Jellyfish navigation organ

bromodomain · Post by **bromodomain** » Mon Sep 05, 2011 11:40 am

Rhizostoma pulmo (large common jellyfish) ephyra fixed in 4% formaldehyde and included in Canada balsam. The image shows the statocyst which is a gravity based navigation organ. A population of sensory neurons make contact with the mineralized mass composed of CaSO4 and CaCO3 (seen as a multicoloured patchwork) via cilia. These mineral deposits (statolith) serve as tools to track changes in orientation and acceleration since the sensory neurons are connected to muscle cells spread around the body.

Polarisation, polystyrene compensator, 10x

ChrisLilley · Post by **ChrisLilley** » Mon Sep 05, 2011 12:41 pm

A nice image and a fascinating write-up. Thanks, I learned something new about our wonderful world today.

bromodomain · Post by **bromodomain** » Mon Sep 05, 2011 1:16 pm

Thank you Chris!

I forgot to mention that I have counterstained the ephyra with dilute fuchsin solution.

Marek Mis · Post by **Marek Mis** » Mon Sep 05, 2011 11:06 pm

bromodomain,

Nice picture. It reminds me the painting of the vase or the flowerpot with the flowers

Marek

Franz Neidl · Post by **Franz Neidl** » Wed Sep 07, 2011 1:34 pm

Hello Bromodomain,

maybe a stupid question: Why did you stain the statocyst? Is'nt it easier to see him in "normal" microscopy without staining it? Or is there an other reason?

Franz

bromodomain · Post by **bromodomain** » Wed Sep 07, 2011 6:10 pm

Hello Franz

I understand your question and the answer is that I wanted to have a permanent slide showing a nicely stained ephyra. I caught my baby jellyfish back in 2005 while on a holiday at the Black sea and fuchsin was readily available at the drug store which is why I used it. Unfortunately the organic solvent in the Canada balsam extracted most of the fuchsin and the only structure that was worth looking at was the statocyst. I knew for a long time that it was birefringent (the statolith that is) but I only recently discovered that a petri dish lid makes a somewhat decent compensator. I thought it looked interesting with the different particles showing a different colour and thats how the statocyst found its way in here

Too bad I don't have DIC but if someone has the chance to photograph an ephyra using DIC he/she is more than welcome to post it here.