2006 - Corals and Anemones
Date of Issue: 2nd November 2006.
Of all the wonderful marine creatures living in the cool, clear waters around Alderney, the sea corals and anemones are without doubt the most colourful. Together with jellyfish they belong to the phylum Cnidaria, which references the cnida, or stinging cells, that they all possess.
Anemones consist of a central column, containing the mouth and digestive cavity, surrounded by a ring of hollow tentacles. Each species has evolved to live in a specific part of the undersea environment. Some thrive on the seashore while others prefer the deeper water of Alderney's rocky reefs and shipwrecks.
The Burrowing Anemone
Cerianthus lloydii (1p) is one of a few species that has evolved to live in the seabed rather than attached to rock walls or boulders. Its elongated column resides in a parchment-like tube that reaches down into the sand anchoring the anemone and providing a refuge into which the double row of tentacles can be quickly withdrawn if danger approaches.
The Colonial Anemone Parazoanthus axinellae
As its name suggests, the Colonial Anemone Parazoanthus axinellae (2p) forms clusters of individuals all joined together at their base. They live in deeper water near the bottom of rocky walls.
Jewel Anemones Corynactis viridis
The 3p and 8p stamps feature Jewel Anemones Corynactis viridis which live well below the low water mark, carpeting the vertical granite walls in swathes of iridescent colour. They occur in a myriad of colour combinations with a bobble of contrasting hue at the tip of each tentacle.
The 4p stamp shows Sagartia elegans, sometimes called the Elegant Anemone. It has up to two hundred tentacles and occurs in a huge variety of colours.
Metridium senile. When it comes to reproduction, the Plumose Anemone (6p) has an unusual approach. Tiny scraps of tissue are torn from the base of the anemone's column, each developing into a miniature version of the adult.
The 9p stamp features Actinothoe sphyrodeta, another Anemone that prefers the more stable environment beneath the low tide line. It grows on rocks and boulders but, as shown here, is just as likely to be seen attached to the lower part of kelp fronds.
The Snakelocks Anemone
Anemonia viridis (10p) lives in rock pools and shallow water down to about fifteen metres. It is sometimes home to a tiny, purple-striped prawn although the exact relationship between the prawn and its host is yet to be discovered.
The Beadlet Anemone
Actinia equina, varnished & embossed on the £1 stamp, is the anemone that most of us are familiar with. It is often seen on the seashore as a blob of red jelly left on the rocks as the tide retreats. Once underwater its tentacles blossom and the anemone is transformed into a beautiful flower-like animal with a battery of stinging cells, a fatal trap for any small creature unfortunate enough to venture too close.
Eunicella verrucosaChannel Island waters are home to at least nine different species of coral. While they do not form the vast reefs of their tropical cousins, they lack none of their colour or beauty. The most recognisable of these colourfull corals is the Fan Coral Eunicella verrucosa (7p) which grows across the prevailing tidal flow so that its polyps can feed on the blizzard of plankton swept by on the current. It grows just one centimetre a year making the largest fans over seventy years old.
Alcyonium glomeratum (5p) is a soft coral. Its gelatinous digits are covered with delicate white polyps that emerge when the tide is at its strongest to catch particles of food to feed the whole colony.
Leptopsammia pruvoti Although they often live close together, cup-corals live independently, each one consisting of a solitary polyp growing from a calcareous, vase-shaped cup. The most dazzling example is the Sunset Cup-Coral Leptopsammia pruvoti varnished & embossed on the £2 stamp. A Mediterranean species rarely found around the British mainland, its presence in Alderney's waters is a reminder of the continental influence on the marvellous marine life of the Channel Islands.