Starlet sea-anemone Nematostella vectensis
A tiny anemone rarely more than 1.5 cm in length. Translucent and colourless in appearance except for variable patterns of opaque white on the column and disk. Tentacles large in proportion to the body, colourless and translucent with pale tips and with faint transverse bars and irregular flecks of white. Image: Robert Aguilar, Smithsonian Environmental Research Center (Flickr).