Understanding how organisms communicate is a fundamental question in biology and marks an evolutionarily important milestone. Organisms largely communicate via gas-based gasocrine, light-based photocrine, and sound-based sonocrine signaling. Additionally, organisms signal via metal ions, compete for metal ions, and sense metal ions released by abiotic components. However, to the best of my knowledge, there are no specific unifying scientific terms to describe metal ion-mediated organismal communication or the sensing of metal ions from abiotic components. I propose metallocrine signaling to include not only metal ion-based communication between organisms but also between abiotic components and organisms. The sensing of metal ions may occur not only via membranal metal ion-sensing receptors, but also via non-membranal metal ion-binding proteins with various additional domains (protease, kinase, guanylate cyclase, transcription factor, etc.,). Metalloreceptors include zinc-sensing DNA-dependent RNA polymerase b in Escherichia coli, GTF3A/TFIIIA (General Transcription Factor IIIA) in vertebrates, and F-group bZIP transcription factors (such as bZIP19 and bZIP23) in Arabidposis thaliana. Metalloreceptors also include calcium-sensing fluorescent protein aequorin in Aequorea victoria and lithium-sensing RNA-based riboswitches in microorganisms. Whether metal ions in oxygen-producing photosystem II enzyme play an additional structural role requires further experimental validation. Finally, metal ions play an essential role in gas-sensing gasoreceptors, and hence, tightly regulated sensing of metal ions becomes a fundamental requirement for gasocrine-based organismal communication. This regulation is crucial for sustaining both animal and plant life.