Right. Kaldur forgot he didn't have his jacket that usually hid his gills in his civilian clothes. He doesn't let it offend him though and he probably should have expected such a response. Kaldur is about to explain but Gizamon jumps in instead.

"Hey! Don't be rude! They're perfectly normal!" Kaldur had already explained them to Gizamon, although being a digimon she hadn't questioned it as much.

He probably should have seen that reaction coming from her though. She got rather defensive about him. "Gills. I am Atlantean, that is, I was born under the sea." In fact until about two or three years ago he'd never set foot on the surface world.