Scales protect the fish from its environment. They overlap like shingles on a roof so that the skin of the fish is not exposed. As a fish grows, their scales produce rings much like a tree-and that is one way scientists can tell how old a fish is.Most fish get extra protection from a layer of slime that covers their scales. This slime helps them move through the water better, and keeps pests off of the fish skin.s a fish grows, their scales produce rings much like a tree-and that is one way scientists can tell how old a fish is. Most fish get extra protection from a layer of slime that covers their scales. This slime helps them move through the water better, and keeps pests off of the fish skin.
Inside a Muffler. Located inside the muffler is a set of tubes. These tubes are designed to create reflected waves that interfere with each other or cancel each other out. Take a look at the inside of this muffler: The exhaust gases and the sound waves enter through the center tube.
An exhaust manifold or headers are bolted to the exhaust ports of the cylinder heads and carry the spent mixture away from the engine, to the muffler if one is used. At approximately the end of the COMPRESSION stroke for each cylinder, a spark plug is used to ignite the air/fuel mixture.