Anyone keeping Bumble Bee Shrimp?

[HiFidelity]

Hi, I just added Bumble Bee shrimp for the first time. I purchased them as an alternative to harlequin shrimp to eliminate Asterina stars because of their size and because I read that they'd leave my big serpent star alone.

Problem; serpent star lost all his legs this week, I assumed that the shrimp were eating him but now it's looking like it's more stress related than actual chomping. I left a couple of the amputated legs on the sand bed in DT and moved the star to the sump, after a couple of days the Bumble Bee shrimp have not even looked at those legs and they still lay there now untouched.

Now I'm confused about why my starfish is stressed, he's been doing absolutely great until now, what's new? like I mentioned above I've added the bumble bee shrimp, also a few emerald crabs and some snails, nothing else has changed in my tank.

Any help/opinions/advise is dearly appreciated

 

[Bongo Shrimp]

Bumble bee shrimp are less likely to eat a serpents star but they also do not require a 100% starfish diet to live. They will accept different frozen foods in addition to starfish. It sounds more like the starfish may have been starving or there was a parameter swing that it could not handle. Although serpent stars are pretty hardy, they can be very susceptible to stress from salinity and temp changes. If the shrimp, bumblebee or harlequin, were to eat a larger starfish, they will typically sit on top of the starfish and slowly eat the legs one at a time and then finally the main disk. Harlequins will actually drag the star to wherever they want to eat. For those reasons, I do not think the bumblebee shrimp played a factor in the issues you are seeing with the serpent star.

 

[HiFidelity]

I haven't tested all my parameters but salinity is a solid 1.025 for months now, PH locked in at 8.2-8.4 night to day fluctuations included in that range. and temp is also 76-77 via 2 separate heaters.

I will need to measure my other parameters to make sure nitrates or phosphates haven't gone up for any reason.

Food, I've watched this star collect food while I feed just last week.

I have absolutely no observable reason why he would be stressed and he's been in this tank for over a year now with no problems until now.

can emerald crabs attack serpent stars?

 

[Bongo Shrimp]

Emerald crabs are scavengers but eat a lot of algae. They might try to eat the dead or weak and dying star but I don't even think they would do that. Just because the star has been grabbing food does not mean it is eating. I have seen them grab food and take it to their hiding place only to decide to drop it. And again there are other parameters that can cause problems with starfish.