cerianthus membranaceus long blue tentacles to hunt for plankton food, popular fluorescent pet in actinic led light

tube dwelling anemone cerianthidae cylinder mediterranean sea semiburied invertebrate sting crown whorl cnidocyte stinging cell nematocyst labial tentacle oral disc retract photosynthetic nocturnal dim light biodiversity biocoenosis fauna sealife environment wildlife aggregation community salt saltwater aquatic aquascape hardscape reef tank aquaculture current tropical coral controlled conditions captive cultivation understanding nature toxic poison venomous ecology hardy bottom habitat balance aquarium trade glass refraction