Since ancient times, among many peoples, one of the most popular fictional creatures was the unicorn. Although they described it in different ways, they always represented it as a horse with a single horn coming out of its forehead. Perhaps for this reason, some representatives of the animal world with similar outgrowths on their heads, including fish, began to be called unicorns.
The article provides information about the unicorn fish: photo, description, habitat features, etc.
General Description
Today, about 16 species of unicorn fish are known, whose habitat is exclusively tropical waters of the Indian and Pacific Oceans. These are fairly large fish. They reach up to 70 cm in length. They are characterized by a flattened laterally and relatively high body, covered with small and rough to the touch scales. The tail does not have a notch, but it has elongated filiform outer rays. On both sides of the body on the lateral surface of the caudal peduncle there are bony shields that perform a protective function. They are equipped with a pointed spine orkeel.
Adult fish are grayish or olive in color, while juveniles are mostly light gray with almost imperceptible tail spines. Unicorn fish (or rhinos) got their nickname due to the presence of a long horn on the forehead or a pronounced hump in older individuals. It should be noted that in males it is more massive than in females, and young fish have only a small pointed protrusion on their foreheads.
Adults predominantly live in coastal wave areas of the outer slopes of rocky shores and coral reefs. You can meet them in large schools, flocks and one by one.
Locals eat the meat of this fish, despite the fact that it has a bitter taste and even often causes poisoning.
Lifestyle, reproduction
These fish are mostly secretive diurnal lifestyle, feeding quite actively. Their diet includes attached brown algae. Together with them they eat benthic invertebrates of small animals. The diet of some species includes corals, hydroids and even sponges.
Spawning of unicorn fish occurs on full moons in December-July. During the breeding season, they keep in flocks, from which small spawning groups are separated from time to time, sharply rushing up. Females spawn in the surface waters of the ocean. They have a small pelagic, and their development after fertilization in the tropics lasts about a day.
The larvae that emerged from the eggs are alreadyafter 5 days, they begin to actively feed on planktonic organisms. Initially, they do not have any external similarities with their parents, so for a long time they were classified as independent species. After 2–3 months, the larval stage ends, and young fish begin to approach the shores, where they undergo transformation within 5 days. They become like adult fish.
During this period, there is a change in color, and the lengthening of the digestive tract (about 3 times) due to a change in diet (less high-calorie algae). In the coastal part of the ocean, juveniles quickly grow stronger and grow, gradually moving to deeper reef zones. It is characteristic that the fry of unicorn fish have a normal-shaped head. Their typical forehead horn appears only when the head is over 12 cm long.
Unicorn comb fish
Information about unicorns would be incomplete without mentioning a little-studied and rare representative of the ichthyofauna of deep waters. Its English name literally translates as unicorn comb fish. Only 3 varieties of these unique fish live in the tropical zone of the oceans. They are found everywhere at depths of more than 1,000 meters.
These marine animals are characterized by a thin elongated silvery body (150 cm - the size of adults) and the presence of a long red dorsal fin, stretching from the head to the very tip of the tail.
The comb fish got its name for a solid horn-shaped outgrowth located on the head. It is located on the upper jaw and protrudes far forward. Scientists believe that the main attraction of this fish is the ink bag, which allows it, in case of danger, to throw out a cloud of ink from the cesspool and go away under its cover. Although the same scientists believe that a black cloud cannot help escape in such darkness from an attacking predator, which most likely finds its prey by smell or by the vibrations of the water.
Narwhal whale
The unicorn whale fish is included in the Red Book list and is an inhabitant of the Arctic seas. This is the rarest whale in the world, and the most mysterious animal in the ocean.
It has a large horn (or tusk) making it special and unique. The tooth of the male with age turns into a tusk, twisted in a spiral. It is about three meters long and weighs up to 10 kg.
An interesting fact is that the rest of the teeth of these whales do not turn into tusks.
Aquarium life
Because some species of horned fish (unicorns) adapt easily to captive living conditions, they can be found in a number of aquariums and large marine aquariums. They can live in them for years. But their maintenance requires huge volumes of water (for one individual, about 1,500 liters). Moreover, open water spaces should be combined with a large number of stones overgrown with algae, since it is in such conditions that these fish grow to the largest sizes and grow a horn.
