Bubble-tip anemone (''Entacmaea quadricolor'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

sea anemone Sea anemones ( ) are a group of predation, predatory marine invertebrates constituting the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemone ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Actiniidae Actiniidae is the largest family (biology), family of sea anemones, to which most common, temperate, shore species belong. Most members of this family do not participate in symbiosis, symbioses with fishes. Three exceptions are the bubble-tip an ...

. 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.

Distribution

''Entacmaea quadricolor'' is widespread throughout the

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

waters of the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

area, including the

Red Sea The Red Sea is a sea inlet of the Indian Ocean, lying between Africa and Asia. Its connection to the ocean is in the south, through the Bab-el-Mandeb Strait and the Gulf of Aden. To its north lie the Sinai Peninsula, the Gulf of Aqaba, and th ...

. ''E. quadricolor'' anemones appear in a variety of morphs, including rose, orange, red, and standard green. This sea anemone can grow to be up to in diameter, and obtains the majority of its energy from

solar radiation Sunlight is the portion of the electromagnetic radiation which is emitted by the Sun (i.e. solar radiation) and received by the Earth, in particular the visible light perceptible to the human eye as well as invisible infrared (typically p ...

via its symbiotic

zooxanthellae Zooxanthellae (; zooxanthella) is a colloquial term for single-celled photosynthetic organisms that are able to live in symbiosis with diverse marine invertebrates including corals, jellyfish, demosponges, and nudibranchs. Most known zooxanthell ...

. A characteristic of ''E. quadricolor'' is its ability to maintain a

symbiotic Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biolo ...

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 Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, typically by having the water pass over or through a spe ...

using its sweeping

tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

s, 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

s 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. When they are placed in home aquariums, medium flow and medium lighting will be sufficient if your tank is old enough to captivate anemones.

Symbionts

Ancylomenes longicarpus on bubble anemone

''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 and 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

shrimp A shrimp (: shrimp (American English, US) or shrimps (British English, UK)) is a crustacean with an elongated body and a primarily Aquatic locomotion, swimming mode of locomotion – typically Decapods belonging to the Caridea or Dendrobranchi ...

s such as '' Periclimenes brevicarpalis''.

Reproduction

Sexual reproduction

''E. quadricolor'' exhibits a variety of reproductive strategies. The most common strategy would be a form of sexual reproduction called broadcast spawning. This is considered the main form of reproduction and occurs at the start of the year between January and April for those in eastern Australian waters. During these times, ''E. quadricolor'' will release its

gamete A gamete ( ) is a Ploidy#Haploid and monoploid, haploid cell that fuses with another haploid cell during fertilization in organisms that Sexual reproduction, reproduce sexually. Gametes are an organism's reproductive cells, also referred to as s ...

s into the

water column The (oceanic) water column is a concept used in oceanography to describe the physical (temperature, salinity, light penetration) and chemical ( pH, dissolved oxygen, nutrient salts) characteristics of seawater at different depths for a defined ...

and form free-swimming planula larvae. These larvae of ''E. quadricolor'' have been observed to survive up to 59 days in the water column, with peak settlement occurring around 10 days. This time of suspension allows for greater dispersal and increases genetic diversity for the species. Once the larvae settle, they will then begin to further develop and start the cycle once more.

Asexual reproduction

''E. quadricolor'' can also reproduce asexually. For most anemone species,

asexual reproduction Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the f ...

may occur by

pedal laceration Pedal laceration is a type of Fragmentation (reproduction), fragmentation (asexual reproduction) exhibited in sea anemones. In this process, a fragment of the pedal disc, which connects the anemone to its substrate, detaches from the original and d ...

, longitudinal fission, or transverse fission. ''E. quadricolor'' will occasional reproduce asexually using longitudinal fission, but this is on rare occasions. This form of reproduction allows for quick reproduction of successful

genotype The genotype of an organism is its complete set of genetic material. Genotype can also be used to refer to the alleles or variants an individual carries in a particular gene or genetic location. The number of alleles an individual can have in a ...

s but will also lead to genetic isolation and reduced dispersal as individuals are likely to attach to the first hard surface they encounter.

Aquaculture

aquarium An aquarium (: aquariums or aquaria) is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. fishkeeping, Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquati ...

s, ''E. quadricolor'' will reproduce asexually or sexually when in proper care with supplemented minerals such as

iodine Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at , and boils to a vi ...

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 colors, green and rose being the most common. Without adequate lighting, the anemone will expel its photosynthetic symbiotic zooxanthellae, a process commonly known as "bleaching" which will progressively result in its death. White or excessively translucent specimens are likely in various phases of bleaching and should not be purchased. Anemones are not easy to keep, and require a knowledgeable aquarist. The aquarium must be at least six months old and stable to receive the anemone. The bigger the tank, the easier it will be to keep a healthy anemone. File:Entquadricolor2.jpg, A group of individuals File:Entacmaea quadricolor in Tropicarium-Oceanarium Budapest 02.JPG, Rose File:Entacmaea quadricolor (Bulb Tentacle Sea Anemone).jpg, Green tipped File:Quadricolor.jpg, Bleached (unhealthy)

Conservation and threats

''E quadricolor'' is not currently listed on the

IUCN Red List of Threatened Species The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological spe ...

, but it is facing hardships with global

climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

and anthropogenic activities. Anthropogenic activities have increased atmospheric carbon dioxide and consequently global temperatures are predicted to raise by 4.3 °C while seawater pH is likely to decrease by 0.3 units. It has been observed that future ocean temperatures will cause bleaching in ''E. quadricolor,'' whereas increased ''p'' generally had no significant effects on the anemone. Coral bleaching events will have detrimental impacts on host sea anemones and the symbionts as a result of climate change.

References

External links

Entacmaea quadricolor
in Encyclopedia of Life * {{Taxonbar, from=Q881805 Actiniidae Cnidarians of the Indian Ocean Cnidarians of the Pacific Ocean Taxa named by Friedrich Sigismund Leuckart Animals described in 1828