Challenge

I always get a little bit confused when students ask me, "What is your hobby?".  It appears that they expect a person to only have one hobby.  I, and most of my friends, are interesting in a number of things and spend a little bit of time doing a lot of different things.  I like, cooking, watching movies, taking pictures, swimming, cycling, gardening, reading, sailing, playing frisbee, yoga, badminton, hanging out with friends, traveling, hiking, and scuba diving. If it is interesting or fun, I'll probably do it.  I've just taken up tennis and went rock climbing a couple of times recently and thought it was really fun. 

Anyway, one of my hobbies (actually a couple of them combined) is responsible for the picture above.  I took the picture when I was on vacation in the Philippines, 12 meters below the surface of the ocean on a dive.  If you are one of the first five people to identify the creature you will receive ten points.  Hint: some of the relatives of this kind of animal have a shell.
Here is a different one.  It is the same type of creature, but a different species: