Feeding Piscine mysis special graded small size mysis shrimp to my 180 gallon reef. I used to feed them just the regular Piscine mysis shrimp. What I found out is that while the larger fish enjoy them, some of the smaller tankmates or fish with smaller mouth like butterfly, mandarin, have trouble swallowing them whole. So I switched to the special graded small size (in pink package vs. the regular blue package). And now everyone in the tank can enjoy them, that’s also how I got my copperbanded butterfly and mandarin dragonet to start accepting frozen mysis!