Stiliger sp.. A new species of sea slug?
I was in the Lembeh Strait in Indonesia recently, shooting macro video of tiny skeleton shrimps on a green algae stalk, when my dive guide Mamang and I noticed a small sea slug next to them.
This is a sacoglossan, a herbivorous animal commonly known as a sap-sucking slug. It pierces the algae and sucks out the sap from the cells.
Those large, clear appendages on the back are called the cerata, or kerata, and the green ducts are branches of its digestive gland. If you look closely you can see material traveling up and down those green ducts.
It’s possible this is a solar-powered slug. Some sacoglossans keep chloroplasts from the algae alive in their body, where they continue to photosynthesize the sun’s energy into sugars, a phenomenon known as kleptoplasty.
On the head you can see two black primitive eye spots, and a long pair of sensory stalks known as rhinophores. It looks like it’s lost part of one of them. You can even