Well the bad news is that the Harlequin Shrimp (just the one of them) has today killed my Sand Sifting Starfish. :cry:
I've had that Starfish for about a year now.
Took a risk and learned my lesson! Harlequin shrimp really really are not compatible with any starfish, even big ones. :embarrassed:
The Harlequin shrimp are eating the Asterinas regularly, but today for some reason, maybe as the SSSF resurfaced to relocate elsewhere, the Harley jumped on it and quickly killed it.
I thought they'd just have a nibble, but it turns out, they use their blade-like edges of their arms to quickly kill the starfish to immobilise it, so it can eat it without the starfish submerging or wondering off.
My mrs noticed the Harley shrimp was on the Sand sifter, and had only been for a couple of minutes, and she got the long tongues and lifted the starfish out into the sump, when I got back 10 minutes later, I had a look and it was already limp feeling, and had a deep gash in it's central disc.
I put it on it's back in the sump to see if it's still alive (as starfish always right themselves when upside down), it turned the ends of it's arms up a little, but very slowly, then dead.