Common Bottlenose Dolphin

A pair of bottlenose dolphins (Tursiops truncatus) swim beneath the surface. Sandy Ridge, Little Bahama Bank. Bahamas. Photo taken by Dr. Alex Mustard, more can be found at www.amustard.com

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/

Humpback Whale

Humpback whale jumping out of the water. Photo taken from pexels.com

Domain: Eukarya
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Balaenopteridae
Genus: Megatera
Species: Megatera novaeangliae

When we speak, hum, sing, etc. we make those noises by vibrating our vocal cords. Sometimes, when you hum or hold a note, you can even feel the vocal cords in your throat. Whales can also sing. In fact, male humpback whales sing to communicate and can be heard for miles by other whales, each “song” lasting up to about 30 minutes.

Fun fact: scientists don’t know how humpbacks pull off singing, because they have no vocal cord.

Humpback whales get their common name from the way they arch their back when diving. They aren’t the largest or heaviest whales in the world, but they do have the longest flippers. Their fluke and wing-like flippers can help you identify the whale as a Megatera novaeangliae, and the unique white splash-like markings on those appendages allow scientists to distinguish between individuals, like a fingerprint.

These creatures can be found in all of the world’s oceans, in both tropical and polar regions, though they don’t venture too far up into the poles.

M. novaeangliae are a type of baleen whale, meaning that they don’t have teeth like we do, and they take in large amounts of water that, hopefully, contain a lot of krill and small fish. Humpback whales are different from other baleens because they can actually trap their prey through a process that is better to watch in a video or documentary (e.g. Blue Planet).

When humpbacks find swarms of krill or schools of small fish, they will try to gather them together. They do this by exhaling air while they spiral around their prey. This action creates a “bubble-netting” that confuses and traps the prey, allowing humpbacks to dive below and lunge upward to feed upon their prey. Like I said, I highly recommend watching this on a video or a documentary because it’s incredible to see, and if you get a chance to see it in person, all the better!

I feel like humpback whales are underappreciated. I first learned about them when I started watching nature documentaries in high school, but it wasn’t until college that they started getting more fleshed out in my mind.

They’re amazing creatures that produce eerily beautiful songs. I should know; I had to listen to some in a lab class in college, and they have a unique feeding behavior for baleen whales. While they’re not endangered or threatened, their populations have been reduced to a fifth of what it once was due to whaling practices—that’s mind-blowing to me!

If what you’ve read has piqued your interest, please take the time to learn more about these creatures. There’s so much that I couldn’t add, and who knows, maybe your curiosity will lead you into a job that will allow you to understand the mysteries of their singing.

Videos of bubble netting:

Sources and more reading:
Ocean: The Definitive Visual Guide made by American Museum of Natural History
Ocean: A Visual Encyclopedia made by the Smithsonian
Marine Mammals Evolutionary Biology 3rd edition by Annalisa Berta, James L. Sumich, and Kit M. Kovacs
https://animaldiversity.org/accounts/Megaptera_novaeangliae/
https://www.chesapeakebay.net/discover/field-guide/entry/humpback_whale
https://oceanwide-expeditions.com/to-do/wildlife/humpback-whale
https://www.nationalgeographic.com/animals/mammals/h/humpback-whale/
http://wildwhales.org/speciesid/whales/humpback-whale/
https://www.fisheries.noaa.gov/species/humpback-whale
https://us.whales.org/whales-dolphins/species-guide/humpback-whale/

Jackass/African Penguin

Photo by Jean van der Meulen from Pexels

Domain: Eukarya
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Sphenisciformes
Family: Spenisciformes
Genus: Spheniscus
Species: demersus

First, I would like to clarify that this penguin has two accepted common names, Jackass and African penguin, and I’m not just cursing just for the fun of it. The two common names are used to describe unique features of this species of penguin.

This species is known as the African penguin, because it lives on the coasts of South Africa and in the south Atlantic and southern Indian oceans. It’s lovingly called the Jackass penguin because when it calls out for a mate it sounds like a braying donkey, and the name “Donkey penguin” just doesn’t roll off the tongue. Seriously though, take the time to watch videos of these guys’ mating calls—it will make your day!

Not all penguins live in arctic climates. The African penguin has adaptations that allow it to survive the cold temperatures of the oceans and the sweltering heat of Africa. It has a dense coat of feathers that keeps it warm and water proof. For the hotter weather, its pink glands above the eyes collect blood that is then cooled by the surrounding air to help keep the penguins from overheating.

Jackass penguins grow no bigger than about two feet tall, making them one of the smallest penguin species. It looks very similar to its South American cousin, the Magellanic penguin, but instead of having two black bands on its chest, the jackass penguin has only one black band.

Another cool feature about these guys is that each individual display a unique flecked pattern on its feathers that acts like a fingerprint. Each pattern is unique and allows researchers to keep track of who is who. Jackass penguins can hold their breath for up to 2‒3 minutes and can dive down to 400 feet to catch small fish such as anchovies and sardines, small squid, and crustaceans. African penguins are also really good parents, even if they keep their eggs in nest made of guano (seabird and bat poop). They don’t always mate for life but they stay together through incubation, hatching, and raising.

I’ve liked penguins ever since I was little, but they were never really a main focus of my affections. Penguins are still interesting to read about because each species has their little quirks, like these guys that sound like braying donkeys when they’re looking for a lady. I highly recommend taking the time to read up on these penguins’ they’re the only species of penguin in Africa, and they’ve been declared to be endangered. There are already programs in place to help protect this species, but even that can’t completely stop the overfishing of their food sources.

Penguins braying like donkeys:

Sources and cool links:
Ocean: The Definitive Visual Guide made by the American Museum of Natural History
https://www.biologicaldiversity.org/species/birds/penguins/African_penguin.html
https://animalfactguide.com/animal-facts/african-penguin/
https://oceana.org/marine-life/seabirds/jackass-penguin
https://animals.sandiegozoo.org/animals/african-penguin

Sea Otters

Photo of a Sea Otter taken by Dave Bezaire & Susi Havens-Bezaire

Domain: Eukarya
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Mustelidae
Genius: Enhydra
Species: Lutris

Today we’re going to discuss sea otters! These adorable carnivores can be rather cool to read about, especially when you get into behavior, adaptations, and their ecological role in their environment.

The sea otter is the only otter that can spend its whole life in the ocean, all other otter species dwell near the water for resources but lack the adaptations needed to live in the water. One such adaptation is their fur in sea otters, which was highly coveted by fur traders a century or more ago because of how dense it was.

In fact, they have the densest coat of all mammals, their hairs are so tightly packed that water can’t penetrate, keeping them nice and dry in the cold Pacific waters. And while all the other mammals are jealous of their glorious fur, the sea otters need it because they lack any real fat to help keep them warm.

These guys can be found along the coasts of Japan, Alaska, and California and especially near kelp forests. Enhydra lutris are what we call a keystone species because of their massive impact on the kelp forests, which I’ll discuss in a later post.

Sea otters are carnivores that feed on crabs, sea urchins, and mollusks. They can dive up to 40 meters to grab food that they bring to the surface, and then they use a stone to crack open shells and other protective covers so they can get at the meat inside.

I know what you’re thinking, if these guys can’t breathe underwater how do they sleep? Well, they use the giant kelp around them to help prevent them from drifting out to sea with the ocean current. They also live in communities with other sea otters, making them social creatures. When they need to rest they’ll form groups called rafts, and they’ll hold onto each other to keep their friends and baby otters from drifting out to sea—cute, right?

Like I’ve said earlier, there is so much more to sea otters than I can discuss in a single post. If I’ve piqued your interest, then I highly recommend looking at the links I’ve provided below! They’re cool mammals that use tools to help them with food and survival, and they’re also extremely adorable to watch. If I could do several more posts about sea otters I would, but that wouldn’t be very fair to the other sea creatures that are incredible in their own right!

Sources and cool references to check out:

Ocean the Definitive Visual Guide by the American Museum of Natural History
https://animaldiversity.org/accounts/Enhydra_lutris/#food_habits

https://www.montereybayaquarium.org/animals/animals-a-to-z/sea-otter