Ryan Photographic - Hexabranchidae - Spanish dancer
The family Hexabranchidae currently contans only two species, Hexabranchus sanguineus (the Spanish Dancer) and Hexabranchus morsomus. The Spanish Dancer is ubiquitous in the Indo-Pacific. It gets its name from the most common color morph and its rhythmic swimming action which ruffles and swirls the perimeter of the mantle like the petticoats on a Spanish dancer. Like many other nudibranchs it feeds on sponges. The family and generic names stem from their possession of six separate gill clusters (hexa= six, branch = gill). H sanguineus is one of the largest of the nudibranchs and may reach 40 cm in length. It is highly variable in color as evidenced in the photos below. It is possible that this is actually a species complex - I am not aware of any DNA testing having been done on the species.
Hexabranchus sanguineus Spanish dancer
Hexabranchus sanguineus Spanish dancer Kri Eco, Raja Ampat IMG_8287
Hexabranchus sanguineus Spanish Dancer Red Sea P7232140
Hexabranchus sanguineus Spanish Dancer Red Sea P7232142
Hexabranchus sanguineus Spanish dancer, Fiji
Hexabranchus sanguineus Spanish dancer eggs, Puerto Galera, Philippines.
Hexabranchus sanguineus Spanish dancer eggs close up