A tube assembly for a living organism includes a tube and a first ferrule. The tube is partially placeable into a living organism. The tube includes a first end, a second end, a through-hole, and a lens. The through-hole extends in a first direction from the second end to the first end. The first ferrule covers an outer periphery of the tube in the first direction. The lens is located in a portion of the through-hole including at least the first end. The tube and the first ferrule contain a ceramic material.