Hexabranchus sanguineus
- Kingdom
- Animalia
- Phylum
- Mollusca
- Class
- Gastropoda
- Order
- Nudibranchia
- Family
- Hexabranchidae
- Genus
- Hexabranchus
- Species
- Hexabranchus sanguineus
Hexabranchus sanguineus, the Spanish dancer, is one of the largest nudibranchs in the world. It is a dorid in the family Hexabranchidae and can grow well over 20 cm long, with some animals much larger.
Adults are usually bright red to orange-red, often with a paler or white edge to the broad mantle. Its gills sit in separate pockets on the back, which is where the genus name, meaning six gills, comes from. When disturbed it can lift off the bottom and swim by flexing its body and flapping the mantle edges, the dance that gives it its common name.
It feeds on sponges and lays large, rose-shaped red egg ribbons that are easy to spot on the reef. Look closely at the animal too, because it is often host to the emperor shrimp, a small commensal shrimp that rides on its back.
In the Philippines it is most often seen on night dives, when it crawls in the open. Photographers should keep a respectful distance and avoid triggering a swim, since swimming costs the animal a lot of energy.
It appears on page 29 of Nudibranchs of the Philippines.
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