The ocean is saturated with sound, a marine soundscape where countless species rely on acoustics for navigation, feeding, and social interaction. Manta rays, with wingspans up to 23 feet, glide through this environment with grace. These rays exhibit complex social behaviors and possess the largest brain-to-body ratio of any fish. This intelligence leads many to wonder whether they contribute to the chorus of the deep, and if these large animals make intentional sounds.
The Biological Capacity for Sound
The definitive answer to whether manta rays are vocalizers is no, as they lack the specialized anatomical structures required for intentional sound production. Manta rays are cartilaginous fish (elasmobranchs), unlike bony fish that produce sound using a swim bladder or specialized sonic muscles. Mantas lack these organs, which are typically used to create communicative clicks, grunts, or pops.
Intentional sound production requires a mechanism for generating and modulating sound waves, which is absent in manta ray anatomy. Mantas have no vocal cords and no internal structure that could generate a purposeful signal. Their internal structure is optimized for filter-feeding and hydrodynamics, not acoustic signaling.
Anecdotal observations have suggested the possibility of rare, non-vocal sounds, such as clicks or squeaking noises potentially caused by the grinding of their jaw structures. These instances are not considered evidence of a developed acoustic communication system. No systematic study has ever recorded a mobulid ray producing a consistent, communicative call, and the scientific consensus is that they are acoustically silent.
Incidental Noise from Physical Activity
Although manta rays do not vocalize intentionally, they generate extremely loud, incidental noises through powerful physical actions. The most dramatic noise occurs when the animals breach, or leap completely out of the water. A giant oceanic manta ray, which can weigh up to two tons, creates a thunderous sound when its massive body crashes back onto the ocean surface.
The purpose of breaching is not fully understood, but the resulting sound is clearly audible for long distances underwater. Possible explanations include a social function, such as signaling other rays, or a means of removing parasites. The volume of the impact suggests it is a high-energy signal intended to be perceived across a wide area.
A similar, less explosive, incidental noise is created when manta rays aggregate for feeding. As dozens of rays perform synchronized maneuvers, the hydrodynamic noise from their massive fins flapping and mouths scooping water can be significant. This collective sound contributes to the local soundscape but is a byproduct of their physical presence, lacking the intentional modulation of a communicative signal.
Communication Without Acoustics
Since manta rays are not acoustic communicators, they rely heavily on other senses to navigate their complex social lives. Their intelligence and social nature are demonstrated by their use of specific visual and gestural cues to interact with one another. A primary method involves the movement of their cephalic lobes, the fleshy, horn-like fins on either side of their mouth.
Researchers have observed that mantas move these modified pectoral fins in specific ways during social encounters, suggesting a form of gestural language. For instance, small flicks of the lobe tips are frequent when a ray faces another individual, while a tight rolling of the lobes is associated with being followed. These movements are believed to be used for social communication or to attract the attention of cleaner fish at cleaning stations.
Tactile interaction is also a component of their social behavior, particularly during mating sequences. Courtship involves a “mating train,” where multiple males pursue a single female. The successful male grips the female’s pectoral fin with his mouth to secure a position for mating. Manta rays also possess a keen sense of smell, suggesting a potential role for chemical signaling, such as pheromones, in detecting mates or food sources.