A River Tube Shark. You wonder how Tube Sharks propel themselves. They use a tube. They use water through the tube to shoot water out of the other end causing them to move. The River Tube Shark feeds off of small river fish. They normally guard Skrewlixes because they feed off of things that get stuck on their teeth. Only some species of screwlixes feed this way. Let me tell you about the tube shark lifecycle. Tube sharks begin as small eggs, connected by strands that are connected to rocks or river banks. Then they hatch into baby tube sharks. Baby tube sharks feed off of small worm like creatures that live in the water and maybe off some baby fish. Then slowly grow into the adult tubeshark. Then the tube shark goes through an interesting metamorphosis. The female become faster and produce more eggs and become bigger. The males burst open releasing the fertilisers. These are smaller tube sharks whose only purpose is to store the sperm the tube shark made and then the fertilisers releases sperm fertilising the eggs and the life cycle continues. The fertilisers die after a few days and have small mouths feeding off the worm things the baby tube sharks eat.