These were taken at the Monterey Aquarium a few weeks ago.
There is a wonderful seahorse exhibit and the one in the photo above is called a Leafy Sea Dragon. Great camouflage don't you think? They are found off the coast of southern and western Australia. If I could have pulled a comfortable chair up next to the exhibit I would have stayed there studying them for a couple of hours or more, just fascinating.
The red shrimp above is called a Pacific Cleaner Shrimp.
All the seahorses I saw were just the most graceful and beautiful things. I can see why they say people who have fish tanks have low blood pressure. You look at these wonderful creatures for any length of time, you become totally relaxed. Maybe that's why they don't supply easy chairs at aquariums. We'd all be taking a nap.
This is a video of the Weedy Sea Dragon, not quite as showy as the other but still very beautiful. They are also found off the coast of southern Australia. You can find more about them here.
This is a horseshoe crab. He was pretty small. I found an article about them on Wikipedia too, which you can read about here.
Thank you 2sweetnsaxy for hosting this great meme.