Image – Wikimedia/Astellar87
The Labeo bicolor (Epalzeorhynchos bicolor), also commonly known as the black shark or red-tailed shark , is one of the most peculiar and striking fish in the aquatic world. This fish belongs to the Cyprinidae family and primarily inhabits the rivers of Southeast Asia, particularly Thailand. Unfortunately, the Labeo bicolor has been classified as an endangered species in its natural habitat, although its controlled breeding in captivity is quite common, allowing it to remain popular among aquarists.
Characteristics of the Bicolor Labeo Fish
The black sharkfish is distinguished by its elongated, slightly laterally compressed body, giving it a hydrodynamic appearance ideal for swimming in fast-flowing waters. It has two pairs of barbels in its mouth, which it uses to both detect and search for food on the substrate. Furthermore, a visual characteristic that gives it the name 'shark' is its dorsal fin , very similar to that of marine sharks.
Its coloring is another of its main attractions: its body is completely matte black and its tail is a deep red that stands out in a surprising way. There are other variations of this species, such as an albino variant, in which the body is white instead of black, but it maintains the same vibrant red color in the caudal fin.
Sexual Dimorphism
Sexual dimorphism between males and females is subtle but noticeable to the trained eye. In general, females tend to be more robust and larger than males. Additionally, their coloration is usually paler. Another distinguishing feature is that the dorsal fin of females ends at a right angle, while in males it is more pointed.
Natural Habitat of the Bicolor Labeo
Originally, the black shark fish was widely distributed in the rivers of Thailand, primarily in water systems such as the Chao Phraya and the Mae Klong . They are found in fast-flowing habitats with substrates of sand, stones, and dense aquatic vegetation. Their diet in the wild includes all kinds of small invertebrates, vegetation, and phytoplankton.
Unfortunately, due to overfishing and habitat destruction, the Labeo Bicolor has disappeared from many of the areas it once inhabited, and has therefore been classified as endangered in its natural environment.
Aquarium Care
Image – Wikimedia/Astellar87
Keep in mind that this type of fish needs an aquarium of at least 150 liters due to its size in captivity, which can reach up to 15 cm. The aquarium should recreate its natural habitat as closely as possible, so it's ideal to have plants, driftwood, and rocks that provide hiding places. However, it's also essential to leave enough space for it to swim freely.
To ensure the well-being of your black shark fish, it's recommended to maintain stable water parameters. The optimal temperature for this fish is between 23 and 27 °C, while the water's pH should be between 6.5 and 7.5, and the water hardness should be kept between 9 and 16 dH.
- Temperature: 23°C to 27°C.
- pH: Between 6.5 and 7.5.
- Hardness: 9 – 16 dH.
Behavior and Sociability
The Labeo bicolor is a territorial , solitary, and very active fish. Although it can coexist with other species, it is recommended that it not be kept with others of its own kind, as they tend to be extremely aggressive towards each other. In community aquariums, it can coexist with similarly sized species, such as loaches, barbs , and other cyprinids, provided there is enough space for them to establish their territories.
Its behaviour includes chasing other fish if they invade its territory, but it rarely causes them any harm. It usually stays in the lower and middle levels of the aquarium, searching for food in the substrate and marking out its space.
Food
Omnivorous by nature, the black shark fish accepts a wide variety of foods. Its diet should include dry foods (flakes, granules), live foods (tubifex worms, brine shrimp, mosquito larvae, etc.), and plant supplements such as spinach or algae . Including spirulina in its diet is also recommended to ensure its well-being.
In captivity, it is important to offer a varied diet to prevent this fish from nibbling and damaging the aquarium plants. It is a fish that feeds primarily on the bottom of the aquarium, so you can offer it sinking foods.
Reproduction
Breeding the Labeo bicolor in captivity is extremely difficult and has only been achieved on very rare occasions. To induce reproduction, some researchers have resorted to injecting carp pituitary glands into mature specimens. However, these methods are complicated and not always successful.
During the reproduction process, the female can lay up to 1000 eggs, which must be kept in constant movement to prevent them from sinking and becoming non-viable. The fry are born pale in colour, but as they grow, they acquire the characteristic colouring of the adults, with a black body and red tail.
Common diseases
Despite being a fairly hardy species, the Labeo bicolor can be affected by some common aquarium fish diseases, such as ich ( white spot disease ) and fin rot . Stress from poor aquarium conditions, such as sudden temperature changes or poor water quality, can make the fish more susceptible to these diseases.
It is easy to notice when a Labeo Bicolor is stressed or sick, as its coloration often becomes paler than normal. To avoid these problems, it is crucial to maintain the water quality within the parameters mentioned above, ensuring that the aquarium has good filtration and water circulation.
In the long run, a well-maintained aquarium and a balanced diet will ensure your black shark fish stays healthy and can enjoy a long and active life, with a lifespan that can reach 17 years in captivity if given proper care.