Emerald Crabs and Serpent Stars

tk

Member
How predatory are emerald crabs and serpent stars?
On different occasions I found my emerald chowing down on one of my Astria turbos, now I'm finding empty shells. Then one morning I found my serpent with its arms wrapped around my flame angel.
Did they kill them or are they just doing their job, cleaning up the bodies?
Thanks guys,
Tom
 

fishcake

Member
I had a serpent star that devoured my chromis.
I know that when they prop themselves up on there tentacles in a bridge like fashion that they are "imho" Predatory.
If you see this behavior you should probably trade him in.
 
I don't have any serpent stars but I have several Emerald crabs and they have never killed anything that I know of. I rarely see them. They are usually in the LR. My Blue legs get my snails more than anything but even then I think it is mostly when the snail falls down and is upside down.
 

paulcoates

Member
I have seen in person a Serpent Star make quick work of an Emerald Crab. I mean, like, he was put in, hit the sand bed, then an arm came flying out from under the rocks, and that was it for the emerald
 

ophiura

Active Member
Don't jump to conclusions. It is easy to say "oh my fish was healthy and it was KILLED' when in reality, no such thing happened.
What color is the brittlestar?
How long have you had this tank?
How long did you have the angel?
What are your SPECIFIC water parameters?
IMO, it is more likely that the fish died, and it was being cleaned up. As for the emerald, it is opportunistic. And many will eat what they can find, not just algae.
FWIW, I have 10 large brittlestars in a 45g, and can't blame them for losses. Two of my losses were angelfish...and I know both died first. One was a clown goby, and he was gone within 24hours (quite possibly died first). I also lost a shrimp, that may very well have been eaten, or it might have died in a molt. The green brittlestar is a KNOWN predator, but others are not.
In most cases, IMHO, our fish die...and are not otherwise perfectly healthy.
 

ophiura

Active Member
I am well aware that this species does this. No doubt, no question...but fish also die in our tanks, and people jump to conclusions as well, because it is easier to deal with something else KILLING our fish than dealing with the fact that we may have caused its death.
There are thousands of species of brittlestars, and dozens in the hobby, and they do not ALL do this.
This animal is accused of killing, IMO, outrageous things - triggerfish, tangs...things that are significantly larger. And that I do not buy. Gobies? Small stuff? sure...not always, but some individuals will.
Also remember, the brittlestars have slits on the underside of their disk. It is where they breathe, and so they often are not sitting on the sand but somewhat arched up.
IMO, jumping to the conclusion may overlook a clear problem.
 

fishcake

Member
Tk,
If your star is not a green one, I would have to agree that it probably died before your star got it.
 

ophiura

Active Member
Originally Posted by Fishcake
I only Know that mine was a predator because I caught it in the act of catching the live fish.

Unfortunately normal. It is too bad that this is such a colorful and relatively hardy species, because it just isn't a good one. It isn't much, but at least you KNEW what killed the fish. It is the unknown that makes you go crazy.
But they certainly ARE capable of this behavior. I wouldn't rule it out for sure. But it would be hard to know unless, like you, they see it directly. I love watching my tank
but not that much.
 

reefkprz

Active Member
Originally Posted by ophiura
But they certainly ARE capable of this behavior. I wouldn't rule it out for sure. But it would be hard to know unless, like you, they see it directly. I love watching my tank
but not that much.

my tank has been my saviour I've been laid up almost three weeks now, I've been watching my tank WAYYYYY more than that much. thankfully its next to my bed.
 

hatessushi

Active Member
Originally Posted by Fishcake
Just to be clear on the star in question....I have attached a pic of mine propped up in position.
hmm, doesn't look like it's doing anything there. What's he suppose to be doing there?
 

tk

Member
Originally Posted by snookedsteve
I don't have any serpent stars but I have several Emerald crabs and they have never killed anything that I know of. I rarely see them. They are usually in the LR. My Blue legs get my snails more than anything but even then I think it is mostly when the snail falls down and is upside down.
I think you are right. I have two Emeralds that pretty much stay to themselves. I enjoy watching them pick through the rock. I caught one of them with his pincher buried up to the elbow, in a turbo, butI'm not going to convict himof killing it. Thanks for the post, Tom K
 

tk

Member
Originally Posted by paulcoates
I have seen in person a Serpent Star make quick work of an Emerald Crab. I mean, like, he was put in, hit the sand bed, then an arm came flying out from under the rocks, and that was it for the emerald
I guess that's life in the ocean, huh. I think that probably everything will eat everything else, given the right circumstances. Thanks, Tom K
 

tk

Member
Originally Posted by ophiura
Don't jump to conclusions. It is easy to say "oh my fish was healthy and it was KILLED' when in reality, no such thing happened.
What color is the brittlestar?
How long have you had this tank?
How long did you have the angel?
What are your SPECIFIC water parameters?
IMO, it is more likely that the fish died, and it was being cleaned up. As for the emerald, it is opportunistic. And many will eat what they can find, not just algae.
FWIW, I have 10 large brittlestars in a 45g, and can't blame them for losses. Two of my losses were angelfish...and I know both died first. One was a clown goby, and he was gone within 24hours (quite possibly died first). I also lost a shrimp, that may very well have been eaten, or it might have died in a molt. The green brittlestar is a KNOWN predator, but others are not.
In most cases, IMHO, our fish die...and are not otherwise perfectly healthy.
Thanks, you're probably right. The angel could have, very well, croaked on its own and the serpent was just doing its job. Any evidence to the contrary is purly circumstantial. I just hate to see a $40 fish eaten. :notsure:
Thanks for the post, Tom K.
 
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