Petroscirtes xestus Jordan & Seale, 1906

Xestus Sabretooth Blenny

Outhouse Beach, Apra Harbor, Guam. 31 Jan 2007.
Just like the reference states...a sandy area, using an empty shell as a nesting site. The shell here is mostly covered by sand, really can't distinguish it.

scubaosteichthyesactinopterygiiperciformespetroscirtespetroscirtes xestusblenniidaeblennyfish