Bubble-tip Anemone (purple)

Entacmaea quadricolor is a species of sea anemone in the family Actiniidae. Like several anemone species, E. quadricolor can support several anemonefish species, and displays two growth types based on where they live in the water column, one of which gives it the common name, due to the bulbous tips on its tentacles.

Description

Tentacle up to 10 cm in length and are usually transparent ligth brown with bulb at or below the end. Tip of the tentacle is usually red with the equator of the bulb white. A variety of morphs includes also pink, orange, green tips. Bulb is said to be related to presence of fish and may be absent in which case tentacles have a white ring where the equator of the bulb would have formed. Shallow water specimens have small polyps with oral disc diameter about 5cm and are clustered together in crevices or adjacent to coral branches so that they appear confluent and forms an extensive field. In deep water they may reach up to 40cm diameter (oral disc) and are solitary. It obtains the majority of its energy from solar radiation via its symbiotic zooxanthellae.

Distribution

Indo-Pacific: Micronesia and Melanesia to east Africa and the Red Sea and from Australia to Japan.

Habitat

A characteristic of E. quadricolor is its ability to maintain a symbiotic relationship with the anemonefish, which can be "hosted" by the anemone by providing it with defence against predators and also providing some nourishment. In turn, the anemone provides the anemonefish with shelter. Nutrients are generally obtained by filter feeding using its sweeping tentacles, or through wastes and debris cleaned from the surface of its partner anemonefish.

In the wild, E. quadricolor are found in two locations. Large adult specimens, with tentacles that are more streaming or stringy, are often found in deeper waters with more dimly lit conditions. These specimens are often solitary, while smaller, younger specimens are often located in groups or colonies nearer to the surface, in bright sunlight. These specimens tend to show the bulbous tips on their tentacles that are characteristic of E. quadricolor. The tips of the anemones will have their characteristic bulbs based on several parameters, including; flow, light, bacterial count, color, and if its hosting.

Symbionts

E. quadricolor is found within the range of most anemonefish and is highly generalist, hosting 14 different species, around half the species of anemonefish. It is thought the primary reason it does not host other species is competition, with other factors being habitat preferences or host-fish biochemical signalling. The anemone fish hosted by E quadricolor are:

• Amphiprion akindynos (Barrier reef anemonefish)
• A. allardi (Allard's anemonefish)
• A. barberi (Barber's anemonefish)
• A. bicinctus (Two-band anemonefish)
• A. chrysopterus (Orange-fin anemonefish)
• A. clarkii (Clark's anemonefish)
• A. ephippium (Red Saddleback anemonefish)
• A. frenatus (Tomato anemonefish)
• A. mccullochi (Whitesnout anemonefish)
• A. melanopus (Red & Black anemonefish) (primarily clustered form)
• A. omanensis (Oman anemonefish)
• A. rubrocinctus (Australian anemonefish)
• A. tricinctus (Three-band anemonefish)
• Premnas biaculeatus (Maroon anemonefish) (only solitary form)

E. quadricolor also associates with juvenile Dascyllus trimaculatus and shrimps.

Aquaculture

In aquariums, E. quadricolor will reproduce asexually or sexually when in proper care with supplemented minerals such as iodine and other trace elements, usually purchased as an enrichment cocktail by most home aquarists. E. quadricolor is commonly kept in marine aquariums and comes in variety of colours, green being the most common.