New Children's book sketches

For our Illustrative drawing class we head to the zoo every week, these are some of the sketches done there. I am going to illustrate a children's book set underwater in the reef. The three main characters are going to be an eel, a little shark, and a jellyfish. These sketches are just from life but the next ones I put up will probably be the actual character sketches. I am pretty excited about this project so I'd love some feedback about the characters and environments as I start to put more of them up.