Rainbow is a description, not a registered strain, so one seller's rainbow may look nothing like the next. Listings generally show a green base grading through orange into pink or magenta tips, most sold as aquacultured splits. Price sits well above a green bubble tip, and the gradient shifts as the animal settles into your lighting.
In the wild
Rainbow bubble tips are captive-propagated color morphs of the same Indo-Pacific anemone, spread by splitting rather than by breeding. No founder colony, breeder or year is documented for the name, and vendors are plainly working from different parent animals. Stock is sold as aquacultured, which matches how these anemones reproduce in tanks: asexual division rather than spawning.
Good to know
The multi-color effect comes from several pigment proteins expressed at different points along each tentacle, with symbiotic algae adding brown underneath. Propagation is by fission, so a rainbow's splits are clones and hold the pattern, unlike a bred fish line that segregates. Color balance still moves with the light spectrum the animal is grown under.
Did you know
Reef Builders made the point with a named strain: Chicago Sunburst anemones grown under LEDs come out bright yellow-orange, while the same strain under metal halide runs nearly all red. Much of what looks like a color phase in a rainbow listing is really the lighting it was photographed under.
Symbiotic relationships
Clownfish and their host anemones
A clownfish lives inside an anemone that stings and eats other fish its size. Its mucus coat keeps the anemone's stinging cells from firing, and a new fish builds that protection up over hours of brief touches. The fish gets a refuge no predator will follow it into and a nest site at the anemone's base. The anemone gets a guard that drives off the butterflyfish that would graze its tentacles, a steady supply of nitrogen from the fish's waste, and water movement at night, when the fish fans its fins among the tentacles and the anemone takes up more oxygen. Only ten anemone species host clownfish in the wild, and each clownfish species uses its own short list of them.
Captive-bred clownfish have never seen an anemone and do not need one; they settle for a coral, a powerhead or a corner of the tank. If you want the pairing, the anemone is the harder animal by far and goes in first, into a mature tank with strong light and stable water, at the tank size its own profile lists. The bubble tip anemone is the hardy host, and the one most clownfish accept in captivity even when it is not a natural host, so a clownfish profile lists it as the usual tank host where that is the case. The sebae, magnificent and carpet anemones are marked difficult, and the carpets eat fish. Expect a paired clownfish to defend its anemone against everything else in the tank.
Several small crustaceans live where almost nothing else can: among the tentacles of an anemone. Sexy shrimp perch in the tentacles in a cluster, bobbing their tails in the display that named them. The white-spot anemone shrimp is near transparent apart from its spots and lives on carpet anemones. The porcelain anemone crab sits at the anemone's edge and filters plankton from the water with two fan-like arms. Pederson's cleaner shrimp lives in the Caribbean corkscrew anemone and cleans fish from there. In every case the anemone is a bodyguard: its sting keeps off the small fish that would eat the shrimp. The anemone gains little, and the white-spot shrimp will nibble its host's tentacles when it is hungry.
Give each of them its anemone. Sexy shrimp take a rock flower anemone, a bubble tip or a carpet. The white-spot shrimp and the porcelain crab want a carpet anemone or a long tentacle anemone, both of which need a mature tank at the tank size their profiles list. Pederson's shrimp wants a corkscrew anemone or a condy. Without a host they perch on a coral or hide in the rock and are picked off by any fish that eats shrimp, so they suit a peaceful nano reef. A clownfish will evict them from an anemone it has claimed.
Is a Rainbow bubble tip anemone a different species from the Bubble tip anemone?
No. A Rainbow bubble tip anemone is a variety of the Bubble tip anemone, Entacmaea quadricolor, and it wants the same tank, water and food as the species.
What size tank does a Rainbow bubble tip anemone need?
A Rainbow bubble tip anemone needs at least 30 gal (115 L). It spends most of its time in the bottom.
How big does a Rainbow bubble tip anemone get?
An adult Rainbow bubble tip anemone reaches about 11.8 in (30 cm).
