Eggs
Released in open water at dusk, they are pelagic.
Four-stage life cycle
Butterflyfish
A flat fish with strikingly visible patterns
An emblem of coral reefs, the butterflyfish often lives in a faithful pair and feeds on coral polyps.
Life cycle (4 stages)
Larva
A tholichthys larva, protected by bony plates, drifting for several weeks.
Juvenile
The young settles in the reef and often displays a deceptive eyespot.
Adult
It forms a lasting pair and defends a coral territory.
Physical changes
- Very flat, rounded body, ideal for slipping between coral branches.
- Elongated snout to reach polyps.
- Black band masking the eye and a false eye near the tail.
- Highly contrasted yellow, white and black patterns.
Habitat
- Coral reefs
- Lagoons
- Outer slopes
- Clear shallow waters
Diet
- Coral polyps
- Small invertebrates
- Tube worms
- Algae
- Zooplankton
Survival adaptations
- Fine snout to pick inside crevices.
- Eyespot near the tail diverting attacks.
- Living in pairs to watch the territory together.
- Flat body giving great manoeuvrability.
Ecological importance
- Regulating the growth of certain corals
- Acting as a bio-indicator of reef health
- Feeding reef predators
Importance
- Type : Reef bony fish (Chaetodontidae family)
- Habitat shift : Pelagic eggs → Tholichthys larva → Reef juvenile → Territorial paired adult
- Role : Coral specialist and reef sentinel.
- Scientists count butterflyfish to assess reef health: their decline announces reef degradation.
Did you know?
Many butterflyfish stay paired for life and always swim within a few centimetres of each other.