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
Imperial and US customary measurement systems 277.42 cubic inches (4.546 litres). Twenty imperial fluid ounces make an imperial pint, the imperial fluid ounce being 0.96 US fluid ounces. The US Customary system of units makes use of set of dry units of capacity that have a similar set of names to those of liquid capacity, though different volumes - the dry pint having a volume of 33.6 cubic inches (550 ml) against the US fluid pint's volume of 28.875 cubic inches (473 ml) and the imperial pint of 34.68 cubic inches (568 ml). The imperial system of measure does not have an equivalent to the US