5 Dolphin Trivia
Dolphins are exceptional animals because their great cognitive development, their aquatic abilities or their ability to keep swimming while they sleep make them incredible beings. However, they may surprise us even more: as they always live underwater, there is still a lot to know about these cetaceans.
Currently, 37 different species of dolphins are known, and the vast majority inhabit the planet’s seas and oceans, but there are some freshwater species. If you want to know some quirks about these fascinating animals, read on.
How do dolphins live?
Dolphins are cetacean mammals that give birth to young in open water and have long periods of lactation. They are fully adapted to marine life, but remain ectothermic mammalian vertebrates despite their shape and living habits.
They live in groups and are very social and communicative animals. In addition, they use a series of high-pitched squeaks and whistles to communicate between members of society – and mothers with their babies. These animals have a sophisticated echolocation system that helps them locate other individuals, prey, or get an idea of what’s in their path.
They are excellent swimmers, managing to reach speeds greater than 30 kilometers per hour in open water. During their movements, they surface to breathe 3-5 times a minute, although they can hold their breath for up to 10 minutes straight.
This is their general way of life, but there are many other curiosities about these cetaceans. See below 5 of the most relevant characteristics that characterize them.
1. Dolphins sleep with half their brains awake
How do dolphins manage to sleep and keep breathing in water? The answer lies in the uni-hemispheric dream presented by aquatic mammals and birds. There is an alternation between both cerebral hemispheres, which allows these animals to fully rest while breathing and swimming – or flying – at the same time.
With only one hemisphere of the brain asleep, the other remains conscious enough for the animal to rise to the surface in search of oxygen. Added to this peculiarity is the fact that they sleep with only one eye open, the opposite of the awake hemisphere.
2. They use “tools”
Years ago, a curious behavior was observed in some dolphins in the Australian Shark Bay. These cetaceans appeared every day carrying a sponge in their snout.
After thoroughly investigating this behavior – where they performed it and for what purpose – researchers Eric M. Patterson and Janet Mann, from Georgetown University (USA), concluded that dolphins used sponges as protection to dig into the sea floor in search of of his favorite prey, the Parapercis nebulosa fish .
This trick allowed them to specialize in fishing for this species, which other predators, including other dolphins that share the bay, do not have access to. As if the ability to use tools were not enough, this knowledge is socially transmitted, since the chicks learn from their mothers this unique technique of hunting fish.
3. Dolphins have the best sonar in the animal kingdom
In the dolphin’s head is the organ it uses for echolocation, thanks to which the animal can know about its surroundings by emitting sounds and interpreting the echo that bounces off the elements around it. Dolphins emit sounds at a frequency of 120 kHz.
Also, these cetaceans are known to have great hearing. While humans’ excellent hearing ranges from 20 Hz to 20 kHz, dolphins are capable of hearing up to 150 kHz, meaning they have up to 7 times more sensitive hearing than ours.
4. They have proper names
The dolphins’ communication system is very varied, they even use specific whistles to identify themselves and other members of the group.
As visibility in the ocean is reduced, sound is the best way to convey messages. Therefore, receiving information in this way and knowing “who is there” is essential for your survival. The concept of identity is present in many other species of social animals, for example birds, but it is still surprising.
5. All your teeth are the same
Dolphins are isodontic animals, that is, all their teeth are exactly the same, but in the case of dolphins they are not used to chew, but to retain the fish they catch before swallowing. Dolphins have a total of about 250 teeth.
They often work as a team to hunt among large schools without scattering their prey. They are carnivorous predators, as their food is based on other animals, usually fish, squid, crustaceans and even octopuses. They are also often seen chasing fishing boats in search of the waste they throw into the sea.
As you have seen, dolphins are animals worthy of admiration. Their physical abilities, their behavior, their communication and their group relationship are still aspects studied in depth today, as there is still a lot to learn from them.
