The gastropods, also known as snails and slugs, are members of the Gastropoda taxonomic class of invertebrates within the phylum Mollusca. A gastropod's radula is usually suited to the food that the species consumes. Limpets and abalones are the most basic gastropods, herbivores who utilise their strong radula to rasp at seaweeds on rocks. Burrowers, many marine gastropods have a syphon that extends from the mantle edge. To accommodate this structure, the shell may have a siphonal channel. The animal uses a syphon to suck water into their mantle chamber and across their gills. They mostly use the syphon to taste the water and find prey from a distance. Gastropods with syphons are typically predators or scavengers. Gastropod sensory organs include olfactory organs, eyes, statocysts, and mechanoreceptors. Gastropods cannot hear. The olfactory organs, which are placed on the tips of the four tentacles in terrestrial gastropods, are the most significant sensory organs. Rhinophores are the chemosensory organs of opisthobranch marine gastropods. The peripheral nervous system and the central nervous system are the two sections of snail neurological systems. The central nervous system is made up of ganglia connected by nerve cells.