Echinometra lucunter (red rock urchin) (San Salvador Island, Bahamas)
Echinometra lucunter (Linnaeus, 1758) - red rock urchin in rocky shoreline tidal pool.
Sea urchins (regular echinoids) are starfish relatives with a pentaradially-symmetrical, subglobose, calcareous skeleton (test) covered in spines. The mouth is underneath the urchin, close to & at the water-substrate interface. Sea urchins are algae grazers - they use a pentaradially-structured jaw, called an Aristotle's lantern, to scrape algae and biofilms from hard substrates.
The yellowish-colored organism near the lower left corner is Porites astreoides - the mustard hill coral. The whitish, semicircular structures surrounding the sea urchin are Padina jamaicensis - white scroll algae (Phaeophyta).
Classification: Animalia, Echinodermata, Echinoidea, Echinometridae
Locality: immediately east of “The Notch”, eastern part of southern margin of San Salvador Island, eastern Bahamas