Spanish Dancer

Scientists that identify, describe, classify and name organisms (taxonomists) can sometimes be a bit plain when naming species. However, there are some exceptionally creative names, and one of them is Spanish dancer (Hexabranchus sanguineus), an elusive species of Indo-pacific nudibranch.

Our Mr Friday Gasim, found one of these stranded on Gili beach, and called me to assist. We released the creature into a deeper part of the lagoon, and since it was in good health we did a photoshoot. What a beauty!

Nudibranchs are sea slugs, which, as their Latin name implies, have naked (exposed) gills. These sea slugs often have beautiful colours and are admired by many divers and snorkelers alike. Spanish dancer has a striking red colouration, and when it swims, it truly looks like an exotic flamenco dancer (or at least an underwater version of it). Nudibranchs are often small, however Spanish dancer is an exception – it is one of the largest nudibranch species in the world, growing over 40 cm in length.
Despite the size, the Spanish dancer is a rare sight, since it is primarily nocturnal. It much more common to see the eggs of this animal. Eggs of Spanish dancer are very distinctive and are seen more commonly than the nudibranch itself, they are laid in a beautiful egg rose, which also resembles a skirt of a Spanish dancer.

Egg rose of a Spanish Dancer (picture is a kind contribution of our guest).

While some nudibranchs are herbivorous, many others have bizarre specialized diets consisting of either bacteria, sponge, jellyfish, anemones, coral, sea pens, flatworms, barnacles, crustaceans, tunicates, eggs, or even other nudibranchs. Spanish Dancer eats toxic sponge Halichondria sp. and finds it’s food with two sensory organs on the front of their body. The nudibranch then accumulates the toxins from it’s food, and incorporates them into its own body and eggs, in this way the nudibranch repels any predators.

Have you ever seen a Spanish Dancer?