''Alcyonium palmatum'' or red dead man's fingers is a
species of
soft coral in the family
.
Description
Red dead man's fingers is a colonial coral forming clumps of red fleshy masses of finger-like lobes. The surface layer include 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.
Distribution and habitat
Red dead man's fingers 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
crab
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...
s and
gastropod
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...
s. 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
The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth.
From the point of view of marine biology it forms a relatively stable and well-illuminated ...
down to about fifty metres.
[
]
Biology
The colonies of red dead man's fingers are nearly always either male or female, although a small number of hermaphrodite
In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes.
Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...
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 feeder
Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feedin ...
s gathering plankton from the water with the help of cilia, and absorbing oxygen at the same time.[
]
References
{{Authority control
Alcyoniidae
Corals described in 1766
Taxa named by Peter Simon Pallas