I have yet to see even the smallest clown goby refuse live brine shrimp. I use live brine shrimp to make sure all my newlky acquired gobies and other small fish eat. May not be the most nutritious food, but they are not gonna starve. Often times it takes a movement to stimulate a fish to grab ahold of food. Once its eating BS then add in some other foods like frozen foods. Overall those little fellas do not eat a lot of food, and from my observations if they are started off with a food source that is not appealing to them or is too large for them to break off and eat, they loose interest pretty quick and just go find a coral or rock to perch on and watch the world go by while other fish consume the food. Try feeding even frozen brine shrimp and do not turn off the powerheads so it looks like it is alive from water flow. You can hatch out a batch of live brine shrimp by this time tomorrow if you have eggs. I keep a supply of bs eggs on hand all the time as they have saved me well actually a fish from time to time and they are dirt cheap to buy.