A vibrant blue undescribed ctenophore, Mertensiid cydippid, seen while exploring a 450-meter contour at the southern end of the Kona Coast of the Big Island of Hawaiʻi. Ctenophores, also known as comb jellies, are characterized by eight rows of cilia, which are used for locomotion. The cilia in each row are arranged to form a stack of combs, also called comb plates. In the video, the changing rainbow of colors running down the sides of the ctenophore is being caused by light diffraction or scattering of light by the moving cilia as the ctenophore swims.