Fact Friday
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
April 11, 2025
Tube sponge
Most of the time, we think of sponges as the rectangular cleaning tool next to our sink, but did you know that sea sponges are actually animals? Most sponges are sessile, meaning that they can’t move. In order to eat, they must filter feed. Sponges have specialized cells that push water through their small pores to filter out plankton and other tiny organisms.
Photo Credit: Badi Samaniego
