Fauna
Invertebrate · GBIF taxon 4597235

Black-and-gold Sapsucking Slug

Cyerce nigricans

Also known as Golden-fringed Sapsucking Slug, Butterfly Sea Slug

Black-and-gold sapsucking slugs glide gracefully across sunlit coral reef flats, displaying broad, paddle-shaped cerata edged in glowing shades of gold, orange, and white. These specialized appendages mimic fluttering butterfly wings and can be detached instantly through autotomy to startle or distract hungry fish. Beneath their decorative appearance, they feed strictly on siphonous green algae, piercing the plant cell walls with a specialized radular tooth to suck out nutritious cellular fluids.

MarineHerbivorousColorful
Black-and-gold Sapsucking Slug reference
Licensed referenceKatharina Händeler, Yvonne P. Grzymbowski, Patrick J. Krug & Heike Wägele / CC BY 2.0 · cc-by
—observations
—countries
—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Key facts
Diet & prey
  • Turtle weed (Chlorodesmis fastigiata)
  • Green filamentous algae
  • Halimeda algae
Predators
  • Wrasses
  • Crabs
  • Carnivorous sea snails
ThreatsCoral reef degradation, warming ocean temperatures, and habitat loss
HabitatsShallow coral reefs, reef crests, and protected lagoons
Life spanSeveral months to 1 year
Classification
  1. FamilyHermaeidae
  2. SpeciesCyerce nigricans
Range & activity
Range data is not available yet.
Safe observation
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Safe to observe at a normal distance.
Responsible observation
  • Diving Etiquette: Maintain neutral buoyancy over reef flats to avoid crushing fragile host algae.
  • Do Not Touch: Physical handling easily triggers defensive cerata detachment, stressing the animal.
Related species
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