Unlike many animals, sharks lack the ability to make any vocalizations. This is because they lack a sound-producing organ: the larynx. So, while they are able to make sounds, they cannot vocalize from the throat.
So, how do sharks communicate with each other if they cannot make vocalizations?
One such communication tactic is through the use of body language. Many species use body language to express their desire to mate. For example, grey reef sharks typically arch their backs to show dominance. In this display, pectoral fins point down, and the head is swung laterally, almost mimicking a clock pendulum.
Of course, body language for communication wouldn’t be possible without visual communication. Many shark species have exceptional eyesight, adapted to the oceanic hues of blue-green, low light conditions.
What about olfactory communication?
Another important way in which sharks communicate is by olfactory communication.
This is a form of communication by detecting chemical cues in the environment. Olfactory communication is essential for reproduction and the location of prey.
A plethora of chemical information, in the form of dissolved substance within the water, flow across chemosensory receptors. These receptors respond to organic compounds, especially those released by prey species. Sharks can detect this information and respond accordingly.
Similarly, receptive females will release chemicals and pheromones into the water to indicate that they are interested in getting a mate.
Different species communicate in slightly different ways to get the point across.
Some, such as hammerheads and great whites, have complex mating rituals.
Here, individuals display strength and dancing – like a typical Saturday night out. Most sharks, however, bite females to get their attention, often on their fins.
What is the “barking shark”?
Recent studies have investigated alleged theories of certain shark species “barking”.
Reports are few and far between, yet there is evidence that whale sharks emit a wave of grunts and groans.
This is a breakthrough discovery and may impact the way scientists study sharks.
Typically, sound vocalization is seen as a way of interacting socially with other group members. And while sharks are thought to be a solitary species, they show grouping tendencies – especially during the mating season and when food is in high abundance.
Are sharks solitary or social?
Once thought to be purely solitary animals, recent studies have questioned this fact.
Now, it is generally accepted that sharks can be both social AND solitary. Owing to certain environmental conditions, sharks can choose to be social or solitary.
For the most part, many species remain solitary.
Typically, sharks can be seen hunting and swimming by themselves, only joining other sharks at certain times, such as mating or migrating. The science on shark biology is continuous, and new data is constantly coming to light.
Sharks are fascinating yet complicated species to study.
To date, we still aren’t fully aware of shark biology and lifestyle. Some sharks form huge schools of over 100 individuals. Why they do this remains a mystery. However, it has been hypothesized they migrate to follow food or find cooler ocean temperatures.
Do sharks hunt together?
On rare occasions, some species have been known to hunt together cooperatively.
Species, such as sevengill sharks, group together to take down larger prey – much like other more familiar social species, such as orcas and lions. A favorite prey species, the fur seal, is often too large for an individual to take down. Instead, they communicate visually: when one shark attacks, the rest of the group follows.
This behavior has also been recorded in subspecies of great white sharks (Carcharodon carcharias). Individuals arriving at Seal Island, South Africa, form schools of up to 6 individuals. Similar to how a wolf pack behaves, each group has a leader and other ranked individuals.
How do sharks socialize?
A common way for sharks to socialize with one another is through aggression.
Although it sounds like a rather intense way to socialize, it is a form of communication to sharks within the vicinity.
This behavior is often deployed around times of fending, especially within a frenzied scenario.
Sharks displaying aggressive communication are effectively warning other sharks to stay away.
One of the most social species of sharks is the renowned great white shark. These large requiems show social hierarchy and dominance over subordinates. Following this structure, large great whites dominate smaller sharks, and females dominate males.
Interestingly, great whites have been known to form coalitions. After a bout of dominance, often through aggressive communication, they have been recorded to show an interest in one another. In simple terms, they make friends with each other and often travel around in pairs.
Some species of sharks have been likened to social mammals such as dolphins and elephants.
One such species is the Sand Tiger shark. This species displays a fission-fusion society; whereby they hunt solitarily and then return to a family group.
In conclusion, much of our prior knowledge about the sociality of sharks is questionable.
Novel studies are revealing new insights into the social behavior of sharks. What we thought to once be lonesome killing machines are simply misunderstood creatures with an interesting life history.
Sharks communicate in various ways, including olfaction, body language and visual cues.
Some sharks are social and intelligent, forming societies and hierarchies.