They need live and frozen foods. Many pet shops sell worms and shrimp, alive and frozen, for fish like puffers. Keep in mind that puffers need hard, crunchy food in their diets like snails or shellfish because their teeth never stop growing, and they need hard foods to grind down their teeth.

Can Pea Puffers be kept with shrimp?

They nip fins of bigger fish so a yummy shrimp would soon be eaten sooner or later. However I'm sure some have kept pea puffers with some success with shrimps. As discussed before the only safe fish with shrimp is the oto. Even my endlers will nip at small baby shrimps and harrass some of the juvies.

Will pea puffers kill shrimp?

From what I've been reading on the subject, reports are all over the place, from 99% of dwarf puffers will attack and kill shrimp, to "it depends on the DP's disposition" to "'I've had dwarf puffers and shrimp together for years with no problem."