The correct option is 1: Apple snail The statocyst is a specialized sensory organ responsible for maintaining equilibrium, balance, and spatial orientation, and its presence is a characteristic feature of many invertebrate phyla, including Cnidarians, Platyhelminthes, Annelids, Crustaceans, and Mollusks. The Apple snail (Pila globosa), a representative of the class Gastropoda within the phylum Mollusca, possesses a pair of sac-like statocysts located near the cerebral ganglia. Each statocyst is a…Read More