Male eels do not get very big at all, about 15"-18" or so. They also like to hang out more in full salt or brackish water, wereas the the females get much larger, and typically live in full fresh. They breed in the sargassum sea, very close to the european eels, but do not seem to interbreed with them. They have several life stages before they metamorphise into the shape we see as eels. They are very tough, but if they do not like their surroundings will attempt to leave. I fed mine pellets, shrimp, minnows, squid, anything really. I did not see mine for almost 6 months when first introduced into the tank, but all the sudden she started coming out, and appeared to be very healthy. A tight fitting lid is an absolute must.