The 27 Best Deep-Sea Species #10: Echinothuriid Sea Urchins

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You have to go to Echinoblog for #10 because who better to write about echinoderms than Doc Echinoderm.  The quick and dirty of why these urchins make the list and begin our top 10?

The top spines in some species have big, puffy, balloon-like sacs with an offensive substancethese spines are functionally similar to hypodermic needles and may emit an offensive fluid to ward off unwanted visitors.

The Echinoblog: The 27 Best Deep-Sea Species #10: Echinothuriid Sea Urchins.