A small red blob sits in a crevice near a rockpool. Underwater, a similar-looking animal opens into a ring of red tentacles. The Australian Museum describes these as two ordinary appearances of a Waratah Anemone, an animal named after a flower rather than a flowering plant growing on the shore.
Retraction helps during exposure to air
At low tide, an exposed Waratah Anemone draws in its tentacles, reducing the surface exposed to air. When covered by enough water, it can open out to feed. The Museum places this brown-red species along southern Australian shores and identifies it as a conspicuous anemone on Sydney’s rocky coast.
The important condition is whether the animal is exposed or remains submerged, not simply what the tide table says. A pool can retain water while nearby rock is uncovered. Two animals close together may therefore present different appearances at the same time.
A closed animal is not automatically dead or in need of water poured over it. Do not prod it to make the tentacles appear or move it into a pool. Leave its position and the water around it unchanged.
The petals are food-catching equipment
WA’s Marine Waters resource explains that anemones belong to the cnidarians, the group that also includes corals and sea jellies. An anemone’s mouth is surrounded by tentacles; its attachment surface is the basal disc. The flower-like appearance conceals an animal body with a cavity inside.
The tentacles carry specialised stinging structures called nematocysts. Marine Waters describes small prey being captured and passed to the mouth. A tentacle ring is therefore part of a feeding system, not a set of petals collecting a visitor for pollination.
The same resource distinguishes the attached polyp body form from a free-swimming medusa form seen in many sea jellies. Anemones remain polyps; they do not need to turn into a jellyfish to become adults. Appearing attached also does not mean all anemones are incapable of movement: the resource describes movement using the basal disc.
An intertidal home changes around its occupant
Marine Waters describes rocky shores as a patchwork of exposure to air, wave action, drying, temperature and salinity. Different parts of the shore are submerged for different amounts of time. The animals present reflect those conditions as well as the surfaces available for attachment.
Do not assume a comfortable-looking pool is a suitable place to put an animal taken from another crevice. A small move changes its immediate surroundings, and the existing animal is not a specimen to rearrange for a photograph.
The Museum also describes tiny Waratah Anemones released already developed through an adult’s mouth and attaching nearby. Small animals beside a larger one need not be loose pieces of it. Leave the group undisturbed instead of separating them to inspect it.
Watch the change without causing it
Use an existing safe, permitted observation point and avoid stepping on or touching marine life. Do not enter exposed water or a wave-washed area to obtain a closer view. If the animal is closed, let that be the observation rather than creating an opening with food or a finger.
Record the date, whether the anemone was exposed or submerged, and whether its tentacles were visible. That small amount of context makes a red blob photograph more informative, while leaving the animal to respond to its own changing shore.