Tag Archives: diving

Perfect Ten

DSC08062

I’ve mentioned how penguins are pretty special birds, but I couldn’t resist posting again about their incredible adaptations as swimmers. On land they strut and waddle and trip and jump and generally look adorable and a little bit ridiculous… but as soon as their flippers strike the water, they transform.

Here’s a list of the ten coolest penguin adaptations/exaptations that allow them to swim like Olympic champions (or significantly better, sorry Michael Phelps…) in order of crazy awesomeness (aka no particular order):

1. Penguins are fat. Literally, according to NatGeo Wild and a study on Adelie penguins, the different species are all over 1/3 fat when they begin the breeding season. Although they lose much of this fat between feeding trips (King penguins can lose 50% of their body weight in a few weeks), the remainder helps insulate the birds from the extremely cold water.

2. Penguins are not fuzzy. The key to warmth in dry places is trapped air, and it’s the same in the water. But this means that penguin chicks (don’t worry, more photos to come) with their fluffy feathers don’t do so well when the feathers get wet. Meanwhile, adult penguins spread a greasy covering from a gland near the tail over their overlapping and interlocking body feathers that effectively waterproofs the birds’ internal coats of down, very analogous to our expedition’s giant orange coats over many layers of polar fleece. But as the penguins dive, they must feel the cold more and more as the limited air in their feather coat compresses and becomes a less effective insulator, much like human divers in their wetsuits and drysuits (Hi Justin and Erin!). They can’t keep too much air in their feathers or they’ll be too buoyant to dive. What they need is heated undergarments.

3. Penguins are countershaded. While the dark-on-top light-on-bottom coloration makes them look awfully dapper, penguins likely also use this coloration for heat regulation on land and camouflage at sea. Looking up at white bellies or down at black backs is more difficult for predators, allowing penguins to blend in just a little with the sky and darker ocean depths. This may also help them catch their prey.

4. Penguins hold their breath. Emperor penguins can dive for over twenty minutes, rising to the surface with blood oxygen levels so low that other animals would have passed out or experienced tissue damage well before they reached the open air. Not all penguins are so deep-diving- some average dives of thirty seconds or so- but all penguins have increased hemoglobin and myoglobin in their blood and tissues to help store oxygen.

5. In terms of oxygen efficiency, it also doesn’t hurt that penguins can regulate bloodflow to the exposed parts of their bodies (extremities like feet and wingtips, bare patches of skin on the face, etc.) as the water chills those body parts and slows metabolism and oxygen demand.

6. Speaking of blood, a penguin’s veins wrap around their arteries, transferring heat into the arterial blood and conserving as much of that precious internal body temperature as possible.

7. Penguins are streamlined. This doesn’t require much explanation- they’re like little well-dressed torpedoes, heads shrunk into shoulders and feet stretched back near the tail for steering and maneuverability.

8. Penguin wings are no good for flying, obviously- too tiny and stiff. But they’re AWESOME flippers underwater, attached to strong breast muscles to beat against the dense cold water. Penguin breast bones are very impressive. The photos I have of penguin bones are sort of gruesome, so I won’t post them, but you can search for them if you want.

9. Penguins can drink salt water! I know I’ve talked about this before, but I still think it’s really cool that they have a special gland for removing much of the salt out of ocean water. They just sneeze it out and continue about their badass way.

10. With such stubby wings, penguins already couldn’t fly. But with no need for lightness of body and a good incentive to dive deep, penguins have evolved away from hollow bird bones to solid bones, dense and sink-y.

Clams

Hello beloved readers!

I apologize most heartily for my relative absence- we’re wrapping up the field season here in Exmouth, with all that entails: extra snuck-in snorkel trips, boat cleaning, taking posters and papers off of the walls, last-minute photo-ops on the water, cooking strange combinations of things from the remnants of our kitchen cabinets… It’s been a bit of a whirlwind. But still fun, of course.

As a metaphor for my lack of posting, here are a series of photos of giant clams.

P1080882

The color in the mantle (the soft part, showing from inside the two shells) comes from algae that the mollusk can cultivate within its own tissue. The algae and the clam’s own filter feeding both provide it with food/energy.

P1080914

Giant clams like these can live up to 100 years in the wild, building up layers of thickening shells as they go.

P1080941

Just so that nobody emails me with warnings that these animals should be added to my list of Things-In-Australia-That-Want-To-Kill-Me (Wikipedia: “It was known in times past as the killer clam or man-eating clam, and reputable scientific and technical manuals once claimed that the great mollusc had caused deaths; versions of the U.S. Navy Diving Manual even gave detailed instructions for releasing oneself from its grasp by severing the adductor muscles used to close its shell.”) I’m pretty sure that I’d have to be trying to climb inside of one of them for it to even give me a good pinch. Most can’t even close their shells the whole way, nor would they have any desire to hang on to a snorkeler/diver. They’re about as dangerous as rotting logs. But much prettier.

Creature Feature

Basically the point of this post is that I think this photo is pretty funny, and I spent a fair bit of time combing through Gerald Allen’s Marine Fishes of Tropical Australia and South-East Asia trying to figure out what this fish was. I also got significantly closer to this one than to the stonefish that I posted about a while back,

IMG_1063

without being quite aware that it, bug eyes and pouty face and all, is listed on the University of Melbourne’s “Australian Venom Research Unit” page, with the description: “It is armed with two pairs of spines – two on its back and two on its sides. Despite its commonness, stings are infrequent and little is known about the effects of envenomation by this species, apart form (sic) the severe local pain experienced by the victim.”

IMG_1050

How reassuring. You’ve done it again, Australia, and hidden a painful surprise within a fringy funny-looking underwater friend. At least this one isn’t deadly, or at least not to humans. Halophryne diemensis (probably) translates roughly to “banded salt-toad,” and like a toad this fish, the banded frogfish springs upon its prey with unexpected speed from a cumbersome head and body, but didn’t seem at all interested in the many divers who passed right overhead.

This post is dedicated to my beloved readers Ben, Camille, and Isabella, who are welcome to choose any topic or question they’d like discussed in a post! Thank you so much to everyone who puts up with my lame jokes and biological ramblings, and especially to everyone who has donated to the Vicky-Has-Internet Fund- all of your support is thoroughly appreciated.

All Predators Are Super Scary

They come in all shapes and sizes. Below the Navy Pier (built by Americans here in Exmouth, to support the construction of the lovely VLF, aka Very Low Frequency, radio towers that you may see poking out of photos of the area), there are some big ones. The Big Friendly Grouper, rumored to have been desirous of chin rubs and head pats since the 1960s or so, is perhaps the most obvious of the large predators. Though he lives up to his name with regard to divers, the BFG could still suck down some pretty big fish if he so chose. The Wikipedia page for Queensland groupers, of which he is one, states that they consume a large variety of marine life including “large sharks and juvenile sea turtles.”

Yeah, I dunno. Large sharks? Whatever. We gave his giant green-gray dorsum a good pat on the sand near the pier and moved on- I’ll see if I can get some photos from my dive buddy, because at that point my poor little camera had sucked down a bit too much salt water.

Our next predator, though, was much more colorful, and just a bit smaller:IMG_1077

 

The photo’s not my best by any means, but these little colorful guys (Harlequin shrimp snacking on an unfortunate sea star) were tucked in among what appeared in low light to be gray-blue-green rocks, and I had to hang a bit upside-down and change my white balance to get it. Perhaps the shrimp don’t seem as intimidating as other predators I’ve mentioned on this blog, but that’s only because you don’t move solely on tube feet. To this sea star, they’re the scariest thing on six legs. 

My third and final predator for this post:IMG_1037

 

The greynurse shark (Carcharius taurus) is known to be non-aggressive… unless provoked. Happily nobody in our dive group was interested in provoking anyone or anything, and for the most part the little sharkies (2-3m, maybe 6-9 feet?) took very little notice of us at all. With the visibility under the pier, maybe 8-10 meters maximum, it was very easy for them to slip out of view, which was a bit disconcerting, but thrilling nonetheless. The most archetypal predator, lurking in the murky depths, gliding without effort through the jumbled wrecks of past and sunken human endeavors… You don’t notice until you get to see one up close, but they’re all fine-tuned muscle, tough cartilage, and suspicious eyes balanced and perfectly buoyant in the water. And you look at them, bubbles spewing from your regulator and pooling against the underside of the rusting beams over your head, bobbing up and down each time you breathe, hands shaking (from cold, of course) and bright plastic fin tips brushing the rubble below you, and you wonder how little soft pink humans ever got to think they were in charge of the world.

You Won’t See It Coming

About once a week, maybe more, I get an email from someone I know (relatives, friends), with a title something like “340 Things That Will Kill You In Australia Without You Knowing” or “54.3 Ways Australia Secretly Wants You Dead” or “How To Get a Job and Stop Being a Drain on Earth’s Resources” (wait crap that last one is unrelated). Anyways, there are apparently lots of poisonous things that want me dead on this continent, though so far they’ve been reluctant to go on the attack. Anyways, part of what freaks people out about Australia I guess is the number of things that are both poisonous and sneaky.

Enter the wobbegong- this Eucrossorhinus dasypogon is considered harmless (I’ll start you off easy) if unprovoked, but certainly startling to come upon. The Navy Pier at Exmouth (dive currently run by the Ningaloo Whale Shark and Dive Company, very fun crew, very cool dive!) hosted at least two different and fairly large wobbegongs, which was excellent- they’ve been on my list of cool fishes since I was a young Agent Red Squirrel, reading books about marine life under the covers late at night. It’s harmless to divers but looks sort of creepy- those white spots aren’t actually the eyes, though. Look closer:

IMG_1035

 

 

 

But only because you’re a human- if you were a fish, you wouldn’t want to get that close. That wide mouth creates a lot of suction, and technically that fluffy carpet there IS a shark.

More fun facts about the tasseled wobbegong- its fringe is made of skin, and in the other two species of wobbegongs doesn’t go all the way around the chin. That’s why this name (Eucrossorhinus dasypogon) translates to “well-fringed nose with shaggy beard.”

 

All right, now that you’re nice and comfy down there under the pier, keeping a close eye on where the beams and columns are relative to your head but making plenty of time to listen to the humpback whales singing in the distance and look at the schools of silvery fish drifting through the beams of light in the cloudy water, take a look just off to the north:

 IMG_1063

Stonefish, like this Synanceia horrida (see, aren’t Latin names fun?) can kill a grown man with one stab of their venomous and invisible spines. Happily, I’m no grown man and can therefore get a lot closer in… just kidding, Mom. We kept our distance and used the zoom on our cameras, but I was terribly impressed by our dive guide, Wes (who is moving to London and had a touching farewell with another lovely friend under the pier, who I’ll tell you more about later) for spotting this guy in the first place. Even pointed out, photo-enhanced and zoomed in, the fish still looks like nothing much. That was the part of the dive when I was happy that all of my various dive instructors and buddies and wise old advisors had taught me to keep my arms in close, away from stingy and bitey hidden bottom-dwellers.

I love diving- even without my favorite dive buddy, I had a happy and safe (though a bit chilly) time under the man-made and ocean-encrusted pier that we see so often from our transects. Warning to photographers, though- don’t take your favorite camera, even in a fancy and expensive housing, underwater with you unless you’re very cavalier or very insured, as my little old faithful G11 has now probably closed its little lens for the last time. But so it goes. If it could think, I hope it would have enjoyed the quality of light down there under the concrete and coral, and the sleep of electronic death. I hope it dreams of nurse sharks and giant groupers, mantis shrimp and harlequin shrimp and hundreds of nudibranchs. I hope it remembers Nepal and India, Little Cayman, Costa Rica, New Hampshire, and California. And I hope it remembers Australia fondly, less in listicles of violent and painful deaths and more in images of red dirt and teal water.

 

Goodnight from a sleepy Agent Red Squirrel- we’ll be on the boat at 7 am tomorrow, dodging the migrating humpbacks and searching for some more Sousa, as we do. From the boat, I’ll salute my new pier friends below the waves and try not to yawn too much before morning tea.