For a portrait photographer, Susan Middleton has an unusual studio. It’s mobile, for one thing, and it requires the subject to be confined in a small glass box. But the results are gorgeous.

In her new book, Spineless: Portraits of Marine Invertebrates, The Backbone of Life, Middleton gives jellyfish, nudibranchs, and anemones (among many others) the type of photographic treatment usually reserved for sports stars and heads of state. Shot against plain black or white backgrounds, the weird beauty of these creatures—many of them rare species seldom seen by human eyes—really stands out.