The signal crayfish "Pacifastacus leniusculus, Ecrevisse de Californie Lac du Bourget_2 (pêche INRA automne 2017)" by photonat3873017107 is licensed under CC BY-NC-SA 2.0

Crayfish (Astacoidea spec.)

Invasive?

Orconectes limosus, the Spiny-cheek crayfish and its congeners Pacifastacus leniusculus, the Signal crayfish and Procambarus fallax, the Marbled crayfish all originate from North America and nowadays inhabit almost all flowing waters. They are carriers of the deadly fungus "crayfish plague", to which they themselves are resistant. Since the crayfish grow faster, reproduce more strongly and are much more aggressive, they are biologically superior to the native European crayfish Astacus astacus and displace it even without transmission of the crayfish plague. Since the signal crayfish is very similar to the noble crayfish, it has also been released by humans into various lakes.

Where?

The crayfish are quite shy, which is why you can often only spot dead animals or moulting carapaces. Being nocturnal animals, they like to stay hidden in their hiding places or among aquatic plants during the day. They are omnivores. Both crayfish prefer cool rivers, but can also cope with warmer still waters.

Appearance?

 

The signal crayfish - Pacifastacus leniusculus

Signalkrebs

Signalkrebs1

Are brownish to olive, carapace smooth. On the upper side of the claws at the joint there is a turquoise-white signal spot (name!), which is sometimes only weakly pronounced or even missing. The undersides of the claws are red.


Distribution in Luxembourg: https://neobiota.lu/pacifastacus-leniusculus/

Please report the species if you have seen it via the website link.

 

 "Pacifastacus leniusculus, Ecrevisse de Californie Lac du Bourget_1( pêche INRA automne 2017)" and "Pacifastacus leniusculus, Ecrevisse de Californie Lac du Bourget_2 (pêche INRA automne 2017)" by photonat3873017107 is licensed under CC BY-NC-SA 2.0.

The crayfish - Orconectes limosus

Kamberkrebs

Are brownish to olive in color, characteristic are the spines on the cheeks in front of the nuchal furrow and the orange tips of the claws.


Distribution in Luxembourg: https://neobiota.lu/orconectes-limosus/

Please report the species if you have seen it via the website link.

  

"Spinycheek crayfish" by Ansgar Gruber is licensed under CC BY-SA 2.0

 

The marble crayfish - Procambarus fallax

Marmorkrebs

The marbled crayfish has a smooth carapace and is marbled. These patterns are often unique per individual.

"Marmorkrebs Lorenz Seebauer SingliserSee Germany" by Lorenz Seebauer is licensed under CC BY-SA 4.0.