Spanish dancer slug is a breathtaking underwater sight

Spanish dancers are a spectacular sight as they swim through the ocean. They spend most of their lives crawling over the sand or coral, eating sponges. But occasionally, they make their way through the water by undulating and flapping in a motion that is completely mesmerizing.

This incredible specimen was one of several in a patch of reef, found in Fiji. Several were observed as they slowly made their way across the coral. But one was swimming freely, flapping like the skirts of a flamenco dancer. These are impressive creatures with brilliant colour. They are truly a sight to behold when they are in motion like this.

The Spanish dancer is one of the largest sea slugs, capable of reaching 60cm (24 inches) in length. Most commonly, they are 20-30cm (8-12 inches) long. They are poisonous and few creatures are capable of consuming them.

The feathery structures on the back of this slug are external gills, used to filter oxygen from the water.