in the ...

Ginigathena Ginigathena is a small town in Sri Lanka located within Central Province, Sri Lanka, Central Province in the Nuwara Eliya District. It is the central point to reach Hatton, Sri Lanka, Hatton and Nawalapitiya. The Beauty of Tea Estates of Nuwara E ...

, 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 2–3 inches (6–8 centimeters) 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 an area, 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 meteorologic ...

among cool, shady, quietly flowing forested streams with either gravel or sand substrates. Their diet mainly consists of filamentous

algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

and

detritus In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts commun ...

. They prefer water with a 6.0–6.5 pH, a water hardness of 5–12 dGH, and a temperature range of 72–79 °F (22–26 °C).

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 dif ...

forms of "

odessa barb The Odessa barb (''Pethia padamya'') is a species of cyprinid fish known from Central Myanmar, where it is known to occur in an artificial pond above the Anisakan Falls and also from the lower Chindwin River. For many years it has been known to t ...

s" for the aquarium trade.

Breeding

An egg-scatterer, the fish

spawn Spawn or spawning may refer to: * Spawn (biology), 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: Ar ...

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