abolutely what size tank. also I think number 1 and 2 eels really need a species only tank because they get real aggressive if I remember right. not sure what the last one is though.
some info
1)Yellow Head Eel, Gymnothorax rueppelliae, is one of the more colorful Eels available to the marine hobbyist. Also known as the Banded Moray, its brown and black barred body is accented by the golden "halo" atop its head. At a maximum length in the wild of less than three feet, it does not grow as large as some other eels, adding to its popularity for the home aquarium. Largely a nocturnal feeder, the Yellow Head Moray Eel will often be visible during the day, even if only when peering out from under or between any decorative rock provided. The Yellow Head Eel can be found in many parts of the Pacific Ocean, ranging from the Red Sea, down to the Great Barrier Reef region, and over to the Hawaiian Islands. Eels are hearty eaters who also produce a great deal of waste. Because of this, a well-established aquarium and excellent water filtration is highly recommended. This species may even learn to eat from the owner's hands (but be careful of the strong jaws.) The Yellow Head Eel is a carnivore who prefers meaty foods including silversides, krill, clam, and carnivore preparations. It may be kept with other fish, as long as the fish do not fit into the Eel's mouth. The Yellow Head Eel will likely devour any crustaceans with which it is kept. As with all Eels, an aquarium with a tight-fitting cover must be provided to prevent escape.
2)Tesselata Eel, Gymnothorax favagineus, is one of the largest members of the Eel family. Also known as the Lace Moray, its nearly-white, cream color body has dark brown or black spots that create a honeycomb appearance over the entire body and head. Its maximum captive length is considered to be around five feet (yet over nine feet in the wild), so it should be kept in only the largest of home aquariums. Largely a nocturnal feeder, the Tesselata Eel will often be visible during the day, even if only when peering out from under or between any decorative rock provided. Eels are hearty eaters who also produce a great deal of waste. Because of this, a well-established aquarium and excellent water filtration is highly recommended. Larger Tesselata Eels are notoriously aggressive and may attack humans if provoked. Its natural home encompasses the Indo-Pacific from the Red Sea down to the Australian Coast. Larger specimens are ciguatoxic as they secrete a toxin, making their skin poisonous to eat. This Eel is undoubtedly a carnivore who prefers meaty foods including silversides, krill, clam, and carnivore preparations. It may be kept with other aggressive fish, as long as the fish do not fit into the Eel's mouth.
3)The Black Edge Moray Eel originates from the reefs of the Western Atlantic. It is brown in color with stunning golden spots covering the entire body. The underside of the eel is also gold in color, and the tail is outlined in black, which gives it its name. Like other Moray eels, it has a very thick body and will typically hide in the rocks with its gaping mouth out in plain view.
The Black Edge Moray Eel requires a 125 gallon or larger aquarium with suitable shelter to conceal itself until it becomes acclimated. In time, it will have its head out in the open, or will lie out in full view. The aquarium must be equipped with a tight-fitting lid to discourage escape. Caution must be taken with the Black Edge Moray Eel, as it will eat just about anything that it can catch and fit into its mouth, including fish and invertebrates.
The Black Edge Moray Eel's diet consists of live feeder fish, squid, and octopus, and may eat the other fish in the aquarium.
Mike
