Not entirely sure what these are called but I saw them on the reef just outside of the LUX resort in the Maldives. <br /><br />They looked alot bigger when I was snorkelling!<br /><br />You can read my review about the LUX hotel and see more photos at https://www.thesonofthom.com/lux-south-ari-atoll-in-maldives/<br /><br />Find out more about my blog at https://www.thesonofthom.com