Too many mystery of Nature are yet to be uncovered, and many of these mysteries might not be solved till the next generation. Fact is , there are a million more things, animals, organisms, gases,yet to be discovered despite the thousands of different species of Animals that have been found, named, grouped and classified. The water world is where most of these things are, in the deep blue sea roams so many uncharted territory.
A Salp, the transparent fish as it's called is one of those things. It resides in the deep which covers over a third of this planet.
Otherwise known as the salpa, it is a barrel-shaped, planktic tunicate. It moves by contracting, thereby pumping water through its gelatinous body, one of the most efficient examples of jet propulsion in the animal kingdom. The salp strains the pumped water through its internal feeding filters, feeding on phytoplankton. Wikipedia
An animal, true. Likened to fishes, also true, commony found in equatorial, temperate, and cold seas, Oceans where they can be seen at the surface. They move in colony mostly attached together when travelling, and could be found alone like the guy in the image.
They have a unique function, they reduce the carbon levels in the water and in the air as well by sapping in CO2 around them. So I'll consider them a wonder and a gift for this amazing job!