Data sheet river eel
Latin name:
Anguilla anguilla
Trade name:
River eel, European eel
order name:
Eels (Anguilliformes)
Family:
Anguillidae
Genus:
anguilla
Origin:
Europe, North Africa, Asia Minor
Size (in cm:
Males up to 50, females up to 100
pond size
Content in litres:
from 1000 per eel
water values
Temperature:
4 to 20°C
behavior/stocking
Area:
lower area
Lining:
carnivores, live food (worms, small crabs, insect larvae, spawn, small fish)
Behave:
Loner, predatory fish
Number:
single fish
Life expectancy:
up to 80 years
socialization:
only with big fish
Difficulty level:
Advanced David Perez, Anguilla anguilla 01 by-dpc, CC BY 3.0
General introduction
River eels inhabit open waters, coasts, estuaries, inland rivers and lakes. Unfortunately, the population has declined sharply since the 1970s, so that the species is now known as threatened with extinction applies.
The main reason for the decline is the strong overfishing. Glass eels (juvenile form) are caught in large quantities off the coast of Europe and are mainly sold to Asia. There they are considered a delicacy. Some ends up in European aquaculture and is fattened.
Keeping one or more eels in the garden pond is possible, although not easy. Above all, the animal is prevented from completing its natural life cycle. It cannot migrate to the waters of its birth to mate.
He is spared this exhausting process. That is why river eels live a maximum of 20 to 30 years in the wild. In the pond or basin they can get much older, up to 80 years is possible.
Look
The animals have one typical serpentine body with a round cross section. On the back caudal, dorsal and anal fins form one continuous fin hem. pelvic fins missing, the pectoral fins sit just behind the head.
Its scales are small, oval, and arranged in a tessellated pattern. You are covered by one thick layer of mucus. The Maul is superiorcovered with brush teeth.
The animals are dark gray to black or dark green on the back. The color of the belly reveals the age. In young animals it is yellow, in older animals it is white. Hence the names Yellow eel for young eels and Silver eel for white-bellied animals.
According to the shape of the head, two variants are distinguished, the pointed head and the broadhead. The fish with a small, pointed mouth eat insects and other small animals. Broadheads feed on other fish.
Behave
During the day the fish stay on the bottom between plants or stones. At dusk they become active and go hunting.
As skilled hunters, they track their prey to the surface of the water. Their excellent sense of smell helps them when hunting.
Eels are remarkable animals. They can meander long distances over land and thus get from one body of water to the next. During this time they close their small gill openings. They are able to absorb atmospheric oxygen through their skin. The fish spend the winter buried in the mud.
The animals are catadromous migratory fish. They live in fresh water. They migrate from the lakes and streams to the big rivers and up to the sea to spawn. Your journey begins in October/November. They prefer to be out and about at night and in bad weather.
Once in the salt water, they head towards the Sargasso Sea. It has been proven that Orientate eels to the earth’s magnetic field. Your journey takes about 1.5 years. During this time they do not eat any food, they live on their fat stores.
Once in the Sargasso Sea, they spawn and then die of exhaustion.
The eel larvae (willow leaf larvae) need 3 years for the return trip to the European coasts. Here the larvae develop into glass eels. Glass eels are 7 cm long. They grow into yellow eels and migrate inland into the rivers, streams and lakes.
When the time comes for them to mate, they become silver eels. When they begin to migrate, their back becomes silver-grey and their belly silvery (silver eel). They stop eating and their digestive system regresses. The genitals develop and take their place. The cycle closes when the fish have spawned. An eel only spawns once in its life.
Pond
The animals like it when that water not too warm becomes. It should never exceed 22 °C. It is favorable if a light current reigns and the pond semi-shady lies. Moving water does not heat up to the extent that standing water does.
The floor should be one 15 to 20 cm thick layer of sand, gravel and mulm cover. Some larger stones, plants or caves offer hideouts for the robber. The pond must not freeze to the ground in winter. At least he should 120 to 130 cm deep be. A ice preventer provides enough oxygen.
If the eel does not like the conditions in the pond, it escapes. Then he tries to reach another body of water over land.
gender differences
The males are significantly smaller than the females.
breed
Females become sexually mature at 12 to 15 years, males at 6 to 9 years. It is not possible to breed the migratory fish in the pond.
socialization
The predatory fish should only with big fish to be socialized.