What is "micropogonias undulatus"

Sciaenoid \Sci*[ae]"noid\, a. [L. sci[ae]na a kind of fish (fr. Gr. ?) + -oid.] (Zo["o]l.) Of or pertaining to the Sci[ae]nid[ae], a family of carnivorous marine fishes which includes the meagre ( Sciaena umbra or Sciaena aquila), and fish of the drum and croaker families. The croaker is so called because it may make a croaking noise by use of its bladder; the Atlantic croaker ( Micropogonias undulatus, formerly Micropogon undulatus) and the squeteague are a members of the croaker family, and the kingfish is a drum.