Echinoid Directory - Biology, phylogeny, and classification of sea urchins.
The Echinoids - Information about sea urchins, such as how they live, feed, and reproduce. There is also an alphabetic listing of their taxa. From The Natural History Museum, London.
Heart Urchin: Abatus sp. - Photographs and information on several species of heart urchin found in McMurdo Sound in Antarctica.
Loxechinus albus - Factsheet from the FAO on the Chilean Sea Urchin which is eaten in Chile and Peru, its distinguishing features, distribution, habitat and biology.
Photos of Sea Urchins - Photos of Echinoidea from the Indo-Pacific, with text about behavior, habitat, and characteristics.
Red Sea Urchin - Information from Wikipedia on this species, Strongylocentrotus franciscanus, including its description, feeding habits, behavior and reproduction.
Sea Urchin Embryo - A page from the Laboratory of Embryonic Gene Expression, included here for three beautiful photographs.
Sea Urchin Embryology - Laboratory modules using sea urchin eggs to explore fertilization and development.
Sea Urchins Revisited - Photographic study by Jean-Marie Cavanihac of the sea urchin with some microscopic features of interest to the amateur naturalist.
Sterechinus neumayeri - Photographs and information on this urchin found in Antarctica which often camouflages itself with bits of shell and debris.
Strongylocentrotus drobachiensis - Exercise from Invertebrate Anatomy OnLine covering the systematics, external and internal anatomy of the green sea urchin.
Who is in Charge Here? - Illustrated article by Richard L. Howey considering how creatures with no brains, such as the sea urchin, react appropriately to their surroundings.
