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
Pint British Virgin Islands also requires that beer and cider be sold in pints. Also, in Canada, water amounts in air purifiers are advertised in pints as well as BTUs ("British thermal units"), see metrication. In Australia and New Zealand, a subtle change was made to 1 pint milk bottles during the conversion from imperial to metric in the 1970s. The height and diameter of the milk bottle remained unchanged, so that existing equipment for handling and storing the bottles was unaffected, but the shape was adjusted to increase the capacity from 568 ml to 600 ml – a conveniently rounded