[Delphinus]

I thought shrimp, at least Lysmata shrimp (cleaners, peppermints, etc.), are particularly senstive to SG. I've found just throwing them into water that's different by 0.002 (i.e. 1.023 vs. 1.025) to be disastrous. I always drip acclimate them now over 1/2 hour to an hour (depending on how different the SG's are. If they're identical SG's I'll still do the drip but maybe not as long). For stars and urchins I'd consider a really slow drip acclimation. When I acclimated my linckia, I set up a container in the sump (for temperature control), then slowly dripped into the container over 16 hours before releasing him into the tank. It seemed to work OK, but even so I noted that the star did not really move much for the first 3 weeks or so. Then he climbed to the top and circumnavigated the tank a few times (seemed like he was exploring his new environment, discover the limits/extents of the "tide pool"). It was weeks yet before he would wander the rocks. Now I find him zooming (by comparison) all over the tank. Makes me think that even with the 16 hour acclimation, it was still a hard hit for him to get over. What was the original question? I've forgotten. Oh, I see it had nothing to do with stars. Crud. I've gone off on another tangent. Sorry, my bad.