Day 49

OSTRACODS

So first of all, I'd like to talk about one of the coolest things I've done in my life: ostracod dives!  Ostracods are tiny crustaceans (like crabs and lobsters) that live in the benthos (the sand, basically) and about once a month they mate.  Their mating process is like nothing you've ever seen.

An ostracod, courtesy of Wikipedia.

During mating, the males zip around in a spiral-shaped pattern while emitting pulses of light that attract the females.  How the females find the males once they stop glowing is beyond me, but there's a ton of them, so I guess it works!  Ostracods are an ancient creature and are found all over the world, but only the ones in the Caribbean exhibit bioluminescent mating signals.

Ostracods are bivalves, and live inside little shells.  They're generally too tiny to see without a microscope, although there are a few species that grow up to 2.5cm long.

This is a whole, intact ostracod.
Image from the Natural History Museum of London.

That's a pretty tiny thing!  These two specimens are each about 1000 micrometers long, which is the same as 1 millimeter.  You can't really see them in real life, but on the inside (and under a good microscope) they look like this:

Image by Dietmar Keyser.  Also, ewwwww.

Ostracod dives are a unique experience.  Lots of people think you need to time it perfectly, but the truth is, it's not that hard to get it right.  I went last night with four friends on the third day of their monthly mating, and it was incredible.  Ostracod dives are like being in outer space, if you could reach out and touch the stars.  Everyone gets their buoyancy right and then turns off their lights--so it's completely dark!  About an hour after sunset, the ostracods start their mating process, and everyone floats around in a magical, weightless state of awe for 30-40 minutes.  There's nothing going through your head except something to the effect of one very long "whoaaaaaaaaaaa."  It's like meditation if meditation were exciting.

Unfortunately, you can't really photograph this experience.  The ostracods are tiny and so the light they emit is very small.  Fortunately, some smart people at the University of Wisconsin La Crosse have taken some wonderful (and very short) videos to help us understand.

This video shows the male ostracods zipping around.  Because it's light in the room, you can't see them lighting up just yet.  (That's the next video.)  Watch how they swim quickly in a spiral:

Seriously, watch the videos.  They're less than a minute together.  Do it.  This next video is taken in the dark, and shows a single male ostracod emitting his pulsating light signals for the females.

Now imagine that times roughly 100,000.  It's like floating in a starry night sky.  There is nothing like it in the world, and I could go ostracod diving every night and never get bored by it.  I strongly recommend trying it the next time you're in the Caribbean, even if you just go snorkeling

I know you're just here for the photos, but I could keep boring you with crustaceans all day long--so I think I will!


PHOTOGRAPHS

On my days off, I like to go on photo dives.  My camera has a plastic-bag style housing, which means that I can only take it to about 20 feet before it gets wet inside.  Fortunately, there's tons of cool stuff in just a few feet of water!

Lately I've been paying extra special attention to the small stuff.  It's easy to only look at the big things and forget that the tiny things even exist.  But truthfully, the itty-bitty stuff is the coolest.  Having a camera is an added bonus because it lets me see things that I couldn't in real life.  For example, some of my shots have creatures in them that I never noticed were there until I saw the photo!

Today I have mostly two types of photos for you: shrimp photos and crab photos.  I really, really like crustaceans.  Actually, the whole arthropod phylum.  (Remember all those spider pictures?  Also arthropods.)  Do most people have a favorite phylum?  They should.

First up is a lucky find: a large Spotted Cleaner Shrimp!  He was living alone in this anemone.  Most of the photos that follow are a wide shot followed by a close-up (a crop of the same photo) to see the detail.  Shrimps are really neat!

Check out the eye stalks!

Closer....

Really close!  Look at the detail on the legs and the face.  You can see the eyes again.

Does the tail remind you a little bit of a whale?

I think their little eyes are silly-looking.

After spending some time with the spotted cleaner shrimp, I moved on to find some other shrimps.  I'd taken photos of them the day before and wanted to try again with a different camera setting.  Unfortunately the photos of those shrimps didn't turn out great, but there was lots of other stuff living in their little hole!

I'm trying to get a shot of the little shrimp.  I never noticed the big one until I saw the photos!

This is a squat anemone shrimp.  The white spots at the front are his eyes.

This is a hidden cleaner shrimp.  (That's probably why I couldn't see him.)

Same hidden cleaner shrimp.

  

He's transparent!

This crab is superb.  I saw him moving his little arms, but I couldn't see how incredible he was until I looked at the photos!  And do you notice three types of shrimps in the background?  There's a shrimp on his left (golden coral shrimp), his right (hidden cleaner shrimp), and below him (squat anemone shrimp, hard to see).

Check out the little fans he's using.  His big claws are sitting on the rock (he's upside-down) and he's using little arms with fans to bring the food closer to him.

Nice fan detail!

Flipped over and close up.

Here's another shot in which the crab is not in focus--he's that blurry bit at the front--but you can see the golden coral shrimp on the top left, a few squat anemone shrimps on an anemone, and a hidden cleaner shrimp hiding in the dark right side.

Golden coral shrimp.  You can see the bands of his arms and his arm hairs very clearly.

Here you can see the claws of the crab much better.

In this close-up photo of the crab, you'll notice that he's covered in algae.  Pretty neat camouflage!

I am in love with this crab.

More spotted cleaner shrimp photos:

Closer...

Closest!

This is my favorite photo of the day:

And the close-up of the shrimp.  If you look close, you can see hair-like structures on his mouth parts.

As I was taking photos, I felt something on my hand...

Look how tiny it is!

This guy is a type of cleaner fish.  They sit around on coral heads until a bigger fish comes to their "cleaning station."  They're a lot like the cleaner shrimps, and they eat the dead skin and parasites off the other fish.  Everybody wins!

Little fish!

This guy is less than an inch long, maybe 1.5cm.

He popped back onto my hand a few times, apparently to munch on my yummy dead skin.  It doesn't hurt when the fish and shrimp clean your skin--it actually feels like a tiny, tiny fingernail is scratching an itch!

Unfortunately my hand hair is more in-focus than the fish, but you can still make out his size and even see his little heart through his transparent skin!  He's a really little guy.

Back to crabs and shrimp!  I spent almost two hours in the water taking photos of about 5 things, haha!

Golden coral shrimp.  His face looks a little... gumpy.

From far away.  You can also see the crab (out of focus), a squat anemone shrimp's butt, and a hidden cleaner shrimp.

The golden coral shrimp came out of hiding a little bit.

Now we can see his tail!

Same players, but you can't see the hidden cleaner shrimp anymore.

Good shot of Mr. Golden Coral Shrimp's arm hairs.

Have I mentioned yet how much I adore this crab?

He was upside down in real life, but he looks cool flipped too.  His little fans are so neat!

This squat anemone shrimp shot is my second favorite of the day:

Close up.  If you look at his head (on the left) you can see his eyes, the little orange balls in white on either side of the head.

More squat anemone shrimp.

I really like squat anemone shrimp.  They are constantly waving their butts back and forth, which is pretty cute to watch.

Craaaaab!

I'll try to get more variety next time.  But tell me this isn't the neatest crab you ever saw.

This is a banded coral shrimp!  It's a small one.

Banded coral shrimp.

Golden coral shrimp!  Shrimps like to sit upside-down.

I flipped this photo.  Shrimp faces are a little freaky!

Here's a yellowline arrow crab!

These guys are everywhere.

Close up of his face.  See how yellow he is?  But his claws are blue.

That's a spotted moray eel's tail behind him.

Next to the arrow crab was a Pederson cleaning shrimp!

Those white spots on the top and bottom of the head are eyes.

He's pretty transparent.

They have lots of nice purple spots.

Eye close-up.

His face is hard to see here, but his arms and claws are clear.

Here's something lovely: two baby spotted drums!  The adults are gorgeous but the babies are downright magical.

Those long fins just flutter in the current like mermaid hair.

Close up.  Look how pretty it is!

These guys are tiny.  Their bodies and fins are only about three inches long!

Pretty!!!

The fin is folded on that right fish, I didn't cut off the tail or anything.

See?  It's folded.

I found another big fireworm:

Weird location.

Ooooh look at those bristles!

Not the clearest photo, but you can make out the details.  So complex!

I also saw a big barracuda, just chilling in like 5 feet of water.

And last but not least, here's a baby French angelfish:

Look at the blue fins.

He's a cutie!

One more shot.

The different angelfish juveniles look similar, but French angelfish babies have yellow all around their tails, like this one.

And that's all the photos for this week!  I love taking photos of the tiny things that live in the shallow water.  I hope I can afford a proper DSLR housing someday in the future, but for now, I'm pretty happy with the shots my little point-and-shoot takes.  More to come, I hope!  :)

Cheers,
Ashton