danube crayfish predator camouflage, cherry shrimp, european biotope aquarium, twig gravel disorder , hornwort

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