danube crayfish predator search food, european biotope aquarium, twig gravel disorder mess , hornwort plant

abdomen adaptable antenna appendage aquaculture aquadesign aquarium astacidae astacus background behaviour biotope bogwood buh camouflage carapace caught claw clearwater coldwater conditions controlled crayfish crustacean danube dark decapod design destructive disorder dof domesticated driftwood ecology ecosystem edible environment european exoskeleton fauna fishkeeping food freshwater gravel habitat hardscape harmful heteropoda hobby hornwort instinct invasive leptodactylus mess narrowclawed necrophage neocaridina nocturnal omnivore periopod plant predator river rostrum sand search shallow southern space temperate threat turkish twig underwater vegetation weed wild wildlife