Hatsune Miku: "Fish" song

I just got this Video at Crunchyroll pulse post, and I do not know if its a new or old song but it a cool song like others said in Crunchyroll, and have a nice video, now only the thing that confuse me is that the name of the song is "Fish", well it kind na short title than the others, maybe title is really like that so .... oh well  sigh......