At number 17 is the:
The Blue Glaucus is a type of sea slug and spend its time floating upside-down on the surface of the Pacific, Atlantic and the Indian ocean. It swallows an air bubble and lets the wind take it away. It might seem harmless because of how peaceful it is, but it is not. It has two tricks that make it so interesting. First, the colourings make it camouflage from both sides. When under the water, the gray back of this slug is hard for the animals under the water to see it. When above, the blue belly camouflages with the water. The next trick is that it feeds on a group of animals like the jellyfish especially the Portuguese Man of War jellyfish. Some sea slugs can eat dangerous things like that. Then, the poison gets transferred to the finger like fins. The small animal is only about 3 cm long!