Tag Archives: anemone

Creature of the Month is the Threespot Dascyllus

If you have dived in the Red Sea, Indian or Eastern Pacific Ocean, you will probably have seen shoals of these small black fish. They live on coral and rocky reefs at depths of 1 to 55 m.

Do not rely on the name for identification. When young, the threespot dascyllus does indeed have three white spots: one on each side and one on the forehead. Adult fish lose the forehead spot, the side spots become less distinct and the black colour of the fish becoming less intense.

Youngsters often live in large sea anemones, alongside the instantly recognisable Clownfish. Adults, though, leave the anemone to congregate in small groups around prominant rocks or coral outcrops.

The groups of adult Dascyllus trimaculatus comprise around 10 individuals with one male to several females. When approached by an intruder, the male assumes a higher defensive position, while the females rest betwen the tentacles of the anemone. During spawning the male dances to attract females. They deposit eggs on coral branches which are watched and guarded by the male until they hatch.

Dascyllus trimaculatus is part of a complex of four species that vary in geographical ranges and colour patterns. Of these D. trimaculatus is the most widely distributed,

Further Reading:
Coral Reef Fishes Indo-Pacific and Caribbean, Lieske and Myers

Creature of the Month: Burrowing Anemone

burrowing anemoneThis common species – Cerianthus lloydii – is not a true anemone but a tube anemone. Instead of attaching itself to a rock it lives in a soft felt-like tube protruding above sand or mud. The anemone’s tentacles are usually all that is visible. The inner set circle the mouth and are short and stiff. The long, flexible and attractive outer ones, over 100 of them, sweep prey inwards. When disturbed the whole anemone shoots back into its tube, like a tubeworm. The tentacle crown measures up to 10 cm across.

Cerianthus lloydiiThe animals live from the shallows down to 100 m. The tentacles may be white, brown, green or banded.

You can find the burrowing anemone around the British Isles and in North West Europe to the Bay of Biscay.

Further Reading:
Great British Marine Animals, by Paul Naylor, Deltor (2003)

What do you think of this news item? Join a discussion.

Creature of the Month: Plumose Anemone

Plumose anemonesPlumose anemones (Metridium senile) occur in large numbers in good diving areas in temperate waters. They comprise a tall, smooth column topped with a crown of feathery tentacles. When they contact they look like swirly blobs, as can be seen in our photograph.

Individuals may be white, orange, green or blue in colour. They grow up to 30 cm tall and 15 cm across at the base. They like areas with currents so tend to live on prominent pieces of wrecks or on rocky pinnacles.

Plumose anemone pictureWith fine, delicate tentacles they are unsuited to capturing large animals like fish. Instead they specialise in smaller prey such as small planktonic crustaceans. The anemone’s columnar body is narrower just below the tentacles. A current will bend the stalk at this point and expose the tentacles broadside to the flow in the best position for feeding on suspended matter.

Plumose anemone photographThe Plumose anemone occurs from the Bay of Biscay (North of Spain) to Scandinavia in the northeast Atlantic, and on the west and east coasts of North America. It is unknown from the western basin of the Mediterranean but has been seen in the Adriatic, where it is believed to have been introduced. It has also been seen in Table Bay Harbour in South Africa where it was probably introduced from Europe.

Great photo of a plumose anemone and jellyfish

Further Reading:
Great British Marine Animals, by Paul Naylor
Ask Nature

What do you think of this news item? Join a discussion.