Exploding Larvae

[Henryville]

I observed something interesting while on a night dive and I am wondering if it was "natural" coral feeding. I was diving a shallow mixed reef in Grand Cayman. With my HID light on, I was attracting the usual cloud of tiny fish, shrimp, and assorted unidentified wiggly things.

I was looking at a small hard coral, maybe 4 inches across, when I noticed that the orange colored wiggly things, maybe 2 - 5 mm in length, would occasionally come close to the coral, possibly touch it but usually not that I could see, then suddenly "explode" with a small wisp of milky material left behind.

I know the light is intense, and I am hoping wasn't "vaporizing" them with it. Is this what one would expect to observe from a feeding hard coral?

Thanks

 

[Mr.X]

I observed something interesting while on a night dive and I am wondering if it was "natural" coral feeding. I was diving a shallow mixed reef in Grand Cayman. With my HID light on, I was attracting the usual cloud of tiny fish, shrimp, and assorted unidentified wiggly things.

I was looking at a small hard coral, maybe 4 inches across, when I noticed that the orange colored wiggly things, maybe 2 - 5 mm in length, would occasionally come close to the coral, possibly touch it but usually not that I could see, then suddenly "explode" with a small wisp of milky material left behind.

I know the light is intense, and I am hoping wasn't "vaporizing" them with it. Is this what one would expect to observe from a feeding hard coral?

Thanks

Were you able to collect any of the orange guys? It would be interesting to find out if it were a defensive move (excretion) on the part of the worm. The nematocysts on a coral are so fine as to be mostly invisible to the naked eye. X

p.s. could be a doctoral thesis or new pharmaceutical in the rough

 

[Henryville]

Didn't collect any, but they were definitely animate (not excretions.) I observed them throughout the dive, and they were definitely moving on their own.

I love night dives, I see more odd stuff then by far than I do on day dives.

 

[Mr.X]

Didn't collect any, but they were definitely animate (not excretions.) I observed them throughout the dive, and they were definitely moving on their own.

I love night dives, I see more odd stuff then by far than I do on day dives.

That's for sure.

There are so many wormy guys out there that without collecting one and ID'ing the critter it's hard to determine what's going on. Small field microscopes, or even lit hand lenses are great for divers who are into marine ecology. Most of the divers I know are not much into collecting the little guys. On one dive in the NE there was a bloom of caprellans. These guys stuck to everyone's drysuits. The name that everyone gave them was "aliens". Most of the caprellans got stuck to the suits and created quite a stink. A caprellan under a scope is a fascinating organsim. I am digressing. X

 

[archman]

might just be stored gametes from an epitoke... that's what it sounds like to me.

 

[skinerd]

stored what from a what? duh... For those of us from up north that don't dive the reefs, could we get an explination? Much appreciated.

 

[archman]

yeah, I guess I should have put more explanation into it.

An epitoke is a disgusting reproductive stage of certain marine worms, which Leslie would know a lot more about than I.

Either the whole worm or just its rear end transform into a free-swimming squiggly thing. This thing is chock-full of eggs or sperm... and ready to pop "white stuff" out for a nothing.

You see epitokes all over tropical reefs at night. Which is one reason I don't night dive. They're gross.

 

[skinerd]

thank you, much appreciated
Andrew