Care
The Hammerhead Euphyllia, also known as Anchor Coral, is a beautiful large polyp stony (LPS) coral that is known from sheltered, soft-sediment reef slopes at depths of up to 30m (98ft). The common name reflects the shape of the ends of the tentacles, which closely resemble hammers or anchors. These translucent tentacles are completely retractable and may be brown or green (and very occasionally orange or purple) in colour, often with contrasting colour tips. They are extended fully by day, hiding the flabello-meandroid(curving, wall-like) skeleton beneath. In the aquarium, Hammerhead Euphylliaare excellent water quality monitors - though they are considered relatively hardy, failure to show good polyp expansion can indicate less-than-perfectwater conditions. Be aware that colonies can spread to more than 50cm, and sometimes even attain a size of around 1m, so a very spacious aquarium is required. In the wild, these corals prefer somewhat turbid conditions and will thrive in the aquarium with bright but indirect light and a gentle current. The current should be sufficient enough to keep any detritus from settling on top of the coral, but not so vigorous as to prevent it from expanding its polyps or causing tissue damage from being pushed against its own sharp skeleton. As Hammerhead Euphyllia produce long sweeper tentacles tipped with potent nematocysts, careful positioning is vital so that they do not damage neighbouring corals; very few sessile invertebrates survive repeated aggressive attacks by members of the Euphylliagenus, and these sweepers can extend out some 21cm (8.3"). It is worth noting that these corals will be more inclined to form multiple sweeper tentacles if the current is especially strong, so such unfavourable conditions are to be avoided. Having said this, it should be mentioned that some Euphyllia species can be arranged fairly close together, even touching, without problems. The Hammerhead Euphyllia (E. ancora) is regularly and successfully kept close together with branching Hammerhead Euphyllia (E. paraancora)by many aquarists. However, do not attempt to house the Torch Coral (E. glabrescens) close to any other psyllids as it will not tolerate them and will engage in stinging warfare. It is not uncommon for some large Hammerhead specimens to become substitute homes for clownfish if there is no suitable anemone present for them to live in. When a clownfish first decides to take up residence, the coral may not extend its tentacles as fully as usual, but they generally becomes accustomed to the presence of such fish within a matter of days and revert to their normal behaviour. Smallcommensal shrimps such as Periclimenessp. and Thor sp. may often come in on these corals and are harmless. Unfortunately, Hammerhead Euphyllia does seem to be a little prone to "brown jelly" infections (an attack on injured flesh by various micro-organisms), possibly as a result of hermit crabs lumbering over them in their ongoing search for food items. Whenever you have to handle Hammerhead Euphyllia, do so only by the skeleton, as stings from contact with the tentacles can be particularly painful. Always try to ensure you purchase aquacultured specimens wherever possible, to take pressure off the reefs.
Feeding
This species is zooxanthellate, but it is a voracious feeder that will benefit from feeding with small meaty food items such as Mysis shrimp, vitamin-enriched brine shrimp, chopped clam etc. several times per week. When supplementing its diet with these meaty items, do keep a close eye on water quality.
Propagation
Hammerhead Euphyllia has separate male and female colonies, and can release eggs and sperm for external fertilisation in the water column. Under favourable conditions in the aquarium, this species is more likely to reproduce by budding, with small polyps emerging from the base of the colony.
