Human grade seafood is best, as any seafood sold for the pet trade is treated with Ethoxyquin unless specifically stated, that's why "not for human consumption". This preservative is bad news and may be one of the contributing factors of the dismal captive life span in specifically predatory fish, eels included. Shrimp with shells, scallop, squid, clams and mussels. Mussels have great nutrients including a high amount of B1, which is a common deficiency which effects eels. Although the zebra is a pebble tooth, some chunks of salmon if they will take it, tremendous amount of efa's and B1. If you buy fresh and freeze in small batches that you use within a few months, you could have that eel for as long as 20 years, where most only keep them a few years. Overfeeding, usually in the form of too frequent feeding is also a leading cause of death; this creates fatty liver disease. Eels do best on a gorge fast eating schedule; feed their full, then a few days between for digestion, eventually getting into something like a weekly feeding. They also appreciate a live fiddler crab and as I mentioned, shell on shrimp, just trim any sharp edges. Shells are vital for ca and other minerals, maintaining reef levels of ca and mg, fish do use nutrients from the water column.
