Domain: Eukarya
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Delphinidae
Genus: Tursiops
Species: Tursiops truncatus
So long and thanks for all the fish!
Do you know the significance of the number 42? Bottlenose dolphins sing a song about Earth’s destruction; quick, ask them before they leave the planet!
The world’s about to be destroyed
There’s no point getting all annoyed
Lie back and let the planet dissolve around you
Never mind; the dolphins are too busy. Forty-two is the answer to the ultimate question of life, the universe, and everything—at least, according to the super computer Deep Thought and Douglas Adams in The Hitchhiker’s Guide to the Galaxy!
For me, this is the 42nd post on this blog, and I thought I’d be funny about it. So, no, the world is not going to end and all the bottlenose dolphins aren’t breaking out into song before jetting themselves out of the ocean and into space. If you haven’t seen the movie or read the books, I highly recommend them.
Now, let’s get back to our regularly scheduled programming!
The common bottlenose dolphin, Tursiops truncatus, is one of the most exposed dolphins in the world. They are very common in zoos and aquariums. They make appearances in movies or even star in them, like Flipper. They also like to hang around boats and can be seen close to the beach. When people think of dolphins, they usually imagine a T. truncatus.
Bottlenose dolphins are found in a variety of habitats around the world. Their distribution stretches from the temperate waters of the Northern Hemisphere to the temperate waters of the Southern Hemisphere. Local populations of the common bottlenose dolphin can be found along every continent but Antarctica.
Tursiops truncatus have a wide head and body, short stubby beak, long flippers, and a relatively tall dorsal fin. These dolphins have a crease between the beak and the melon that allows researchers to distinguish common bottlenose dolphins from similar-looking species, like the Rough-toothed dolphins.
The common bottlenose can be found inshore of most coasts, living in or near bays, estuaries, coral reefs, or even the mouths of rivers that link directly to the sea. Other populations of dolphins can be found offshore in deeper waters. Offshore bottlenose dolphins look a little different from their inshore relatives with thicker, darker bodies and shorter flippers, though genetically they are the same species.
Bottlenose dolphins are extremely sociable creatures, between themselves and other animals as well, including pilot whales and human swimmers. Despite their stereotypical friendliness, they have been reported to be unfriendly towards other species of dolphins. Along with acting sociable, dolphins emit a wide variety of clicks, squeaks, and squeals that they use to communicate with each other and other pods of bottlenose. Research suggests that each dolphin has a specific sound associated with it, like a name, that other dolphins use.
T. truncatus are highly intelligent creatures. Depending on their prey, the dolphins use various tools and techniques to catch their food. Some use echolocation, the emission of high frequency sound, to locate and confuse fish. Others have been seen rushing a school toward the shore, getting the fish nearly beached before the dolphins catch and eat them.
The diet of the dolphin changes depending on where the pod is located. For instance, inshore dolphins may have more crustaceans and shrimp in their diet while offshore bottlenose have more deep sea fish and squids in theirs. Bottlenose dolphins are remarkably adaptable, even to the extent of learning to identify fishing vessels and shrimp boats, and incorporating the fisherman’s actions into their hunting behavior.
Overall, their population numbers are good. The species as a whole is not a concern for extinction. Local populations, however, are decreasing due to viral outbreaks, weaker immune systems due to biotoxins and pollution, loss of habitat, and depleted fishing stocks. On a smaller scale, many local populations of inshore bottlenose dolphins need help.
When I first got interested in the ocean, I wanted to work with dolphins. In elementary school, I had a well-worn book on dolphins and sharks that was a companion novel to a Magic Treehouse book. I was so proud of it!
Now my focus has changed to coral, and I have a love/hate relationship with dolphins. I absolutely love dolphins; they are beautiful, intelligent creatures that want nothing more than to eat and play—and boy, do they play! However, sometimes I feel that they get too much attention from the public, and other sea creatures are hurt by it, as in the example of dolphin-safe tuna.
I don’t have time to get into the history and nuances of dolphin-safe tuna; I’ll leave that topic for a future post. The common bottlenose is one species that I’ve loved since I was a child. My biggest complaint is that dolphins get more empathy—because they are warm-blooded creatures like us—than any other creature in the ocean, except for maybe polar bears. This lack of human empathy toward cold-blooded creatures can have a negative impact on the ocean, and, ultimately, dolphins to.
Sources and links:
Ocean: The Definitive Visual Guide by the American Museum of Natural History
National Audubon Society: Guide to Marine Mammals of the World by Randall R. Reeves, Brent S. Stewart, et.al.
https://www.nationalgeographic.com/animals/mammals/c/common-bottlenose-dolphin/
https://kids.nationalgeographic.com/animals/mammals/bottlenose-dolphin/
https://www.fisheries.noaa.gov/species/common-bottlenose-dolphin
https://www.britannica.com/animal/bottlenose-dolphin
https://animals.net/bottlenose-dolphin/
Siren's Call to the Sea 