Clams are eaten by starfishes ???

[DSC reef]

Agree. That clam has no visible shell growth and algae on the inside of the shell which could indicate a dying clam to begin with. While I can't stand asterinas I don't believe they kill and eat tridacna.

 

[2Sunny]

How do you know they were killing the clam vs. just eating the already dying or dead tissue? They are well known to be scavengers.

a) The clam was alive and apparently healthy just yesterday. I've had it for about 3 years, but as soon as I noticed it wasn't expanding I immediately sacrificed it because this was my second case.
b) The first time this happened to me, I found stars on the shell of the first victim, but didn't put 2 and 2 together
c) Read the ReefKeeping article. There are many species of asterina. Not all are reef safe.
d) The OP is one of many posts similar in nature both here and on RC

Is the evidence circumstantial? Yes. Can I "prove" the theory that some asterinas eat clams? No. But, tell you what I'm gonna do. I'm gonna take out my surviving clams. Buy 6 Bumble Bee shrimp. Wait 'til I don't see any stars and re-introduce my clams. Then in a few years if the clams are fine I'll have a little more proof. After 20 years of reef keeping I've learned nothing good happens fast in an aquarium and sometimes it takes years to see results.

Just for perspective here's my tank at it's zenith about 7 years ago . . .

 

[DSC reef]

Just because your clam was "alive" doesn't mean it was not in poor health. A healthy tridacna should not have algae growth on the inside of the valve and a thriving clam will always have new shell growth. Not saying you did anything wrong, just sharing my experience with growing tridacna for many years. That's a really nice tank.

 

[DSC reef]

@2Sunny your tank pic looks very similar to the one pictured in this article....

Saltwater Algae Control: The Ultimate Guide | Home Aquaria
http://homeaquaria.com/saltwater-algae-control-the-ultimate-guide/

 

[Bongo Shrimp]

a) The clam was alive and apparently healthy just yesterday. I've had it for about 3 years, but as soon as I noticed it wasn't expanding I immediately sacrificed it because this was my second case.
b) The first time this happened to me, I found stars on the shell of the first victim, but didn't put 2 and 2 together
c) Read the ReefKeeping article. There are many species of asterina. Not all are reef safe.
d) The OP is one of many posts similar in nature both here and on RC

Is the evidence circumstantial? Yes. Can I "prove" the theory that some asterinas eat clams? No. But, tell you what I'm gonna do. I'm gonna take out my surviving clams. Buy 6 Bumble Bee shrimp. Wait 'til I don't see any stars and re-introduce my clams. Then in a few years if the clams are fine I'll have a little more proof. After 20 years of reef keeping I've learned nothing good happens fast in an aquarium and sometimes it takes years to see results.

Just for perspective here's my tank at it's zenith about 7 years ago . . .

To point A, that’s a fairly commonly seen way for tridacnids to die in aquariums. There’s debate about what causes it, but I don’t see how that can be attributed to the starfish.

To point B, if you’ve had this happen to other clams, it still could be that the starfish are scavenging the dying tissue. How does that inherently implicate them in the death of the clam?

To point C, the article doesn’t say anything about predation on clams. “Not reef safe” seems to refer to corals in that article.

To point D, it certainly makes sense that you’d find the stars in or around a dying clam, or any other dying animal in an aquarium.

I agree with DSC reef here. If that clam was the picture of health yesterday, the inside of that shell would be pearly white. Perhaps the clam was close to death, but wasn’t showing signs of a problem, again a common occurrence, and the starfish made their way in, unrelated.

 

[DSC reef]

Also @2Sunny you posted on January 18th of this year that you just had a tank crash due to neglect last winter and starting over, was that clam from the same tank?

 

[Bongo Shrimp]

That’s a pic of Joe Peck’s famous tank from 2011. If you’re gonna make this stuff up, at least put in a little effort.

https://www.advancedaquarist.com/2011/3/aquarium

 

[DSC reef]

That’s a pic of Joe Peck’s famous tank from 2011. If you’re gonna make this stuff up, at least put in a little effort.

https://www.advancedaquarist.com/2011/3/aquarium

I just noticed this member is referring himself as Joe Peck from previous posts. Could it be him or do we have an imposter...

 

[Bongo Shrimp]

I just noticed this member is referring himself as Joe Peck from previous posts. Could it be him or do we have an imposter...

Oh then idk, but I recognized the tank and hadn’t read about it in a long time.

 

[DSC reef]

Oh then idk, but I recognized the tank and hadn’t read about it in a long time.

We did too

 

[MnFish1]

Starfish eat clams..... At least some kinds of starfish eat some kinds of clams.

 

[MnFish1]

So either the clams died or were dying and the starfish scavenged them, or the species of starfish you had were predatory. Just because the ones you had ate or appeared to eat live clams, does not mean they ate the clams alive as predators, nor does it mean that most starfish eat live clams.

Right - but it doesnt mean the opposite either. Google it... Certain starfish eat clams. How does ANYONE know besides conjecture what happened in this tank to this clam with these stars?

 

[DSC reef]

Right - but it doesnt mean the opposite either. Google it... Certain starfish eat clams. How does ANYONE know besides conjecture what happened in this tank to this clam with these stars?

That's why there are both sides represented. I've never seen asterinas eat a healthy clam but it doesn't mean it has not happened. There is no denying that that clam was already in very poor health which, IMO, refutes a claim that the asterina found is what killed a "healthy" clam.

 

[Bongo Shrimp]

That's why there are both sides represented. I've never seen asterinas eat a healthy clam but it doesn't mean it has not happened. There is no denying that that clam was already in very poor health which, IMO, refutes a claim that the asterina found is what killed a "healthy" clam.

I was literally typing the same thing. And just because one species eats mollusks, doesn’t mean another does. It seems like there’s a lot of evidence showing asterinas as scavengers and some decent evidence leaning towards possible coral predation, but there doesn’t seem to be any that really shows or suggests that they will kill large mollusks.

 

[Bongo Shrimp]

IMO, with the current available information, this is an example of Occam’s Razor where the simplest explanation would be that the scavengers are scavenging. That’s where my position comes from.

 

[MnFish1]

I was literally typing the same thing. And just because one species eats mollusks, doesn’t mean another does. It seems like there’s a lot of evidence showing asterinas as scavengers and some decent evidence leaning towards possible coral predation, but there doesn’t seem to be any that really shows or suggests that they will kill large mollusks.

Thats what I said - some do some dont.... I dont think Asterina stars eat clams.... Are were sure these were asterina stars? or a type of star that looks like asterina stars. The pictures seem more 'even' than asterina. But I have to say - im not sure whether those are hitchhikers or asterina - or something else

 

[Bongo Shrimp]

Thats what I said - some do some dont.... I dont think Asterina stars eat clams.... Are were sure these were asterina stars? or a type of star that looks like asterina stars. The pictures seem more 'even' than asterina. But I have to say - im not sure whether those are hitchhikers or asterina - or something else

Oh, it seemed like you were using one to prove the other.

I think debating what type of starfish they are is a different discussion. Whatever they are, there doesn’t seem to be enough evidence to conclude that they killed the clam. The condition of the shell being key in that opinion.

 

[zoous]

You don't what kind of asterina stars those are in the pic. So it's very possible not all asterina stars are reef safe. Your just making an assumption based on what your experience or what you heard or read. In my experience some are reef safe but there are some that aren't safe at all.

 

[Bongo Shrimp]

You don't what kind of asterina stars those are in the pic. So it's very possible not all asterina stars are reef safe. Your just making an assumption based on what your experience or what you heard or read. In my experience some are reef safe but there are some that aren't safe at all.

Is there a species of asterina starfish that is a known mollusk predator?

 

[MnFish1]

Oh, it seemed like you were using one to prove the other.

I think debating what type of starfish they are is a different discussion. Whatever they are, there doesn’t seem to be enough evidence to conclude that they killed the clam. The condition of the shell being key in that opinion.

Agree. This is a constant debate right - did the things on the 'dead thing' kill it - or are just scavengers. The thing that I was interested in here is the claim that there were 'eggs' in the clam - suggesting this didnt happen quickly (perhaps).