Two More Pics I Need Identified

[got4boyz]

Since y'all were so helpful in identifying what stung me, I have two more pics from the dive that I can't identify. One I know if a type of jellyfish and the other a fish of course. LOL

I had never seen this type of jellyfish before. It was a long rectangular shape with rounded corners and it moved by folding it's body in half, then open, then back in half through the water. It was very cool! Does anyone know the type of jellyfish or are there just too many to even try to identify it?

The fish I found interesting because of the fleshy looking fin on top and it's markings. He wouldn't come out of hiding for me to get a good picture though. (Can't say I blame him. )

 

[crispos]

The blue guy is a Sargassum Triggerfish, you can see his Trigger is up to warn you off.

http://www.reef.org/member/forum/fom/nov01.htm

That Jellyfish, I will check the species, hard to see.

 

[archman]

Looks like a Mnemiopsis-type comb jelly to me. They don't sting.

 

[Phazeshyft]

that second one looks like one of those guys from "The Abyss", without the luminescence.

 

[got4boyz]

Thanks again for your help y'all.

The blue guy is a Sargassum Triggerfish, you can see his Trigger is up to warn you off.

Is that why they call them triggerfish? In the picture in the link you posted, it shows the Sargassum without the trigger up but they show the Black Durgon with the trigger up. So it can be up or down? How would having the trigger up warn something off? Or are you just joshing me? LOL

Looks like a Mnemiopsis-type comb jelly to me. They don't sting.

I looked up this on the internet and found these pictures.
http://www.imagequest3d.com/catalogue/ctenophores/

It didn't have that pear shape at all. It was pretty much square or rectangular. The best way I can describe it would be that it's shape was two squares attached in the middle (kind of like if it was hinged) and it moved by moving those two squares up and down at the middle "hinged" section. I guess kind of like a bird flapping it's wings.

I couldn't find any jellyfish in all those pictures that looked like this one.

 

[archman]

If ya' don't like it being a comb jelly, how about a sexier box jelly? They sting like the dickens, and have eyeballs.
http://www.ucmp.berkeley.edu/cnidaria/test.html

 

[got4boyz]

I finally got around to reading that site you gave me and it answered my question. This could become a new hobby, learning about all the little fishies.

"The name triggerfish comes from the fact that they can erect their front dorsal spine and lock it in place with a second spine, which is just over half as long as the first. Only after the second spine (the trigger) has been depressed, can the first spine be lowered. These clever fish use this mechanism to lodge themselves into cracks and crevices so that predators can not extract them from their positions. Triggerfishes like to eat crabs, octopus, shellfish, sea urchins, corals, and the occasional finger."

I'll be sure and keep my finger away! LOL

 

[mbuff]

I can't really make out a lot of detail in your picture, but the description has me wondering if its a pteropod -- this is a pelagic sea slug that moves with the flapping motion you described. They're a type of gelatinous mollusc. they would fit the decription of rectangular with rounded corners (tho' that description would fit a lobate ctenophore also... did you notice any comb plate rows? those lines of irridescence you see in comb jellys?... )

I also didn't get the size of the critter... how big? I think most pteropods are small.

Here's a decent place to start looking at the molluscs:
http://jellieszone.com/molluscs.htm
It is, however, west coast centric...

let us know what you figure out!

 

[got4boyz]

If ya' don't like it being a comb jelly, how about a sexier box jelly? They sting like the dickens, and have eyeballs.

LOL Archman, well if it is a comb jelly I certainly don't mind. I just questioned whether it really was or not since the shape didn't seem to match.

The box jellies appear to have tentacles which this didn't.

I also didn't get the size of the critter... how big? I think most pteropods are small.

Here's a decent place to start looking at the molluscs:
http://jellieszone.com/molluscs.htm
It is, however, west coast centric...

let us know what you figure out!

I enjoyed the website mbuff. Very good info there. Had no idea there were gelinatous molluscs. The description of how they swim sounds right, but I've looked through lots of pictures and nothing matches.

It looked to be about 2 inches, so undoubtedly smaller than that when you consider the extra magnification you have with a mask on.

I thought the black circles on it would make it easier to identify, but I've found nothing that has black dots like that.

I showed it to a guy I was diving with who had dived in Cozumel for 20 years and he had never seen one before.

I imagine there are so many different types of a species that would make it extremely difficult to identify it without better info from me. I thought I had taken a 15 sec. movie of it swimming with my digital camera, but I couldn't find it. That might have helped.

Oh well, I appreciate everyones suggestions. Maybe I'll be lucky and see another one someday and be able to get better pictures.

 

[archman]

I thought the black circles on it would make it easier to identify, but I've found nothing that has black dots like that.

Mnemiopsis and its friends very commonly have those black spots on their bodies... that's what I noticed first. I can't believe a dive guide from Coumel can't ever have seen these things. You bloody well can't avoid the things in open water.

Pteropods (which are now called thecosomatans or is it gymnosomatans?) have a shell, which would be distinctive. They do swim with a flapping motion, which comb jellies do NOT do.