Video shows moving through ocean with bits of small shrimp or debris moving quickly past the camera. A jellyfish with extremely long tentacles comes into view in the distance. Camera moves closer until it is passing over the top of it and continues through the brine until coming in close to a second jellyfish. You can see the top flatten out and then curl under to produce forward movement. As the camera passes above, the jellyfish swimming pattern is briefly disturbed and you can clearly see the underside showing it's radial canals and mouth parts.
Voice: Jellyfish are not fish at all. The are related to corals and sea anemones. Although they have no brain or blood, they have no trouble surviving. The have been around since before the dinosaurs and can be found in every part of the world's oceans. Their bodies are mostly water, are fragile and feel a bit like jello. Threads, called tentacles, help them catch their food and hold on to it, but some stingers are just to defend themselves. Some kinds of baby fish use the tentacles of jellyfish for protection in the same way that clown fish hide in the tentacles of sea anemones.