active carnivore baltic prawn, saltwater decapod crustacean in green ulva algae inspects sand bottom of original aquarium

active adspersus adult algae animal aqua aquaculture aquadesign aquarium aquascape aquatic background baltic biodiversity biotic biotope black bottom carnivore clear crustacean decapod decorative design discovery ecology edible environment fascinating fauna fishkeeping free friendly funny glass green inspects instinct invasion invasive life macro marine natural nature organism original palaemon pet prawn reef resistant saltwater sand sea shrimp space tank transparent ulva underwater vulnerable water widespread wild