Cell division

["Umm fish?"]

Here are some new sixline wrasse embryos (embryo = more than one cell), probably about 30 minutes old.

 

[Recty]

I think your macro lens might be better than mine

Great shot!

 

[Reef Bass]

Way cool. Ok, how did you do it? The EXIF info says 65mm lens, but that had to be pointing through the ocular of a microscope or something.

 

[dendronepthya]

Could be that odd 5x macro that is listed at 65mm

 

["Umm fish?"]

Well, remember that cells in eggs are really big--at least for the first few cell divisions--since the mass (and size, too, really) of the eggs remains roughly the same at one cell all the way to at least 32 to 64 cells. I don't believe the animal can digest any of the yolk until it has enough cells to form a primitive digestion system, so it only starts growing then.

Okay, equipment and setup: It is the MP/E-65mm macro with a couple of external flashes. But the photo was only somewhere between 1x and 2x and then cropped. Easily achievable with a 1x macro and tubes.

The eggs are in a large yogurt cup (white plastic). I also have an LED light (one of those small video recorder lights) diffused through the container from below to give through-light. I needed a little more speed on the exposure because there's a little camera shake. Or a tripod. Some shake might have been inevitable because the eggs are very, very buoyant and never stop moving.

 

["Umm fish?"]

Okay, so this morning the embryos are in a couple of different stages. Most are still in the "big ball of cells" (blastosphere) stage:

You can no longer really make out the individual cells. The embryo likely has a working, primitive digestive system now, though. The yolk has started shrinking away from the egg membrane (chorion) just a little.

This other guy has made the next big leap. It's organized itself into a long, thin tube that runs around the inside of the cell membrane. It's still a pretty flat tube because there still aren't a whole lot of cells to go around.

The tube gets longer and fatter while the embryo starts working on internal structures.

 

[AquaticFins]

Neatest thread I've seen in a while!

Thanks for the photos.

 

[TitusvileSurfer]

Umm, WOW!

 

["Umm fish?"]

Thanks, y'all! These guys aren't _that_ small though, a little smaller than a millimeter.

I took some pictures of Cerith veligers the other day. _They_ are small. The first photo is the whole shot taken at 5x life size.

They make the copepod look huge. A crop.

I have to admit. I _did_ use a tripod for that one.

 

["Umm fish?"]

And we have a chordate! The end of the tail is on the upper left, near the oil globule. The head is at the other end.

 

["Umm fish?"]

And 189 more eggs tonight!

 

[Tremont]

That's amazing...

(would be incredible in time lapse...get's me thinking).

 

["Umm fish?"]

Thanks! But if you want to see it over time, here's a video of the early development:

http://www.youtube.com/watch?v=T9MeSOzU27k

 

["Umm fish?"]

Check it out! Lots of prolarvae today!

So, this is with normal processing to make it easier to see:

This is with the curves pushed way out of normal to increase the contrast:

And labelled:

And another prolarva:

They still don't have working mouths and their eyes may not work yet, but probably time to start acclimating them to the larval rearing tank. "Rearing" is an awfully hopeful word, yeah?

 

[J. Montgomery]

Very cool pictures. At one point I worked in a lab that studied early mouse development up through the blastocyst stage, really cool stuff.

 

["Umm fish?"]

Nice, Josh. How long does it take mice to get there? And, can you explain the difference between a blastocyst and blastosphere? Sorry, I don't know much about mammal development and still have a lot to learn about fish. I should have this book by Monday, though: :rollface:

http://www.springer.com/life+sci/zoology/book/978-1-4020-2996-7

(You can find it cheaper than the Springer price, I'm just linking directly to the publisher.)

 

[J. Montgomery]

IIRC, I think they're two names for the same thing. Blastocyst is the more commonly used term though. Mice embryos reach the blastocyst stage around 3-4 days post fertilization at which time implantation occurs. The inner cell mass will become the embryo, and the outer layer of cells (trophoblast) will become the placenta.

 

["Umm fish?"]

Maybe with fish it's not called the blastocyst because there's no placenta involved, so I assume that outer layer of cells isn't there? Cool stuff.

Sounds like a cool job, though I know that some lab jobs descend to the tedious.

 

[JStraz4991]

thats cool

 

["Umm fish?"]

A few more from the weekend: