External gills usually contains muscle tissue, and may be moved by the animal as a free appendage, in order to stir up stagnant water. The stalk is lined by many thinly walled filaments (fimbriae), containing the majority of blood vessels used in gas exchange. Animals usually have one external gill originating on each gill arch (except the hyoid), which leads to there being three pairs of external gills in salamanders, and four in the gilled larvae of lungfish. External gills External gills are the gills of an animal, most typically an amphibian, that are exposed to the environment, rather than set inside
How Many Words 13, 2008. Lewis performed the song live on the March 6, 2008 results show of the seventh season of "American Idol". The single has sold 94,000 copies to date. How Many Words "How Many Words" is the official second single by the singer-songwriter Blake Lewis, from his debut album "A.D.D. (Audio Day Dream)". The song was expected to be followed by "Know My Name", and then "Without You". However, due to being dropped by Arista Records, "How Many Words" is the final single from his debut album. He is expected to release a single from his second album at the