World?s Smallest Vertebrate?

[BallAquatics]

Measuring an incredible 7.7mm, this tiny frog from a New Guinea rainforest, sits on a US dime. Credit: Rittmeyer et al/ PLoS One

Complete article here...  http://www.reef2rainforest.com/2012/11/09/worlds-smallest-vertebrate/

Dennis

[BillT]

I like small critters.
In particular small cyprinids: Danionella (which I have) and Paedocypris (which I want to get).

I also like things you can see inside of. There is another very small frog with clear belly skin so that you can clearly see its intestines and other body cavity organs.

I had some Danionella translucida in a lab many years ago. Using a good research microscope was able to see the cells of the liver, the nuclei of eggs in females, and axons of motor neurons going from the spinal cord to the tail muscles.

Here is a picture I cropped way down to preserve resolution att he expense of showing more of the fish.
Top to bottom:
vertebrae with overlying muscles
the shapes curving down from left to right are the ribs between the body wall muscles
the red is a major blood vessel (fish equivalent of the descending aorta)
the irregular dark band is the top of the body cavity
the black spots and irregular shapes are individual pigment cells
to the right is a bit of the from lobe of the swim bladder
under the area with roundish black pigment cells are much large blobs; these are egg cells. In a few of these you may be able to squint at them and see a different looking area in the middle third. That would be the nucleus of the egg cell.
This picture was scanned from a film slide (taken in the 90's), so some of the details and resolution were lost in that process.

[Mir]

Awww cute. At first I misread the title and I thought it said "world's smartest invertebrate" and I was totally gonna say mystery snail. lol.

[LizStreithorst]

I like small critters.
In particular small cyprinids: Danionella (which I have) and Paedocypris (which I want to get).

I also like things you can see inside of. There is another very small frog with clear belly skin so that you can clearly see its intestines and other body cavity organs.

I had some Danionella translucida in a lab many years ago. Using a good research microscope was able to see the cells of the liver, the nuclei of eggs in females, and axons of motor neurons going from the spinal cord to the tail muscles.

Here is a picture I cropped way down to preserve resolution att he expense of showing more of the fish.
Top to bottom:
vertebrae with overlying muscles
the shapes curving down from left to right are the ribs between the body wall muscles
the red is a major blood vessel (fish equivalent of the descending aorta)
the irregular dark band is the top of the body cavity
the black spots and irregular shapes are individual pigment cells
to the right is a bit of the from lobe of the swim bladder
under the area with roundish black pigment cells are much large blobs; these are egg cells. In a few of these you may be able to squint at them and see a different looking area in the middle third. That would be the nucleus of the egg cell.
This picture was scanned from a film slide (taken in the 90's), so some of the details and resolution were lost in that process.

Wow, I sure wish I could see this picture in full resoulution.  What a wonderful job you have.

[BillT]

correction:

to the right is a bit of the from lobe of the swim bladder

its on the left

What a wonderful job you have.

had, don't do that anymore

Here is an attempt to use photobucket and get a bigger version of the picture:

[BillT]

Well that didn't work, try again:


or:
http://s1322.beta.photobucket.com/user/BillTre/media/Danionellaguts2.jpg.html?sort=3&o=0

[BillT]

on more time:
[/img]

or:

[LizStreithorst]

You had a great job.  Thanks for the other pic.  I can see it now.

All these X's and Y's at t's and the occasional K and f are nothing but pigment?  How interesting that if it's just pigment I turn into symbols. 

[BillT]

All these X's and Y's at t's and the occasional K and f are nothing but pigment?

Yes. Some pigment cells have lots of branches some are dots. Get a lot together and its all black (or whatever color the pigment is.

Some animals can move the pigment granules inside a cell that give it color to make that kind of cell look larger or smaller. They are often innervated, under neural control, and can change quickly. Sometimes it can be hormonally controlled and slower.

[Jo]

Love this little guy. I was sitting outside smoking and a fly landed close by and I thought wow that is the size that little frog is! 

[BillT]

The ability of evolution to miniaturize things is amazing.

I used to work with fruit flies (Drosophila melanogaster). They are about 2 mm long and are pretty sophisticated in that they fly, can see and intelligently navigate through their environment, finding widely separated food sources and mates. An impressive amount of information processing in such a small thing.

They don't have lungs. Instead they have fine little tubes (trachea) that connect to the outside at little holes on their sides and conduct O₂ in and CO₂ out of their tissues.

Some fly labs are plagued by infestations of little mites that live in these breathing tubes. There are really tiny.