From sea + urchin(“hedgehog”), reflecting a similarity in appearance to a hedgehog.
Pronunciation
Lua error in Module:parameters at line 290: Parameter 1 should be a valid language or etymology language code; the value "GA" is not valid. See WT:LOL and WT:LOL/E.enPR: sēʹ ûr'tsĭn, IPA(key): /ˈsi ˌɝtʃɪ̈n/
1986, Patrick S. Leahy, Chapter 1: Laboratory Culture of Lua error in Module:taxlink at line 68: Parameter "ver" is not used by this template. Adults, Embryos, and Larvae, Thomas E. Schroeder (editor), Methods in Cell Biology, Volume 27: Echinoderm Gametes and Embryos, page 2,
Of the many species of sea urchins utilized in biological research today the most widely used in North America is probably the purple sea urchin, Strongylocentrotus purpuratus.
2001, V. L. Kasyanov, Reproductive Strategy of Marine Bivalves and Echinoderms, page 90,
The pericentriolar radial complex characteristic of the spermatozoa of other echinoderms is lacking in the spermatozoa of all sea urchins.
2004, Belinda J. Sly, The Development and Evolution of the Echinoderm Nervous System, page 9,
Approximately 20% of sea urchins are direct-developers, meaning that they bypass the pluteal larval stage and develop directly into an adult sea urchin.