Hexabranchus sanguineus - Spanish Dancer

The Spanish Dancer is a shell-less marine gastropod belonging to the family Hexabranchidae. Its broad mantle normally curls upward around the outer edge while the animal crawls across the reef.

Two retractile rhinophores are located at the front, while six separately retractile, feather-like gill plumes form the dorsal gill structure near the rear.

Key features

• One of the world’s largest nudibranchs
• Scientific name: Hexabranchus sanguineus
• Common name: Spanish Dancer
• Family: Hexabranchidae
• Red, orange, pink or white-patterned body
• Broad, strongly folded mantle edges
• Six separate feather-like gill plumes
• Retractile rhinophores
• Swimming motion resembles a swirling flamenco skirt
• Native to the tropical Indo-Pacific and Red Sea
• Adult size commonly approximately 20–40 cm
• Exceptional maximum size approximately 60 cm
• Primarily nocturnal
• Completely peaceful
• Specialised sponge feeder
• Does not graze algae
• Not a clean-up-crew animal
• Does not normally accept standard aquarium foods
• Reef safe only with caution
• May consume ornamental sponges
• Requires a continuous supply of suitable sponge food
• Sensitive to copper and medications
• Must be protected from pumps and overflows
• Recommended only for experienced marine aquarists

Care information

• Adult size: commonly approximately 20–40 cm
• Maximum size: approximately 60 cm
• Diet: selected sponge species
• Activity: primarily nocturnal
• Temperament: peaceful
• Reef compatibility: with caution
• Care level: extremely difficult
• Origin: Red Sea and tropical Indo-Pacific
• Natural habitat: sponge-rich rocky and coral reefs
• Natural depth: approximately 1–50 metres
• Recommended minimum aquarium volume: approximately 300 litres
• A substantially larger aquarium is preferred for a full-grown specimen

Suggested water conditions

• Temperature: approximately 22–26 °C
• Specific gravity: approximately 1.023–1.026
• pH: approximately 8.1–8.4
• Alkalinity: approximately 8–12 dKH
• Ammonia: 0 mg/l
• Nitrite: 0 mg/l
• Flow: moderate and indirect
• Lighting: low to moderate
• Oxygenation: high

Feeding

Identify the sponge consumed by the individual before purchase. Maintain a continuous supply of the same or another confirmed food sponge and replace the food source before it is completely consumed.

Ordinary fish food, frozen seafood, coral powders, phytoplankton, zooplankton and algae sheets do not reliably replace the natural sponge diet.

Introduction

1. Protect all pump and overflow intakes.
2. Confirm that suitable sponge food is available.
3. Dim the aquarium lighting.
4. Equalise the transport-water temperature.
5. Acclimate gradually to salinity and water chemistry.
6. Maintain temperature and oxygenation during acclimation.
7. Avoid unnecessary exposure to air.
8. Do not handle the animal with bare hands.
9. Transfer it underwater in a sufficiently large container.
10. Place it onto stable rock beside the identified food sponge.
11. Temporarily reduce strong water flow.
12. Confirm that the muscular foot attaches securely.
13. Monitor feeding, movement and body condition closely.
14. Avoid all copper-based medications.