海膽
Sea urchins can be found in all climates, from warm seas to polar oceans. The larvae of the polar sea urchin "Sterechinus neumayeri" have been found to use energy in metabolic processes twenty-five times more efficiently than do most other organisms. Despite their presence in nearly all the marine ecosystems, most species are found on temperate and tropical coasts, between the surface and some tens of meters deep, close to photosynthetic food sources.