Khaled bin Sultan Living Oceans Foundation
Providing science-based solutions to protect and restore ocean health
Some cnidarians switch between a polyp and a medusa body form. Corals and anemones only have the polyp stage. Jellyfish, as we think of them, are in the medusa stage, but they have a polyp stage when they are juveniles. Hydrozoans have the opposite: their adult form is a polyp, but they have a juvenile medusa stage.
Photo Credit: KSLOF, Rob Martimbeault
March 28, 2025
Crown-of-Thorns starfish (Acanthaster planci), also known as COTS, are named for their long venomous spines that cover their body and up to 23 arms. These menacing predators eat living coral and (for obvious reasons) they have few natural predators. Sometimes COTS populations can explode and completely destroy the coral on a reef. Learn more in this short education video:
Photo Credit: Ken Marks