Author: Maria Azcapri
Article inspired on the amazing work done by Ocean. Juan Carlos Azcarate, my beloved bro.
Iyob (Job) 38:16 Have you traveled to the sources of the sea or walked in the depths of the oceans?
The first critters on earth, or at least, the longest living, are the Medusae (Jellyfish). According to modern scientists, the very first one was the ocean-drifting comb jelly, not the less complex sponge, as it was believed.
Medusae are composed of more than 90% water, and a mass of a gelatinous material, called mesoglea, which is surrounded by two layers of cells which forms the umbrella, top surface, and the bottom surface, the subumbrella, known as the bell.
Unlike sponges, comb jellies have connective tissues and a nervous system, they lack of brain and of a central nervous system, instead they are made with a nerve net. Their skin is so thin, that they are oxygenated by diffusion, and they can be found in every ocean, from the depths, to the surface.