Design a bug that lives under water

My mom bought me a book that told me to design a bug that lives under water. It is a book of puzzles.

My bug has spikes to make it go fast under water.
My bug has legs to walk on land. That makes it an amphibian.
My bug has gills to breath under water. They are red in my picture.
My bug has lungs to breath outside the water. You can't see them.
My bug has fins to help it swim.
My bug has antennae to help it see. It has eyes on the antennae.
My bug is luminescent like a firefly so that it can light up the water.
My bug has sharp teeth to eat small fish. That makes it a carnivore.
My bug is colorful to scare predators away.
My bug has a big nose to smell with.

Can you design a bug that is capable of living under water? If so send a link to the picture in the comments so I can see your bug.