Upside down jellyfish

Upside-down jellyfish are awesome. I mean, regular jellyfish are pretty cool looking, but these guys take the cake. And not the upside-down pineapple cake, but the upside-down jellyfish cake. What are they called? Cassiopea, similar to the constellation although to be honest I'm not sure if it has an extra i in the pea or not. The internet is giving me mixed results. They do excrete stinging cells, so if you get too close you might not be very happy. Just admire from afar, and you're all good.

Under the sea

Under the sea...dangers lurk beneath unexpecting swimmers. All sorts of toxic creatures live beneath cool blue Caribbean waters. Here are some of the dangerous sea creatures from Panama:

Lionfish, which are native to the Pacific ocean, have become invasive in the Caribbean and Atlantic in the last few years. They have toxic spines which means they have no predators that can eat them in the Caribbean, where they are not native. Humans can eat them though, if they remove the spines!

Portuguese man o'war. Found plenty of places other than Portugal. They look like bright purple potstickers with a tail, or some sort of weird Nerf ball. If you want a fun stinging game, try picking one up. It hurts. 

Sea urchins. Don't step on these guys. This long spined urchin is from the genus Diadema. 

Spanish dancer in the water

I saw a really cool animal yesterday in the water near the lab. At first I thought it was a piece of trash, but then I looked again and it turned out to be a nudibranch. A nudi-what? They are sea slugs, like snails without shells. Nudibranchs come in all different cool colors, but this one is bright red. Usually nudibranchs crawl across the bottom, but this one floats up in the water column and undulates its sides, so it looks like a flamenco dancer twirling its skirts. It is called a Spanish dancer (species name is Hexabranchus morsomus).