The idea of a shark purring is purely fictional. Sharks do not purr because they lack a larynx, the organ mammals use to create sound. Instead of vocalizations, sharks rely on a sophisticated combination of silent body language and highly refined, specialized senses to navigate their environment, locate prey, and interact with one another.
The Truth About Shark Vocalization
Sharks are largely silent hunters because they lack vocal cords, a larynx, and the swim bladder many bony fish use to amplify sound. Consequently, they cannot produce intentional, communicative calls like the whistles of dolphins or the songs of whales. Any sounds associated with sharks are incidental to their movement or feeding activity, such as a tail slap or the clashing of teeth. Some species, like the rig shark, have been recorded making clicking sounds by rapidly snapping their teeth together, but this is typically a reaction to disturbance.
Communication Through Body Language
Since they cannot vocalize, sharks communicate their intent through visual cues and body posture. This silent communication system is important for establishing a social hierarchy and signaling aggression or mating interest. When a shark feels threatened or territorial, it may perform an agonistic display to signal a warning.
A clear sign of annoyance is the “hunch” display, where a shark arches its back and lowers its pectoral fins. This behavior is designed to make the shark appear larger and more formidable, often serving as a final warning before a defensive strike.
Other forms of non-vocal signaling involve specific swimming patterns, such as parallel swimming, where two sharks swim side-by-side to size each other up and establish dominance. Dominant individuals may also assert their position by swimming higher in the water column or by “piggybacking,” where one shark physically pushes another deeper. In reproductive contexts, males of some species will bite the female’s back or fins to hold her during mating.
The Silent Sensory World of Sharks
The absence of vocal communication is compensated for by an array of non-vocal senses that allow sharks to perceive the world in a way humans cannot. One of the most unique is electroreception, facilitated by specialized organs called the Ampullae of Lorenzini. These tiny, jelly-filled pores are concentrated around the shark’s head and snout, connecting to sensory cells.
The Ampullae of Lorenzini are so sensitive they can detect electrical fields generated by the muscle contractions and nerve impulses of living prey. This allows the shark to locate fish buried under sand or to make an accurate strike even when visibility is poor. Electroreception also functions as a navigational tool, enabling sharks to detect the Earth’s geomagnetic field, which helps them orient themselves during long-distance migrations.
Sharks also possess the Lateral Line System for detecting movement and pressure changes in the water. This system consists of a row of sensory pores that run along the length of the shark’s body. Within these canals are specialized cells called neuromasts, which contain tiny hair-like structures.
When water movement or vibrations displace these hairs, the neuromasts send signals to the brain. The Lateral Line System effectively gives the shark a sense of “distant touch,” allowing it to detect the direction and speed of water flow. This sense is vital for detecting prey at a distance and for avoiding obstacles. The shark’s sense of smell, or olfaction, is also exceptionally strong, allowing them to detect minute concentrations of chemicals from great distances.