Anyone's sea urchin eaten their starfish?

[RussC]

I noticed a long time inhabitant of the tank, my red tile starfish, had two digits that looked like they were chewed on. Its been 48 hours since I took the attached pic. Those legs are just about gone. Then I noticed my red serpent star had lost two digits. Now my tile starfish digits are just about gone and the tip of another one is wounded. I've been all over the web reading about this. Nothing seems to make sense. And now I've learned a long spine sea urchin can become aggressive if hungry enough. He's about the only critter in may tank with the hardware to do what I see. Anyone else seen this happen?

 

[zachfishman]

We separate urchins and sea stars in our touch tanks because urchins do sometimes go after the stars. Specifically the species I've seen making trouble are pencil urchins (E. tribuloides) eating chocoloate chip stars.

 

[ca1ore]

Much more likely the star is dying and disintegrating.

 

[Uncle99]

Yup, stars for the most part should remain in the sea, they don't last long in the confines of the glass box, urchin probably just passing through.

That being said, if you have expensive stuff you don't want destroyed, be wary of urchins, sometimes they can be a big PITA, had one punch a hole right through a clam shell.

Just my take, many have great success apparently with them, I put them in with crabs, cannot be exclusively trusted.

 

[zachfishman]

Variegated and tuxedo urchins I trust in reefs. So far so good.

 

[Uncle99]

Variegated and tuxedo urchins I trust in reefs. So far so good.

Absolutely correct!
My thinking was a bit selfish, I sleep better at night now that all is safe.
Just never seemed to have any luck with CUC types.

I found out in the end that except for snails, other CUC members were not necessary. Just great water, 100% of the time.

But your right, urchins are quite easy to ID, crabs, not so much...

 

[top shelf]

Absolutely correct!
My thinking was a bit selfish, I sleep better at night now that all is safe.
Just never seemed to have any luck with CUC types.

I found out in the end that except for snails, other CUC members were not necessary. Just great water, 100% of the time.

But your right, urchins are quite easy to ID, crabs, not so much...

I'm with you no urchins, crabs, or shrimp. Just snails although I have been contemplating a tiger tail cucumber.

 

[Uncle99]

I'm with you no urchins, crabs, or shrimp. Just snails although I have been contemplating a tiger tail cucumber.

Thanks Topshelf, I guess you may have had similar experiences.
I'm actually ok with the cucumber, its the claws and the teeth inhabitants that worry me, And cucumbers actually do a pretty good crap clean up.

 

[top shelf]

Thanks Topshelf, I guess you may have had similar experiences.
I'm actually ok with the cucumber, its the claws and the teeth inhabitants that worry me, And cucumbers actually do a pretty good crap clean up.

Had cleaner shrimp steal and dig food out of bta and lps coral. An urchin while he did a great job at cleaning algae take anything that wasn't nailed down and eat some corals along his grazing path. Never had hermits or other crabs but know they are opportunistic and like my fish too much. With snails yea I can do more work then them but there's really no downside either. As for a cucumber my only real worry is will my tank be large enough to sustain it.

As for the OP when picking inhabitants it comes down to risk vs reward. Understanding how much good can this critter do vs how much damage can it do and make an informative decision.

The star could be dying or it could be getting eaten. You can opt to remove the urchin and if the star is truly healthy it will regrow the limbs, if not likely it is dying slowly like most will do.