A look at a rare hitchhiker coral predator. Have you seen this one?

[Amphibious]

Today when doing my rounds of the aquaculture system, I noticed a coral that just didn’t seem right.



The pic above is from when I received it back in July. Nothing unusual, two healthy heads. Unfortunately, when one head died and the skeletal structure literally dissolved away, I didn’t investigate. Corals are living things subject to death. We lose them for no apparent reason sometimes. Today when looking around that system something was not right about the remaining head. It was attached to the base rock by a sliver of it’s structural stem. Not thinking of pictures at the moment I picked up the rock to take a closer look and the coral literally fell away, it broke off the rock. Upon further investigation I didn’t understand what I was seeing. Being one with my handy dandy underwater Olympus camera I took the following pictures.



This picture shows the skeletal structure severely deteriorated. I thought this was very strange.



Turning the coral a little, the above picture shows something seemingly attached to the Calcium structure of the coral.



Flipping it 180*, revealed what looked like a clam shell attached to the coral stem. I was fascinated at this point and very puzzled.



Rotating the piece another 90* revealed the familiar zig zag of a clam shell. I could scarcely believe my eyes yet the evidence was right there. I know there are burrowing clams that slowly dissolve rock as a source of calcium to build their shell but, a coral killing clam that sucks the calcium out of the structure of a coral? That was new to me. I had to know more.

Since the coral head was healthy for the moment, I decided to frag off the head and mount it to a frag plug, which I did.



In my excitement I dug out the coral’s decimated stem before taking the above picture. It was tightly attached to the clam. I had to use a pointed steel tool known as a scratch all.

Continued below...

[Mostly Rock]

Cliff hanger! Who needs movies and novels when Amphibious leaves us hanging like this!?

[Amphibious]

Ha ha, Mike, it’s coming, it’s coming. Patience Grasshopper.

[Amphibious]

It was hard for me to accept this to be a clam killing a coral. I scratched around inside the clam shell and sure enough...



There was the proof positive this was a live clam feasting on the coral’s calcium structure.



Looking down through the cleaned out shell you can clearly see the scalloped opening.



Flipped over view.



The final shot of the clam’s shell.



And the saved Neon Green Aussie Hammer, with somewhat shortened stem.

Dick

[Mostly Rock]

That's just weird...

[Amphibious]

The weirdness continues...

This morning, while checking corals more closely now, I found the other head from the coral above.



With it’s stem weakened to the point of failure to hold the weight of the coral head, it broke away and was pushed around by the current.

Here’s the thought I had, maybe the clam’s purpose in life besides it’s own survival is to CAUSE corals to spread around the reef and form new colonies. It seems logical that eating away at the base of a coral and (my original thought) destroying the colony is self defeating in that the clam would be destroying it’s source of energy, thereby reducing it ability to reproduce and carry on it’s gene pool. By not destroying the coral head but causing it to drop and be shifted around by currents it spreads the colony and thereby insuring it’s offspring an ongoing food source.

Pretty interesting stuff, this reefing in captivity!

Now, I’ll square off the stem and mount him to a frag plug.

[Amphibious]

Late this afternoon I cut off the jagged end of that coral and mounted it to a plug.



This was a fascinating find. Having gone through this process, it reminds me just how little we hobbyists really know about the hitchhikers that come in on our corals.

I have learned a lot from this lesson. I hope you did, too.

Happy reefing!

Dick

[Mostly Rock]

I certainly did. Imagining a vicious coral eating clam, then recalibrating my mindset... It's a natural fragger! This clam frags corals and propagates reefs! How many other denizens of the deep do this? I also decided that I need to go get one of those frags from you... the Neon Green Aussie Hammer is a beautiful coral!

[Amphibious]

Very astute Mike. I’m going to let these heal from their ordeal and glueing to a plug for a couple of weeks. I’ll be sure one has your name on it.