Fire eels (Mastacembelus erythrotaenia) can grow to 40 inches so adult fish will need a tank of at least 120 US gallons (5x2x2'). They are predatory by nature so meaty foods like mussels, shrimp, cockles and fish should be fed, however as with all spiney eels they can be extreemly fussy so it is often just a case of getting them to eat what ever you can. Tankmates should be over 3" and tall bodied or they may be eaten.