News / Species Spotlight / Amazing Inverts - Bubble (Bulb) Anemones (06/10/15)

Amazing Inverts - Bubble (Bulb) Anemones

By John Brandt - Edited by Eli Fleishauer

In The Wild

The bulb anemone has a widespread distribution from Micronesia into the Indian Ocean and Red Sea. The typical habitat is coral reefs ranging from very shallow to at least 130 feet. This anemone is known to have symbiotic relationships with at least 13 species of clownfishes. They have very few predators, but some species of butterflyfish will consume them.

This species prefers to anchor itself to rock; most often within a hole or depression. When disturbed, this anemone has the capability to very rapidly deflate its column and retract itself to the protection of the reef structure as a defensive behavior.

In shallow reef environments, bubble anemones frequently form colonies with many individuals living in close proximity. These populations are frequently genetic clones, the result of many asexual reproductions. Anemones from deeper water are more likely to be found as solitary individuals. Deepwater specimens tend to be larger with longer tentacles.

Like other host anemones, the bulb anemone can reach a large size. This anemone may exceed 12" (30cm) in diameter, and tentacles may grow to over 5" (13cm) long. The column can be extended outwards a considerable distance from the point of attachment.

Reproduction is by sexual or asexual means. Sexual reproduction involves the release of eggs and sperm during a spawning event. Asexual reproduction is much more common and involves an individual splitting in two.

In The Aquarium

The bulb anemone is a hardy and adaptable invert for most reef aquarium environments. They do best in low nutrient, moderate light/flow scenarios, though they are pretty adaptable and can make it (and even thrive) in situations that don't fit this description exactly. Like other inverts, they like natural salinity levels and are intolerant of even trace amounts of copper. - Image on right by Bob Fenner.

Symbiotic algae and light will provide a substantial amount of nutrition for the anemone; that being said, Bubbles will generally accept a variety of meaty foods placed into the tentacles and be better for it. Just ensure that each piece isn't too big to fit through the mouth of the anemone. Start with feeding the anemone about once per week. This can be increased in frequency or quantity if the specimen appears to be getting smaller over time. If food is rejected, try a smaller size, less at a time, a different type of food, or wait a day and try again. Some anemonefishes will grab food and deliberately place it into the tentacles of the anemone. This behavior certainly makes the job f target feeding much easier for the aquarist.

Asexual reproduction is quite common in captive environments. Before the split occurs, the anemone may begin to look "odd." The oral disc may begin to widen and appear stretched or droopy. You may be able to observe the formation of a second mouth opening before the animal begins to literally divide itself.

The stinging cells (nematocysts) on the tentacles of the bulb anemone are generally pretty mild as far as anemones go, but use caution when handling anemones none the less.

The bulb anemone is an ideal choice for the aquarist who would like to observe the fascinating symbiotic relationship between this animal and the anemonefish. The Rose and green colored anemones are particularly colorful when exposed to supplemental actinic lighting. Given the potential longevity and relative easy of care for both the fish and the host anemone, the aquarist can look forward to many years of enjoyment.