African lungfish

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African lungfish
African lungfish

African lungfish

Systematics
Superclass : Jaw mouths (Gnathostomata)
Class : Meat finisher (Sarcopterygii)
Subclass : Lungfish (Dipnoi)
Order : Lepidosireniformes
Family : Protopteridae
Genre : African lungfish
Scientific name of the  family
Protopteridae
Peters , 1855
Scientific name of the  genus
Protopterus
Owen , 1839

The African lungfish ( Protopterus ) are a genus in the subclass of the lungfish (Dipnoi). This genus currently (as of 2011) includes four species and seven subspecies. Protopterus is the only genus in the Protopteridae family .

distribution

African lungfish prefer to inhabit the peripheral areas in deep waters in rivers and lakes or live in ponds with low oxygen levels. Other habitats are small streams and swamps. The distribution area of ​​the Ethiopian lungfish ( Protopterus aethiopicus ) is in Central Africa and East Africa . The East African lungfish ( Protopterus amphibius ) lives in the coastal regions of East Africa . The Congo lungfish ( Protopterus dolloi ) inhabits waters in the Congo Basin and the West African lungfish ( Protopterus annectens ) lives in West Africa and Central Africa, with the distribution area extending south to the Zambezi and Limpopo currents .

features

The elongated body shapes are offset with soft, partly sunken scales. The animals have a continuous dorsal fin, caudal fin and anal fin. In contrast to the Australian lungfish , which only has one lung, they have two lungs that are located ventrally on the foregut. They have internal gills, which are, however, severely regressed and are therefore not available for gas exchange. They mainly breathe through the skin, drawing oxygen from the water. The lungs are only used during fast hunting, when they are startled and during the dry season (summer sleep).

Locomotion

African lungfish move in shallow water or when foraging on the bottom of the water with the help of their paired fins. The paired fins take turns. In middle layers of water or when taking a breath, they meander forward , like an eel .

Food and hunting

African lungfish are carnivores. The diet consists of crustaceans , molluscs and insect larvae. Larger species also feed on fish and other species. They sneak up on their prey at a slow pace or they lurk in ambushes . When the prey is close enough, it is sucked into the mouth with a powerful jerk. Then they chew the food through, spit it out and suck it back into the mouth so that the food is well chopped up before it is swallowed.

dry season

Before the dry season begins, the African lungfish burrows. By pressing his body against the wall, he digs a vertical (vertical) passage into the deeper layers of mud, mainly in swamps . The sludge is taken up through the mouth and excreted through the gill openings. If the passage is big enough for the African lungfish, the fish turns its front body 180 degrees and lies with its mouth pear-shaped upwards. At regular intervals the fish emerges from the cave to gasp for air and then crawls back into the cave. This process is continued until the water level has dropped to a level below the mouth. Then the fish remains in the cave and excretes large amounts of mucus. When the water dries up, the mucus around the fish dries into a thin cocoon that keeps the fish from drying out. At the top of the cocoon there is a small opening that the fish keeps free with its tail. This opening opens into the fish's mouth via a funnel and enables it to absorb oxygen. Depending on the length of the dry season, it spends several months in this state. This survival strategy of forming mucus for a protective cocoon is less common in the Ethiopian lungfish, as it is not so often affected by dry seasons. Its caves are mostly covered with water.

During the trance-like summer sleep, the fish feed on the muscle parts of the tail, in which a lot of protein is stored. This diet can reduce the weight of the fish by half.

Reproduction

The spawning season is in certain times of the year and takes place when there is large amounts of rainfall. The nests are created in 40 centimeters deep, vertical or diagonal corridors. The nest of the African lungfish is U-shaped and consists of two vertical tunnels. Between the corridors there is a chamber in which the female lays the eggs. The openings of the corridors can be under water or over water.

species

literature

Web links

Commons : Protopterus  - collection of images, videos and audio files

Individual evidence

  1. ↑ Protopterus on Fishbase.org (English)