Beauty is Skin Deep
For several years I have worked to photograph details on the surface of sea stars and their relatives. These animals belong to the Phylum Echinodermata. The name means “spiny-skinned” and many have conspicuous spines. Most echinoderms are harmless to the human touch, and many, such as the sea stars shown in detail in this exhibit, provide an amazing array of pattern and colour unique in the animal kingdom.
In general, echinoderms have five-fold radial symmetry as adults, but if you have seen a sea cucumber, or the larva of a sea star (they are microscopic in size) then you are aware that the radial symmetry is secondary in the adult phase of most, but not all echinoderms. All echinoderms live in the ocean, and most live in shallow waters. A few species, such as our purple sea star live in the intertidal zone, but most echinoderms do not tolerate exposure to air because they possess a sensitive water vascular system. In addition to spines, echinoderms have a variety of other structures on their surfaces – tube feet upon which they glide along the ocean floor, skin gills that project out in finger-like fashion through holes in the skeleton, and tiny pincer-claw structure that protect the animal from small colonizing animals like barnacles. The images here show details of several different sea stars.