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Save the crucian carp!

The crucian carp - formerly one of the most common fish in ponds and village ponds...

The crucian carp

formerly one of the most common fish in ponds and village ponds...

The crucian carp (Carassius carassius) used to be one of our most common fish species. It was abundant in village ponds, oxbows and pools around rivers, often remaining the only species in stagnant water with a lack of oxygen and the last species in a clogged tank or pool. In fact, it is a master at surviving inhospitable conditions where other fish species die during oxygen-deficient periods. It can switch to an anaerobic (oxygen-free) metabolism for long periods of time, and thus survive even in muddy pools covered with ice and snow, where oxygen runs out for long periods in winter.

... today on the verge of extinction

In recent decades, however, strong competition has emerged for our native crucian carp. The gibel carp (Carassius gibelio), which, thanks to its similar resistance and ability to reproduce by gynogenesis (a form of asexual reproduction), managed to completely displace the crucian carp from its habitat, along with other species of animals, such as amphibians. Another threat to the crucian carp is the invasive topmouth gudgeon (Pseudorasbora parva) or very intensive use of village ponds for aquaculture.

About the crucian carp

About the life of the crucian carp

Dive with us into the world of the crucian carp, a fish full of mystery and amazing adaptations. Discover its food preferences, secret hiding places and everything about its life and ecology. Find out how important it is to our aquatic ecosystems and why it is so......

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Causes of the threat

There are basically three causes for the decline of the crucian carp: straightening of rivers to compensate for annual fluctuations in their flows, intensification of management in riverside ponds and invasive fish species....

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Recognising species of Carassius can often be a challenging task, especially if they resemble or live in the same aquatic environments. The crucian carp (Carassius carassius) has distinctive features that set it apart from other fish species....

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Help us find suitable places to save the crucian carp

Although it is generally known that the crucian carp is now on the verge of extinction, their decline, especially in local village ponds and quarries, has not yet been fully mapped. In fact, unlike selected streams and reservoirs, these waters are generally not monitored at all.

Our goal is to find places to focus on to save it:

  • Identify suitable remnant populations of the crucian carp to be used for their return to the landscape
  • to find suitable sites for the introduction of the crucian carp
  • to map the distribution of the crucian carp in the Czech Republic

Together for a good cause