Murena is a finnish metal band formed in the year of 2000. However the band had played together few years before that with different names before Murena became stabled name for the band.
Though murena -word is close in finnish and english with one of the fishlike eel species, it has nothing to do with this. For the band the name is just enough masculine and rough sounding name to the music they play.

Read more about Murena on Last.fm.