The sea swallow goes by many names, blue angel, blue dragon, blue ocean slug and blue sea slug. You can see from the pictures that these names make sense. Sea swallows are really weird creatures, they float in the water upside down and they have an organ filled with gas which helps them do this. They eat things that sting, like the portuguese man o' war and the blue button, shown in the picture bellow.
Because they swim upside down, their top half is silver to blend in with the water's surface from beneath and their bottom half is blue so that they can blend in with the blue water from above. They can also sting worse than a man o' war because they store the stinging parts of their prey in their cerata, which are the things that look like wings, which they also use for breathing so to speak.
There are no males or female, but they are both together and when they come together to mate both the slugs will have eggs. Altogether they are pretty weird and cool looking and can be found in the warm waters of the Indian, Atlantic and Pacific oceans.
Hope you enjoyed the post!!!!