Blue color variation of Stomolophus from Puerto Pensaco, Mexico.
Kim Fleischhauer sent me this photo of a partially decomposed jellyfish she took on the beach in Puerto Penasco, Mexico for identification. I was a bit stumped at first. I immediately recognized the body structure of the jelly as that of Stomolophus, the Cannonball jellyfish (aka Cabbagehead).
But the blue coloration was confusing. I’d never seen one this color. And such a deep blue it is.
The ones I see on the beach in Florida normally look like this:
This is the way the Cannonball jellyfish normally looks when it washes up on the beach in Florida.
A bit of digging on the internet turned up the following information regarding a blue color variation in Stomolophus:
In the San Diego specimens the general color of the bell is Prussian blue, pale at the apex, deeper at the margin… The oral arms are likewise pale Prussian blue; the lips whitish. –Henry Bryant Bigelow, Note on the medusan genus Stomolophus: from Sandiego, Vol. 13, No. 10, pp. 239-241, Univ of Cal. Press., 1914
Bigelow had received several Stomolophus specimens from San Diego Bay, California and was comparing them to their Atlantic counterparts, which appear as in the photo above. Bigelow notes that the color variations are not accompanied by any structural differences.
So, it appears that the mystery is solved. It is amazing to me the range of color variation in the same jellyfish. I wonder if it is diet related?
UPDATE 7/10/2012:
I’ve just received a photo from Kelly Contreras also taken at Puerto Penasco. This is of a live blue Cannonball Jellyfish:
Kelly has also shared this video of the Blue Cannonball Jellyfish in Puerto Penasco, Mexico:
