Melibe engeli

The delicate Melibe engeli actually has algae living inside it. This interesting creature has a transparent and small body. Some species of Melibe feed on shrimps, crabs or other small crustacea. Sometimes pray remains alive in the gut until it is killed by digestive juices. 

In case you did not know this before, Melibe engeli is easily recognizable because it is the only known translucent Melibe.