Alcyonium palmatum
A colonial soft coral with finger-like red lobes.
Alcyonium palmatum, called red dead man's fingers, is a soft coral belonging to the family Alcyoniidae. It grows in colonies that look like clumps of red, fleshy, finger-shaped lobes. Its surface contains many sclerites that form a crust. When feeding, the individual polyps—white and translucent—extend from the leathery surface, giving the colony a furry look. The whole colony can greatly expand or shrink by taking in or expelling water.
This species lives along the Mediterranean and Atlantic coasts of northwestern Europe, from Portugal up to Norway. The colonies attach to bedrock, boulders, stones, and sometimes to crab or gastropod shells. They are most common in areas with strong water movement and where sunlight is too weak for algae to dominate. They typically occur in the sublittoral zone, down to about fifty meters deep.
Most colonies are either male or female, though a few hermaphrodites exist. Growth happens mainly in the first half of the year; polyps become inactive in late summer, and the base tissue turns reddish or brownish as algae and hydroids grow on it. During this time, gonads develop, and spawning takes place in December and January. Polyps feed at various times of day with their tentacles extended. They are suspension feeders, using cilia to gather plankton from the water and absorbing oxygen at the same time.
Quick Facts
- Taxon
- Alcyonium palmatum
Facts from the source article.
Lore & Background
Red dead man's fingers is a colonial coral forming clumps of red fleshy masses of finger-like lobes. The surface layer includes many sclerites which form a crust. The individual polyps are white and translucent, and project from the leathery surface when feeding, giving the colony a furry appearance. By swallowing or ejecting water an entire colony can expand or shrink considerably.
The species is found along the Mediterranean and Atlantic coasts of north west Europe from Portugal to Norway. The polyps live in colonies attached to bedrock, boulders, stones and occasionally the shells of crabs and gastropods. They are most plentiful in areas with strong water movement and where there is insufficient sunlight for algae to predominate. They are usually found in the sublittoral zone down to about fifty metres.
Colonies are nearly always either male or female, although a small number of hermaphrodite colonies are found. Colony growth occurs mainly in the first half of the year with the polyps becoming inactive in late summer, and the base tissue turning reddish or brownish due to the growth of algae and hydroids on the surface. At this time the gonads are developing and spawning occurs in December and January. The polyps feed at various times of the day with their tentacles extended. They are suspension feeders gathering plankton from the water with the help of cilia, and absorbing oxygen at the same time.
Reader's Guide
Alcyonium palmatum, or red dead man's fingers, is a soft coral of the family Alcyoniidae. Its significance lies in its distinctive colonial form, consisting of red fleshy finger-like lobes with a leathery surface crusted with sclerites. The species is notable for its ability to expand or shrink by controlling water intake. It is found along the Mediterranean and Atlantic coasts of north west Europe from Portugal to Norway, typically attached to bedrock, boulders, stones, or occasionally crab and gastropod shells. It thrives in areas with strong water movement and low sunlight, in the sublittoral zone down to about fifty metres. The colonies are predominantly either male or female, with rare hermaphrodites. Growth occurs mainly in the first half of the year, with polyps becoming inactive in late summer and spawning in December and January. The polyps are suspension feeders, using cilia to gather plankton and absorb oxygen. The species' ability to change size and its seasonal reproductive cycle contribute to its ecological role in its habitat.
Did You Know?
- The polyps are white and translucent, giving the colony a furry appearance when feeding.
- Colonies can expand or shrink considerably by swallowing or ejecting water.
- The base tissue turns reddish or brownish in late summer due to algae and hydroid growth.
Frequently Asked Questions
What is Alcyonium palmatum?
Alcyonium palmatum, commonly called red dead man's fingers, is a colonial soft coral in the family Alcyoniidae. It forms dense clumps of fleshy, finger-shaped red lobes that anchor to hard substrates such as bedrock and boulders.
What does Alcyonium palmatum look like?
The colony presents as a cluster of red, leathery, finger-like lobes whose surface is encrusted with tiny skeletal elements known as sclerites. When the white, translucent polyps extend to feed, the whole colony takes on a distinctly furry appearance.
Where can you find Alcyonium palmatum?
This species ranges along the Mediterranean and Atlantic coasts of northwestern Europe, from Portugal up to Norway. It lives in the sublittoral zone, attaching to bedrock and boulders down to roughly fifty metres.
How does Alcyonium palmatum feed and move?
Individual polyps extend from the leathery surface to capture plankton, while the entire colony can dramatically swell or contract by absorbing or expelling water. This expansion-and-shrinking cycle is central to its daily feeding behaviour.
When does Alcyonium palmatum reproduce?
The spawning season for this coral falls in December and January. During that window the colony releases gametes into the surrounding water to complete its reproductive cycle.
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