Starfish are now known as sea stars and jellyfish are now known as sea jellies. Sometimes jellyfish are referred to as just jellies, but I prefer sea jellies, this name better orients the mind.

Why the switch? Jellyfish aren’t fish, making the name sea jellies more accurate, but the new term is having a tougher time catching on compared to sea star. So for the purposes of this blog I will be using both names to avoid confusion and also help people transition.

Sea jellies are members of the phylum Cnidaria (the C is silent) and also members of the subphylum Medusozoa. Their bodies are made up of mesoglea, a jelly-like material. According to Jellyfishfacts.com a “jellyfish has two layers of skin – epidermis or the outer layer and gastrodermis or the gut lining. A layer of thick gelatinous substance called mesoglea fills the portion between these two skin layers.” Mesoglea gives sea jellies much of their substance, which isn’t much considering they are 95% water.

Mesoglea is another great science name that actually makes sense. Thefreedictionary.com explains that meso is Greek for middle and glea derives from the ancient Greek work gloia meaning glue. And that’s exactly what mesoglea is, the glue holding together a sea jelly’s middle layer.