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
January 31, 2025
Tunicates
Although tunicates may at first glance appear to be related to sponges or sea anemones, they’re actually in the same phylum as humans and other vertebrates – Chordata. In their larval form, tunicates look like tadpoles, with a notochord and nerve chord (which become the spine and spinal cord in vertebrates).
Photo Credit: Ken Marks
