MATTHEW OLDFIELD / SCIENCE PHOTO LIBRARY MATTHEW OLDFIELD / SCIENCE PHOTO LIBRARY
Swallowtail cardinalfish (Rhabdamia cypselura) school swimming in black coral. These small reef fish form large schools, floating in the water at night to eat plankton. They reach 6 centimetres in length, and are found in the tropical Indo-Pacific region. Photographed in the Indian Ocean, off the Maldives.
Model release not required. Property release not required.