Hammer Coral (Euphyllia ancora) Care Guide

Euphyllia ancora is an Indo-Pacific LPS coral with T-shaped hammer-tipped tentacles, kept in moderate light and flow with stable reef chemistry.

Overview

Euphyllia ancora (reclassified as Fimbriaphyllia ancora in 2017) is a large-polyp stony (LPS) coral in the family Euphylliidae, native to the Indo-West Pacific. Polyps display puffy tubular tentacles with characteristic T-shaped 'hammer' or 'anchor' tips that sway in moderate flow. The IUCN currently lists the species as Vulnerable.

Taxonomy

Family: Euphylliidae
Genus: Euphyllia (current trade name) / Fimbriaphyllia (2017 revision)
Scientific name: Euphyllia ancora
Common names: Hammer Coral, Anchor Coral
Growth form: branching and wall morphs

Habitat

Found throughout the Indo-West Pacific from the Maldives to the Solomon Islands, with significant populations in Indonesia and Australia, typically on reef slopes and lagoon walls at moderate depth. Spawning is synchronous on the third and sixth nights after a full moon during neap tides; detached tentacle tips can also form new colonies.

Tank requirements

Minimum tank maturity: 3 months
Temperature: 24-26 C (75-79 F)
Salinity: 1.024-1.026 SG
pH: 8.1-8.4
Alkalinity: 8-11 dKH
Calcium: 400-450 ppm
Magnesium: 1280-1350 ppm
Phosphate max: 0.03 ppm
Nitrate max: 5 ppm
Lighting: 75-175 PAR (medium)
Flow: medium and indirect

Placement

Place in the lower-to-mid reef where flow is gentle and indirect. Leave 10-15 cm clear of other corals: Euphyllia produce stinging sweeper tentacles that damage non-Euphyllia neighbours. Hammer, Frogspawn and Torch (all Euphyllia/Fimbriaphyllia) tolerate close proximity to one another.

Feeding

Symbiotic zooxanthellae supply most energy via photosynthesis; supplementary spot-feeding 1-2 times per week with mysis, brine shrimp, reef-roids or amino acids accelerates growth and tissue health. Feed only when polyps are extended and flow is briefly reduced.