When you get your new fish, many of them will not necessarily eat right away. It's best to not to feed them for 24 hours as they are getting settled in to their new tank. Though, this really doesn't apply to the porcupine puffer... Usually these fish adjust relatively quickly and will except food from you within a few hours of being introduced to their new home. I find that when many of the large breed puffers, especially porcupines, it's best with placing in live snails as the first feedings. This is what they no doubt ate before being captured, and helps them adjust much more quickly to accepting food from you. The puffers that we are discussing are active hunters, and an active hunting puffer in the wild tend to have more invertebrates in their diets rather than the less active breeds. But, luckily puffers will eat just about anything, and will quickly adapt to prepared foods. You will not be able to feed your puffer any sort of flake food; it might eat them, but don't expect to have a long-lived fish. This fish needs food with more substance, and without it this fish will not survive in captivity. Like stated before, puffers regularly need hard-shelled meals to wear down their ever-growing teeth. I've easily gotten small live ghost shrimp and varieties of live snails that are perfect to wear down the teeth of the puffers. This doesn't have to be a daily feeding, but plan on doing it at least twice to three times a week. Living food is not as important as the crunchy shell that is on them. You will also need to plan on feeding the puffer small mollusks, shrimp, and krill with their shells on them quite often. I find that if you are feeding live clams with their shells on, crack them with a nutcracker or pliers first so the puffer will be able to get a purchase on it. I use blocks of frozen brine shrimp as food, or Mysis shrimp, and then simply add in the extra foods like the cocktail shrimp, squid, and clams as a bonus to the puffer. Remember brine shrimp doesn’t offer that much nutrition, so, you will need to supplement their diet with better foods. This seems to work the best, and most cost effective. All these things can be found (with the exception of Brine shrimp) at your local grocery store. People food is perfectly fine for your puffer, and I have never had any problem with the cheapest brands of seafood with my puffers. There is a seafood mix that is sold in many grocery stores that is perfect for feeding, it contains, shrimp, squids, octopus and all sorts of other sea creatures that your puffer will love to have. This mix is suppose to be used for humans to make seafood salads... But, it comes in a nice sealed bag and it can be kept chilled for quite some time. I would like to add that if the food becomes spoiled, please don't give it to your puffer; they can get sick just the same as you and I from bad food. Certain puffers have taste for food all their own, I've had puffers that loved clams, and other puffers that wouldn't even try it. So, this is something you will have to discover as you get more use to your puffer. A varied diet is the key to a happy and healthy puffer. When dealing with foods like shrimp, crab, crayfish, clams, shellfish be careful when buying uncooked items. It is a common trick in the food industry is to douse shrimp in chlorine to kill surface bacteria. This can be fatal to your fish & aquarium, so be sure to wash the food before serving it to your puffer. This goes for fresh, unfrozen items as well. A important note when feeding live Clams, Mollusks: Grocery stores or fish markets will often have clams that seal themselves up, but are still very much alive. Make a container full of fresh seawater and place the clams inside. They will open and flush wastes. If not, you might run the risk of getting your puffer sick.
