Zebra cancer

from Wikipedia, the free encyclopedia
Zebra cancer
Zebra crab (male)

Zebra crab (male)

Systematics
Order : Decapods (decapoda)
Subordination : Pleocyemata
Partial order : Large crayfish (Astacidea)
Family : Parastacidae
Genre : Cherax
Type : Zebra cancer
Scientific name
Cherax peknyi
Lukhaup & Herbert , 2008

The zebra crab ( Cherax peknyi ), also known as the tiger crab , is a crayfish that lives in rivers and stagnant waters in New Guinea , where it is also considered an edible crab . Due to its striking drawing, which is reminiscent of the camouflage strips of zebras and tigers, this crayfish has become a widespread aquarium animal in Europe, Japan and the USA in recent years. The species was when it was introduced in Germany in 2000 because of their similarity to Cherax papuanus as Cherax cf. papuanus designated and only in 2008 by Christian Lukhaup and Brett Herbert described .

features

The zebra cancer reaches a size of up to 15 cm and lives an average of 3 years. The males usually have larger claws than the females and are a lot stronger or they get bigger. The sex organs are found on the underside of the animals, on which the four pairs of legs are located. The male has a thorn on the fifth pair of legs and the female has an oval opening on the third pair of legs.

The color variant Cherax peknyi "Tiger" has broad, yellow- orange transverse bands on the back armor of the abdominal segments, which alternate with black bands. In the “zebra” shape, these bands are narrower and light yellow to white.

Way of life

Cherax peknyi can be found in flowing, but also in standing water or the oxbow lakes of rivers. Like most other crabs, zebra crabs are nocturnal . As a rule, they are peaceful crabs, provided there is enough food available in the form of plants, zooplankton and dead fish, they do not hunt any aquatic animals such as fish, shrimp or snails themselves. If, however, there are smaller zebra crabs in their territory, it can lead to confrontations in which the limbs of the opponents can be affected, whereby a complete loss of some limbs can also be the result of a confrontation. Legs, antennae and scissors lost in combat are recreated within a few weeks.

At different intervals (depending on the food available), the zebra crabs shed their old shells and a new one occurs. Immediately after moulting , the new shell is still soft and bendable ( butter crab ), but it hardens after a few days. The old shells are usually eaten as a fortification, as they cover the need for chitin and lime, which are essential for the formation of a new shell. This molt allows the crabs to grow. In some cases, the scissors in particular cannot shed the old shell, which can lead to the death of the animal if the crab cannot shed its limbs on its own.

Aquarium keeping

Zebra crabs need plenty of hiding places and a rich supply of plants. If the aquarium lighting is too bright, the animals become shy and you can no longer see them. They primarily look for food at night and, in addition to live food, also like to eat food tablets, carrots and other vegetables and leaves. Food tablets that do not dissolve directly, which are fed before the aquarium light is switched off, are ideal, as the crabs often need some time to look for food in the dark. If the animals cannot find food or if there is not enough food available, they attack fish and snails and eat them, and intraspecific aggression also increases. Cherax peknyi can be kept individually or in pairs (from 100 cm) in aquariums with at least 60 cm, with animals of the same size and requires a water temperature of 22 to 25 ° C.

supporting documents

Individual evidence

  1. ↑ Christian Lukhaup and Brett Herbert: A new species of crayfish (Crustacea: Decapoda: Parastacidae) from the Fly River Drainage, Western Province, Papua New Guinea. Memoirs of the Queensland Museum, 52 (2), pp. 213-219, Brisbane, April 2008

literature

  • Christian Lukhaup and Brett Herbert: A new species of crayfish (Crustacea: Decapoda: Parastacidae) from the Fly River Drainage, Western Province, Papua New Guinea. In: Memoirs of the Queensland Museum. 52 (2), pp. 213–219, Brisbane, April 2008 online: PDF ( Memento of July 11, 2009 in the Internet Archive ), (4.07 MB)

Web link