Ten sea urchin species compared through real photographs of their spines, outlines and colours. An editorial selection, not a danger ranking. Attribution: 1. File:Diadema setosum Oman.JPG; Frédéric Ducarme; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0; https://commons.wikimedia.org/wiki/File:Diadema_setosum_Oman.JPG; Scaled without cropping; fitted into 9:16 with title and caption bars. 2. File:Falso erizo de fuego (Astropyga radiata), Zanzíbar, Tanzania, 2024-06-01, DD 99.jpg; Diego Delso; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0; https://commons.wikimedia.org/wiki/File:Falso_erizo_de_fuego_(Astropyga_radiata),_Zanz%C3%ADbar,_Tanzania,_2024-06-01,_DD_99.jpg; Scaled without cropping; fitted into 9:16 with title and caption bars. 3. File:Heterocentrotus mammillatus in situ from Hawaii.JPG; Scott Roy Atwood; CC BY-SA 3.0; https://creativecommons.org/licenses/by-sa/3.0; https://commons.wikimedia.org/wiki/File:Heterocentrotus_mammillatus_in_situ_from_Hawaii.JPG; Scaled without cropping; fitted into 9:16 with title and caption bars. 4. File:Collector urchin.jpg; Diver vincent; CC BY-SA 3.0; https://creativecommons.org/licenses/by-sa/3.0; https://commons.wikimedia.org/wiki/File:Collector_urchin.jpg; Scaled without cropping; fitted into 9:16 with title and caption bars. 5. File:Erizo de mar (Mespilia globulus), Anilao, Filipinas, 2023-08-22, DD 283.jpg; Diego Delso; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0; https://commons.wikimedia.org/wiki/File:Erizo_de_mar_(Mespilia_globulus),_Anilao,_Filipinas,_2023-08-22,_DD_283.jpg; Scaled without cropping; fitted into 9:16 with title and caption bars. 6. File:Echinus esculentus Koster.jpg; Bengt Littorin; CC BY 2.0; https://creativecommons.org/licenses/by/2.0; https://commons.wikimedia.org/wiki/File:Echinus_esculentus_Koster.jpg; Scaled without cropping; fitted into 9:16 with title and caption bars. 7. File:Paracentrotus lividus profil.JPG; Frédéric Ducarme; CC BY-SA 3.0; https://creativecommons.org/licenses/by-sa/3.0; https://commons.wikimedia.org/wiki/File:Paracentrotus_lividus_profil.JPG; Scaled without cropping; fitted into 9:16 with title and caption bars. 8. File:Colobocentrotus atratus.jpg; Dayna Bubenicek; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0; https://commons.wikimedia.org/wiki/File:Colobocentrotus_atratus.jpg; Scaled without cropping; fitted into 9:16 with title and caption bars. 9. File:Echinothrix calamaris2.jpg; Anders Poulsen, Deep Blue ( http://www.colours.dk/ ); CC BY-SA 3.0; https://creativecommons.org/licenses/by-sa/3.0; https://commons.wikimedia.org/wiki/File:Echinothrix_calamaris2.jpg; Scaled without cropping; fitted into 9:16 with title and caption bars. 10. File:Phyllacanthus imperialis Maldives.JPG; MDC Seamarc Maldives; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0; https://commons.wikimedia.org/wiki/File:Phyllacanthus_imperialis_Maldives.JPG; Scaled without cropping; fitted into 9:16 with title and caption bars.