narrow-clawed crayfish climb on front glass, show belly, claw, tail on sand gravel, hornwort planted biotope aquarium, wild caught

astacus leptodactylus danube crayfish turkish astacidae rostrum telson periopod antenna exoskeleton crustacean appendage decapod molting harmful nocturnal cultivation domesticated aquaculture underwater clearwater weed ceratophyllum demersum driftwood sandbed predator omnivore necrophage nature ecology threat unusual fauna widespread aquadesign water wildlife temperate edible instinct behaviour controlled conditions ecosystem organic pollution habitat european hardscape destructive space environment biodiversity substrate narrow-clawed climb front glass show belly claw tail sand gravel hornwort planted biotope aquarium wild captive freshwater species adaptable invasive animal background