Horned teeth are another representative of double-breathing fish. But if African protopters have 2 lungs in their arsenal, then there is only one Australian horned tooth. In this regard, zoologists had to identify them in a separate family - horned or one-lung.
Horned Tooth or Barramunda (Latin Neoceratodus forsteri) (Australian Lungfish)
These are very ancient fish. Their heyday came in the Devonian period of the Paleozoic era (395-345 million years ago). At that time, about 100 species of double-breathing fish were isolated and they were found almost everywhere. By the time of the reign of the dinosaurs - the Cretaceous period of the Mesozoic era (135-65 million years ago) - only 2 representatives remained from bipedal fish, surviving to this day - these are horned teeth and scalets.
The former survived only in a few bodies of water on the Australian mainland. These are the Mary and Burnett River Basins in Queensland in northeast Australia. A little later, they got to part of the reservoirs and lakes of Queensland, where they also took root safely.
They got their name - horned teeth - thanks to the zoologist and naturalist Jean Louis Agassiz (Agassis) (1807-1873), the author of works on fossil fish and echinoderms. In the mouth of these fish on the palate and on the lower jaw are large plates of fused teeth - a kind of grater teeth. Such "jaws" used to come across only in fossilized form. Therefore, the professor called these fish ceratodes or horned teeth.
Something like a blackhead, they are much larger and their entire body is covered with large scales. The size of these fish is impressive: length - up to 175 centimeters, weight - about 10 kilograms. The body is slightly compressed laterally, especially in the tail region. Color can vary from tan to bluish gray. The sides and abdomen are lighter. All 4 fins are directed downward and somewhat resemble legs.
These fish prefer slowly flowing or standing bodies of water with enough aquatic vegetation. It seems that they are specially created for life in stagnant, decaying water. When in a superheated water, almost devoid of oxygen, all living things die and from their decaying corpses the water turns into a terrible fetid slurry, horned teeth are the only ones who can survive in this "hell".
Lack of oxygen in the water is not a big problem for double-breathing fish. Thanks to the lungs, they can provide their body with oxygen. But if the pond dries up completely, then unlike protopters, horned teeth die because they need water for life, and they can’t dig into the ground. In such an abode, they wait for the rainy season.
The horned tooth, unlike the protopter, has only 1 lung, but it is enough. Gills are well developed, so the lung is used only in extreme cases, one of which we have already described above. The fish rises to the surface every 30-40 minutes and takes a long and loud breath, filling the lung with air. Exhalation and inhalation occur through the nostrils, which the fish neatly exposes above the surface of the water. At the same time, her jaw is tightly closed.
Horned teeth are sedentary fish, so they easily fall into aboriginal nets. Most of the time is spent in one place, lying on the belly or resting the body on all 4 fins and a huge tail.
Hungry, the fish goes in search of food. She begins to move slowly along the bottom due to smooth and slow bends of the body or supporting herself on the fins. Only in the event of a sharp fright, the horned tooth can make a maneuver, abruptly jerking off to the side somewhere, but it is not capable of long speed swims, therefore it is quickly exhausted.
They are active both day and night. They feed on various invertebrate animals: small crustaceans, mollusks, worms, insect larvae and other aquatic animals. The hornbeam larvae feed on filamentous algae for the first time. The production is not enough, but is sucked in with the water. Therefore, sometimes, along with animals, vegetation enters the intestines of fish. No harm from this “vegetarian food”.
Horned teeth are bad parents. Their spawning period is long - from April to November, but the peak passes during the rainy season - September-October. The main requirements for the spawning site are dense aquatic vegetation, oxygen saturation and shallow depth - not more than 1 meter.
Many fish gather in one place. The sex ratio is as follows: there are five males per female. And then marital dances begin, which include a number of specific movements. During the dance, the female throws eggs, and the males floating nearby fertilize her.
After spawning, adult individuals swim away, and caviar remains without “parental care”. Large eggs settle among the vegetation, which serves as a shelter for them. They contain a large amount of yolk, which for the first time will become the only food for hatched fry.
Crowned Tooth Caviar
Larvae appear after about 1.5-2 weeks. They do not yet have gills, and unlike protopter larvae, there is no cement gland that secrets a special sticky secret that allows it to attach to a different surface. Therefore, the larvae of the horned tooth are located at the bottom and almost all the time lie motionless until they consume all the yolk reserves. After 2 weeks, they turn into fry and they have pectoral fins.
After 4-5 months, the fry are already becoming like adults. From the same age, they switch from plant food to "animal".
Tasty red horned meat is loved by the locals. But this fish is currently under protection and its capture is strictly prohibited.
The Australian Horned Tooth, or Barramunda (Latin: Neoceratodus forsteri) is the only representative of the Horned Tooth family (Neoceratodontidae) from the order of the Horned Tooth (Ceratodontiformes). This double-breathing fish is called a living fossil. The age of its fossilized remains found in the Australian state of New South Wales is estimated at approximately 380 million years.
Lungfish flourished in the Devonian about 413-365 million years ago. To date, only 6 species have survived, of which 4 live in Africa and one in South America. A horned-tooth swimming bubble has turned into a primitive lung, thanks to this it can breathe atmospheric air and survive drought.
Being in a shallow puddle, the fish are able to not use the gills for several days.
The species was first described in 1870 by the German zoologist Johann Ludwig Krefft and named after the British colonist William Forster, the fourth prime minister of New South Wales (1859-1860).
Barramunda is endemic to Australia and does not occur in vivo outside the continent. The habitat is small and covers the Mary and Burnett river basin in the north-east of the country in Queensland. There he was also settled in artificial ponds and reservoirs, where he successfully took root.
In recent years, work has been carried out on the settlement of the Brisbane, Kumera and Stanley rivers by Australian horned teeth. Fish lodges in stagnant water bodies with mud. In rivers, she selects areas with a slow course and overgrown with abundant aquatic vegetation.
The Australian horned tooth adheres to a sedentary lifestyle. In the afternoon, he usually rests, lying on the bottom. With the arrival of dusk, the predator leaves its shelter and goes in search of food. He produces it in the bottom layers of water.
The basis of his diet is bivalves, snails and worms. He easily breaks their hard shells with his powerful jaws with horn plates. To a lesser extent, the daily menu is complemented by frogs, tadpoles, fish, insects and aquatic plants.
In drought, when oxygen in water becomes low, the barramunda rises to the surface at least once every 30-40 minutes for another portion of fresh air.
When exhaling, a characteristic noise is heard, resembling a deflated balloon. The circulatory system of the catfish, in contrast to other bipedal fish, is more separated from the pulmonary. He has one lung, not two, like everyone else. It has a low oxygen absorption efficiency, therefore, it cannot completely replace the gill for a long period, as, for example, in the brown protopter (Protopterus annectens).
Spawning begins at the end of the dry season from August to December before the rains, when the water temperature warms above 20 ° C. The male digs a nest at the bottom in the form of a small hole located among the algae. After a short courtship, the female lays eggs in it resembling a frog.
Eggs with a diameter of about 7 mm are covered with a sticky gelatinous shell.
Incubation lasts 10-12 days. All this time the male is nearby and guards the masonry. The hatched larvae of the first days almost motionlessly lie at the bottom until the formation of external gills, breathing their skin. Then they become active and move to shallow water, where they first feed on filamentous algae, and after 3-4 months pass to small invertebrate living creatures. The pectoral fins in them form after 2 weeks, and the ventral fins not earlier than 10 weeks.
Under favorable conditions, fry grow to 20-25 cm in six months.
Australian Aquarium Tooth Content
For adult fish, you need a large aquarium with a minimum volume of 2500 liters. The flow of water in it should be minimal. At the bottom lay a layer of silty or sandy substrate, stones and driftwood for shelters.
The aquarium is located away from the windows in a darkened place, the lighting is used as weak as possible. It can contain only one individual.
Representatives of this species are aggressive towards other fish, including their fellow tribesmen.
Water temperature is maintained in the range of 20 ° -26 ° C, acidity in the range of pH 6.5-8.0. The distance from the surface of the water to the lid of the aquarium should be at least 15 cm so that there is enough air for breathing. Adults are fed once a week. They are fed shrimp, shellfish, seaweed and small fish.
The length of the massive elongated body is about 90 cm. Individual specimens grow to 175 cm and weigh up to 43 kg. The upper part is brownish-olive or bluish-gray. The belly is lighter, dirty white or yellowish.
The skin is covered with large scales. Fleshy pectoral and abdominal fins are used as limbs for slow movement along the bottom.
The life span of an Australian horned tooth is 60-90 years.